Dissertations/Thesis

Clique aqui para acessar os arquivos diretamente da Biblioteca Digital de Teses e Dissertações da UFRN

2024
Dissertations
1
  • BIANCA VILLAR CARVALHO GUERREIRO
  • Landscape attributes effects on the blond titi monkey (Callicebus barbarabrownae, Hershkovitz 1990)

  • Advisor : MIRIAM PLAZA PINTO
  • COMMITTEE MEMBERS :
  • CARLA CRISTINA GESTICH
  • GERSON BUSS
  • MIRIAM PLAZA PINTO
  • RAONE BELTRÃO MENDES
  • Data: Feb 23, 2024


  • Show Abstract
  • Habitat loss and fragmentation, exacerbated by the expansion of human activities, are currently the greatest threats to biodiversity. Forest-dependent species such as neotropical primates are among the most vulnerable to these changes. The blond titi monkey (Callicebus barbarabrownae) is a medium-sized primate endemic to the Caatinga and currently classified as Critically Endangered. As C. barbarabrownae is a forest-dependent frugivorous primate, it is strongly threatened by habitat loss. This master thesis is divided into two chapters. In the first chapter, we investigated the spatial patterns and temporal changes in land use and land cover (LULC) classes in the geographic range of C. barbarabrownae and in landscapes with records (presence and absence) of this species. Callicebus barbarabrownae occurrence data were obtained from literature searches. The LULC data, used in both chapters, belong to Collection 7 of MapBiomas. Our results highlight that more than half of C. barbarabrownae's distribution area is currently covered by Farming and Non-Vegetated Areas, with Pasture as the predominant class. In landscapes where the species occurs, Savanna Formation, Pasture, Mosaic of Uses, and Forest Formation were the predominant classes. Pasture has a higher coverage proportion in landscapes of occurrence than in landscapes of absence and is the LULC class with the highest rate of increase over the years. The second chapter investigated the effect of landscape attributes on the density of C. barbarabrownae groups. Density data were collected in the field, from five expeditions carried out in different regions of the species' geographic range in the states of Bahia and Sergipe. We found group densities higher than those previously reported for the species. The models that best explained the variation in C. barbarabrownae group density included forest cover, chronic anthropogenic disturbance index (CDI), and clumpiness index as predictor variables in 300 ha landscapes. Group density is negatively related to forest cover, while CDI and clumpiness negatively affect the group density, although not significantly. Our results suggest that extensive livestock farming is currently the greatest threat to C. barbarabrownae, a species that is occurring in contexts of limited habitat availability. At the same time, group density is higher in landscapes with lower forest cover and remnants of more dispersed habitats, suggesting that groups are confined to the limited available habitat. This scenario raises concerns about the long-term viability of populations of this species, whose apparent persistence in such landscapes may be due to an extinction debt. Restoration efforts, especially in the northeastern and central regions of C. barbarabrownae's geographical range, and the establishment of Protected Areas, can serve as crucial allies in the preservation of this species.

2
  • CICERO SIMÃO LIMA SANTOS
  • Influence of habitat structure on the occupancy patterns of threatened insectivorous birds  of the Atlantic Forest

  • Advisor : MAURO PICHORIM
  • COMMITTEE MEMBERS :
  • CARLOS ROBERTO SORENSEN DUTRA DA FONSECA
  • GUILHERME SANTOS TOLEDO DE LIMA
  • MAURO PICHORIM
  • Data: Feb 26, 2024


  • Show Abstract
  • The Atlantic Forest is the second largest forest in South America, considered a biodiversity  hotspot for being one of the most diverse biomes in the world and facing serious threats  due to increasing ecosystem degradation. Birds constitute a particularly affected group  by Atlantic Forest degradation, with many facing imminent extinction threats resulting from  habitat loss caused by deforestation. To prevent biodiversity losses, it is essential to  understand the effects of habitat fragmentation and assess how species respond to  landscape changes. Occupancy modeling has been a widely used approach to investigate  species persistence in fragmented landscapes. Through this approach, it is possible to  identify priority areas, enabling the creation of conservation units, and to support the  formulation of more effective public policies. The aim of this study was to test how habitat  characteristics, at different spatial scales, affect the occupancy of threatened insectivorous  birds in Atlantic Forest fragments. We conducted the study in 11 forest fragments in the  states of Rio Grande do Norte and Paraíba. Species detection was performed using  autonomous recorders distributed at eight randomized points in each fragment. We  collected habitat information at three spatial scales: landscape scale, fragment scale, and  micro-habitat scale. The target species were threatened insectivorous birds of the Atlantic  Forest. The occupancy probability of each species (ψ) was estimated using static occupancy  modeling, which considers imperfect detection. The analyses were performed using the  MARK program. Among the threatened species occurring in the northeastern Atlantic  Forest, six were recorded: Xenops minutus, Herpsilochmus pectoralis, Conopophaga  cearae, Picumnus pernambucensis, Xiphorynchus atlanticus, and Automolus lammi. Overall,  the occupancy of all species was influenced by micro-habitat and fragment variables, and  only X. atlanticus was influenced by landscape variables. The species responded  differently to variables at the various proposed scales. Notably, fragment and micro habitat-associated variables stood out, demonstrating to be the scales with the highest  number of variables influencing species occupancy. The lowest occupancies were for X.  atlanticus (ψ = 0.001), A. lammi (ψ = 0.003), P. pernambucensis (ψ = 0.02), and C.  cearae (ψ = 0.08), while the highest were for H. pectoralis (ψ = 0.16) and X. minutus (ψ = 0.89). We emphasize the crucial importance of conducting studies that assess the effects  of fragmentation at multiple scales to obtain valuable information and promote the  conservation of threatened forest birds in the Neotropical region.

3
  • CLAUDIO BELLINI
  • Green turtles on the Atlantic Island of Fernando de Noronha, Brazil. Thirty-five years of protection (1988-2022): reproductive ecology, population trends, and conservation.

  • Advisor : EDUARDO MARTINS VENTICINQUE
  • COMMITTEE MEMBERS :
  • CECÍLIA BAPTISTOTTE
  • CARLOS ROBERTO SORENSEN DUTRA DA FONSECA
  • EDUARDO MARTINS VENTICINQUE
  • Data: Feb 26, 2024


  • Show Abstract
  • Knowledge of ecological parameters and population trends are key for species  of conservation concern. For marine turtles, annual nest counts are commonly used  for estimating population size. However, complementary information on  reproductive parameters is needed for reliable population estimates. In Brazil,  green turtles (Chelonia mydas) nest mainly on oceanic islands. This study uses long term beach monitoring data (35 years) to describe the reproductive biology and  population trends for green turtles at the Fernando de Noronha Archipelago,  Brazil. There was an increasing trend in the annual number of nests over the  studied period. The average annual number of nests in the first five years of  monitoring (1988-1992) was 38.6 nests, while in the last five years (2018-2022)  it was 285.6 nests. Internesting intervals ranged from 9 to 17 days (mean +- SD  = 11.7 ± 1.3 days; median = 12, n = 1236). Remigration intervals of 3 years  were the most frequent (range 2 to 16 years). The longest reproductive life span  observed was 25 years. Average hatching success was 75.6% (SD = 24.8, range  = 0-100, n = 2612 nests). The growth in the annual number of green turtle nests  observed in Fernando de Noronha suggests conservation efforts initiated in the  1980s likely contributed to the recovery of this population. However, the small  population size and restricted nesting geographic distribution, coupled with the  existence of threats such as fishing and climate change, makes this population still  of conservation concern. Knowledge of ecological parameters and population  trends are key for species of conservation concern. For marine turtles, annual nest  counts are commonly used for estimating population size. However,  complementary information on reproductive parameters (e.g. clutch parameters,  internesting intervals, clucth frequency, remigration interval) is also needed for  reliable population estimates. In Brazil, green turtles (Chelonia mydas) nest mainly  on oceanic islands. This study uses long-term beach monitoring data (35 years) to  describe the reproductive biology and population trends for green turtles at the  Fernando de Noronha Archipelago, Brazil. An increasing trend in the annual  number of nests was found over the studied period. The average annual number  of nests in the first five years of monitoring (1988-1992) was 38.6 nests, while in  the last five years (2018-2022) it was 285.6 nests. Internesting intervals ranged  from 9 to 17 days (mean +- SD = 11.7 ± 1.3 days; median = 12, n = 1236).  Remigration intervals of 3 years were the most frequent (range 2 to 16 years).  The longest reproductive life span observed was 25 years. Average hatching  success was 75.6% (SD = 24.8, range = 0-100, n = 2612 nests). The growth in  the annual number of green turtle nests observed in Fernando de Noronha  suggests conservation efforts initiated in the 1980s likely contributed to the  recovery of this population. However, the small population size and restricted  nesting distribution, coupled with the existence of threats from fishing and climate  change, makes this population still of conservation concern.

4
  • THOMAZ GABRIEL BARROS DA ROCHA
  • Seeds functional traits and germination strategies in a seasonally dry tropical forest


  • Advisor : GISLENE MARIA DA SILVA GANADE
  • COMMITTEE MEMBERS :
  • GISLENE MARIA DA SILVA GANADE
  • LEONARDO HENRIQUE TEIXEIRA PINTO
  • VANESSA GRAZIELE STAGGEMEIER
  • Data: Feb 26, 2024


  • Show Abstract
  • In seasonally dry tropical forests, water is a limiting resource for germination and plant growth. Therefore, dormancy, orthodoxy and storage of reserves represent functional traits that coordinate strategies of resistance to desiccation in seeds, and are crucial for ensuring the survival of species, especially during periods of water restriction. Combining this theoretical knowledge with restoration initiatives is the key to ensuring the successful restoration of these forests. This dissertation intends to understand the dynamics of investment in functional characteristics of seeds and how they affect the germination process in seasonally dry forests of the Caatinga. For this purpose, we used germination tests and quantified seed size, stored reserves and seed coat investment for 22 native tree species. In the first chapter, we aimed to answer how the occurrence of seed dormancy modulates germination strategies, and to propose suitable methodologies for seedling production. We found species that produce non-dormant seeds or seeds with physical dormancy, presenting two strategies for colonizing the environment that are influenced by the size of the seeds and the speed of germination. The species produce seeds that use dormancy or orthodoxy as strategies to distribute germination over time and tolerate the dry period in the seed banks. In the second chapter, we tested how the functional traits of seed protection and nutrition affect germination strategies. Trade-offs related to size, stored reserves, tegument and germination speed, coordinate acquisitive and conservative strategies to scape or tolerate the period of low water availability, generating a desynchrony in the recruitment period. In the acquisitive group, small seeds with few reserves invest in more seed coat as a form of protection and germinate fast. In the conservative group, large seeds invest in storing more reserves and germinate slowly. Therefore, this research provides an insight into the different strategies used by plants to produce seeds in the seasonally dry forests of Caatinga, ensuring the survival and colonization of this dry environment. In addition, we have contributed to methodological advances for ecological restoration, maximizing seedling production in the greenhouse.

5
  • VICTOR ROCHA DI CAVALCANTI
  • Land-use and flow intermittence influence biodiversity-stability relationships across spatial scales: implications for an uncertain future

  • Advisor : ANDROS TAROUCO GIANUCA
  • COMMITTEE MEMBERS :
  • VICTOR SATORU SAITO
  • ADRIANO CALIMAN FERREIRA DA SILVA
  • ANDROS TAROUCO GIANUCA
  • Data: Feb 26, 2024


  • Show Abstract
  • Global change and associated increasing anthropogenic pressures on Earth are impacting biodiversity locally, regionally and globally, with negative consequences on the stability of ecosystems. However, the majority of studies on biodiversity-stability relationships have been conducted locally. Only recently it has been proposed that such relationships could become decoupled across spatial scales. Spatial decoupling happens when many local communities are unstable, but they vary asynchronously in space, leading to regional stabilization. Spatial decoupling can thus result in misleading interpretation of local scale stability patterns when the goal is to design regional management strategies. Focusing on multiple metacommunities of French rivers experiencing contrasting levels of flow intermittence, we investigate (i) whether and how land-use influences macroinvertebrate diversity and stability across multiple spatial scales and (ii) whether connectivity loss due to increasing intermittence enhances the relative stabilizing force of spatial asynchrony over local stability, resulting in higher spatial decoupling of diversity-stability relationships. We found that urbanization and agriculture negatively influenced local species diversity and the spatial asynchrony of populations and communities, indirectly reducing the stability of metacommunities through different pathways. However, the significance and strength of those pathways changed depending on the intermittence level and organism group analyzed. Specifically, the diversity of aerial organisms responded strongly to urbanization, whereas the diversity of aquatic species did not. In addition, the relative contribution of spatial asynchrony to regional stability was higher for metacommunities of intermittent than perennial rivers, implying the need to conserve multiple sites to attain regional stability in those systems. Considering that climate change is increasing flow intermittence across river networks, our results suggest that managers need to focus on the spatial dynamics of metacommunities more than on local-scale processes to monitor, restore and conserve freshwater biodiversity.

6
  • DORGIVAL DIÓGENES OLIVEIRA JÚNIOR
  • EFFECTS OF HABITAT STRUCTURE ON THE OCCUPANCY PATTERNS OF FRUGIVOROUS BIRDS IN FOREST FRAGMENTS OF THE BRAZILIAN ATLANTIC FOREST

  • Advisor : MAURO PICHORIM
  • COMMITTEE MEMBERS :
  • CARLOS ROBERTO SORENSEN DUTRA DA FONSECA
  • MARCO AURELIO PIZO FERREIRA
  • MAURO PICHORIM
  • Data: Feb 27, 2024


  • Show Abstract
  • Tropical forests are arguably the most biodiverse natural ecosystems in the world. Yet they are constantly being destroyed by human action, impacting various ecosystem services due to the impoverishment of ecological relationships resulting from the biodiversity losses they face. Frugivorous birds play a crucial role in tropical forests, acting as seed dispersers and promoting environmental recovery in disturbed landscapes. Therefore, understanding the factors that influence the occurrence of these birds in fragmented tropical forests is fundamental for the conservation of these ecosystems. Such information is essential to guide control and management measures that favor the permanence of this group of birds in impacted areas, ensuring the continuity of the environmental services they provide. Here, we investigated how habitat structure at multiple spatial scales affects the occupancy patterns of frugivorous birds. We conducted the study in 11 forest fragments located in the north of the Pernambuco Endemism Center, in the Brazilian Atlantic Forest. We recorded species detection data using autonomous recorders at each sampling site for three consecutive days. We estimated the probability of species occupation considering imperfect detection, using three spatial scales (landscape, fragment and micro-habitat). We found that frugivorous bird species responded to different habitat structure characteristics in Atlantic Forest fragments. At the landscape scale, most species were more likely to occupy areas with rougher terrain, greater presence of natural forest formations and less coverage of non-vegetated areas. On the fragment scale, most species showed greater occupation in larger, more circular fragments, closer to the core of the Pernambuco Endemism Center and with more intact forests. On the micro-habitat scale, the species showed greater occupation in places with taller trees and greater complexity in the understory. In addition, greater occupation was observed in areas closer to the edges of fragments, with the exception of one species which showed greater occupation in areas further away from forest edges. Our research emphasizes that in order to ensure greater occupation by frugivorous birds and preserve their ecological functions in the ecosystem, it is recommended to implement protection measures in the remaining forest areas, promote the recovery of degraded areas and carry out projects to conserve the structure of the local vegetation in the forest fragments.

7
  • INGRID ELAINE RODRIGUES DOMINGOS
  • Salinization causes rapid evolution of tolerance and smaller cell size in a common bloom forming cyanobacteria

  • Advisor : KEMAL ALI GER
  • COMMITTEE MEMBERS :
  • KEMAL ALI GER
  • SANDRA MARIA FELICIANO DE OLIVEIRA E AZEVEDO
  • VANESSA BECKER
  • Data: Feb 28, 2024


  • Show Abstract
  • Global changes act as selective forces responsible for inducing the genotypic adaptation (evolution)  in species over a short period, with little or no information about subsequent ecological effects. As a stress factor in freshwater ecosystems, salinization not only poses a threat to biodiversity and the primary functions and services of ecosystems but also imposes selective pressure on species. However, the way species adapt locally to salinization through microevolutionary processes is poorly understood. Therefore, we investigated the genotypic adaptation capacity of the cyanobacterium Microcystis aeruginosa, a major contributor to global blooms, to increased salinity and the resulting changes in growth and morphology. For this purpose, we conducted a Common Garden experiment with four toxin-producing strains of Microcystis. Before the Common Garden experiment, all strains were divided into three populations (replicas) and exposed to two treatments: the addition of  NaCl (1.5 g/L) and the control (0 g/L of NaCl) for over 100 generations (6-8 months). After this period, each population was exposed to treatments of 0, 1.5, 3, and 5 g/L of NaCl with 3 replicas each in a Common Garden project for an additional 7 generations in order to remove the effects of phenotypic and epigenetic adaptation. After this stage, growth and morphological characteristics were measured. To test how salinity concentrations and fitness factors affect Microcystis growth and morphology, we used Generalized Linear Models. Populations exposed to a concentration of 1.5 g/L during the selection stage (adapted) showed higher growth rates compared to those exposed to the control (non-adapted) and grew in all salinization treatments, indicating an increased salt tolerance driven by selection in genetic variation. Selection also resulted in smaller cell sizes for all strains. Two strains originally grown as individual cells produced colonies in higher salinities. The formation of colonies and colony size increased in non-adapted populations, indicating that adapted populations probably do not need to invest in colony formation in order to survive. The results demonstrate that adaptation to relatively low concentrations (1.5 g/L) of salt also allows tolerance to higher salinities (>3 g/L). We have shown, for the first time, the rapid evolutionary adaptation of a common aquatic primary producer to freshwater salinization over ecological time, with effects on key traits such as  cell size. Such adaptation is likely to occur in other cyanobacteria and phytoplankton species in nature where salinization occurs, with consequences for ecosystem functions and services that are still unknown. Our results justify a broader view of the eco-evolutionary implications of salinization-driven selection in aquatic ecosystems.

8
  • URSULA TATHIANA OLIVEIRA DE MEDEIROS
  • Forest carbon sequestration for different ecological restoration techniques in the Caatinga

  • Advisor : GISLENE MARIA DA SILVA GANADE
  • COMMITTEE MEMBERS :
  • GISLENE MARIA DA SILVA GANADE
  • FELIPE FERREIRA MONTEIRO
  • JEANNE RAQUEL DE ANDRADE FRANCO
  • Data: Feb 29, 2024


  • Show Abstract
  • Ecological restoration plays a crucial role in overcoming the urgent challenges related to ecosystem degradation, biodiversity loss and climate change. In regions such as the Caatinga, which faces unique climatic challenges, restoration can be an ally as a technique to promote carbon sequestration in degraded areas, strengthening the potential for climate change mitigation. This study seeks to identify effective restoration techniques and assess their impact on carbon accumulation, tree species development and seedling characteristics, with the aim of optimizing biomass production in semi-arid ecosystems. The research involved six tree species native to the Caatinga and implemented five planting treatments in 12m x 8m plots with 2m spacing, replicated five times. These treatments included the control (no manipulation), irrigation, transposition of litter, a combination of transposition of litter and irrigation, and agroforestry. The seedlings were categorized based on the dimensions of the roots (small or large) and the aerial part (small or large), and measurements of height, diameter at ground height, aerial biomass and water content of the plants were recorded three years after restoration, at the end of the experiment. Our results revealed that the addition of water had a significant impact on carbon accumulation. Jurema preta (Mimosa tenuiflora) proved to be the most promising species for greenhouse gas neutralization projects, accumulating approximately 0.09 kg of carbon per m2. The research also looked at the importance of the size of the seedlings, indicating that plants with larger roots and aerial parts accumulated more biomass and had a higher survival rate. In addition, the Catingueira species showed excellent survival in water-restricted treatments, especially when the seedlings had small roots. The total carbon accumulated at the end of the experiment was 0.1 kg per m2. These findings offer guidelines and strategies for management and restoration, highlighting the importance of taking into account not only the availability of water, but also the particularities of the species and the size of the seedlings in order to maximize the effectiveness of restoration projects in the Caatinga.

9
  • NIEGE FELIX CAETANO FRANÇA
  • ASSESSING THE INFLUENCE OF DIVERSITY AND FACILITATION ON FLOWER AND FRUIT AVAILABILITY IN RESTORED TREE COMMUNITIES

  • Advisor : GISLENE MARIA DA SILVA GANADE
  • COMMITTEE MEMBERS :
  • ANDREA LEME DA SILVA
  • GISLENE MARIA DA SILVA GANADE
  • MARINA ANTONGIOVANNI DA FONSECA
  • Data: Feb 29, 2024


  • Show Abstract
  • Given the current state of degradation of the Caatinga Biome, ecological restoration strategies are of the utmost importance, not only to halt this degradation process, but also to restore the affected communities, making them stable and productive over time. Caatinga restoration programs that seek out new ecological restoration technologies have shown themselves to be promising alternatives for combating the desertification process. For more than a decade, UFRN's Restoration Ecology Laboratory has been developing innovative technologies for planting tree species belonging to the biome, with the aim of combating desertification. This technique enabled the construction of the BrazilDry experiment, the first large-scale experiment to restore the Caatinga, which is currently receiving support from the CNPq as a Long-Term Ecological Project (PELD). This experiment is linked to the international TreeDivNet network, which includes 29 experiments in 20 countries that test the influence of tree species diversity on the functioning of planted forests. In addition to testing the effect of species diversity, this experiment also tests how the facilitating potential of these species influences the performance of restored plant communities. In this way, the work aims to generate technologies applicable to restoration programmes for degraded areas of the Caatinga that promote the resilience and resistance to desertification of the restored ecosystem in the long term. Implemented in 2016, the BrazilDry experiment creates Caatinga restoration models that can make preserving plant biodiversity compatible with better ecosystem functioning. This study is divided into two chapters, both carried out in the BrazilDry Experiment, and aims to understand how diversity and facilitation mechanisms influence the flowering and fruiting patterns of restored communities. In the first chapter, our main objective is to test whether the diversity of tree plants in the restored communities and their facilitation potential influence the number of reproductive individuals in the first 7 years of restoration, and thus answer: I - How many individuals and of which plant species in the restored communities have managed to reproduce in the last 7 years of restoration? II - Whether there is an effect of diversity and/or facilitation on the presence or absence of flowering and fruiting patterns. As a result, we observed that the diversity of trees planted did not influence the flowering capacity of the species. However, there was a positive effect of Facilitation on the flowering capacity of species in the first 7 years of restoration. Diversity and facilitation did not influence fruiting patterns. This may have been due to the low rainfall which causes many flowers to abort, as well as fruit abscission, which can also be produced in smaller quantities when under great water stress. The second chapter assesses how the diversity of species that make up the restored communities affects the phenophases of the species Piptadenia retusa, popularly known as Jurema-branca, in terms of the quantity and the synchronization of fruit, flower and leaf production by this species. With the specific objectives of: I - To test whether the diversity of trees in the restored community influences the number and timing of flower and fruit production by the species P. retusa, and which months produce these food resources for the fauna; II - To test whether the diversity of species in the restored tree communities influences the maximum production capacity of flowers, fruit and leaves produced by Piptadenia retusa over the course of a year. As a result, we observed flowering peaks in the wettest months between March and June, while fruiting also occurred in the first half of the dry season between June and November. The production of floral resources (buds and flowers) and seed production (ripe and immature fruit) differed not only in relation to the months, but also increased significantly with the increase in the diversity of trees making up the restored community. In terms of maximum production capacity expressed by the Fournier index, only the explanatory variable, time, had a significant influence. All the variables showed maximum production in the wettest months, with the exception of mature fruit production, which occurred more intensely in the driest months. Leaf production was, on average, 75 percent of its production capacity in the wettest months, but still maintained 25 per cent of its production capacity during the driest months. This work indicates that restoration models with the presence of nurse or facilitator species should be implemented, given the potential of these species to increase the reproductive capacity of neighboring trees, as well as demonstrating that the diversity of trees planted in restoration programmes can increase the reproductive capacity of some species, thus promoting the replacement of individuals in the community and the availability of food for the pollinator fauna.


10
  • MARIA CAROLINA DE OLIVEIRA PACHECO
  • Do environments with greater temperature variation select more thermally resistant corals?

  • Advisor : GUILHERME ORTIGARA LONGO
  • COMMITTEE MEMBERS :
  • SAMUEL COELHO DE FARIA
  • AMANA GUEDES GARRIDO
  • GUILHERME ORTIGARA LONGO
  • Data: Mar 1, 2024


  • Show Abstract
  • Global changes have been causing increase in frequency and severity of coral bleaching events, contributing to coral mass mortality and reef degradation. Despite that, in some reefs, corals show different susceptibilities to bleaching and distinct abilities to recover after stress events, as some corals have bleached less and survived more under thermal anomalies. This pattern might be related to natural temperature variability in corals’ origin sites, which may influence different coral mechanisms to cope with thermal stress, through adaptation or acclimatization to local conditions. We conducted laboratory and field experiments with Siderastrea stellata colonies from habitats with high (tide pools), medium (shallow reef; 2m) and low temperature variability (deep reef; 28m), to evaluate coral response to thermal stress and its potential to acclimatize in environments with different temperature dynamics. Tide pool corals bleached less and did not suffer great decrease in photosynthetic efficiency when exposed to thermal stress, whereas corals from more thermally stable environments (shallow and deep) showed higher vulnerability to bleaching and underwent alarming decrease in photosynthetic efficiency. Deep reef corals also bleached and suffered reduction in photosynthetic efficiency when they were transplanted to reefs with more prominent temperature variation. Our results revealed that tide pool corals are more resistant than corals from shallow and deep reefs, suggesting that high temperature variability selects tolerance mechanisms that favor corals permanence in these thermally variable sites, while also making them more prepared to deal with climate change.

11
  • JOSE ONOFRE NASCIMENTO MONTEIRO
  • Patterns of Occupancy and Use in the Semi-Arid Portion Of The Brazilian Coastline by Migratory Shorebirds)

  • Advisor : MAURO PICHORIM
  • COMMITTEE MEMBERS :
  • MAURO PICHORIM
  • CARLOS DAVID DA SILVA OLIVEIRA
  • FLOR MARIA GUEDES LAS-CASAS
  • Data: Mar 25, 2024


  • Show Abstract
  • Many shorebird species are associated with coastal ecosystems during their annual migratory movements between breeding and overwintering areas. The semi-arid coastal region of northeastern Brazil presents a vast landscape of suitable habitats for these birds. Investigating the use of these habitats by shorebirds as a function of landscape structure and anthropic disturbances is a useful approach to better understand their occupancy patterns in the semi-arid region. In 2022 and 2023 we conducted n=3 independent data sampling campaigns, representing n=111 individual 1km long transects, totaling 804 km, covering the entire coastline of Ceará and part of Rio Grande do Norte. Presence/absence data for the species (Calidris canutus, Calidris pusilla, Limnodromus griseus and Numenius hudsonicus) were collected by means of visual observation using binoculars and spotting scopes. Specific habitat characteristics and other variables, such as proximity to particular habitats, human occupations, and degree of disturbances related to tourism activities were recorded during each transect. In addition, information on landscape variables such as land cover in different classes was collected using satellite images. We analyzed the influence of environmental variables on the occupation of the species through static occupation models, using the MARK program. The three most influential variables in the distribution of the species were the distance from estuaries, urban area coverage and aquaculture. The response of species occurrence along the gradient of variables showed that C. canutus had the lowest occupancy among the species (ψ = 0.31), followed by L. griseus (ψ = 0.44), N. hudsonicus (ψ = 0.71), and C. pusilla (ψ = 0.72). These results indicate the vulnerability of shorebirds to anthropogenic impacts, especially related to habitat loss during the wintering period on the semi-arid Brazilian coast. Our results will help to inform conservation strategies and better define the ecological requirements of this threatened species during the greater part of its non-breeding periods.

12
  • VICTORIA MARIA REIS DE SOUZA
  • The influence of environmental and anthropogenic factors on the presence of resident shorebirds in the Banco dos Cajuais Western Hemisphere Shorebird Reserve Network (WHSRN) Site, coastal of northeast Brazil.

  • Advisor : MAURO PICHORIM
  • COMMITTEE MEMBERS :
  • MAURO PICHORIM
  • FERNANDO AZEVEDO FARIA
  • ANDERSON GUZZI
  • Data: Mar 26, 2024


  • Show Abstract
  • Providing accurate information on population status and habitat preferences is
    essential for developing conservation strategies for shorebirds. Using key
    species to understand patterns of habitat use can contribute and extend
    conservation benefits to other shorebird species that share the same habitat.
    The aim of this study was to analyze the habitat preferences of the endangered
    Wilson’s Plover (Charadrius wilsonia) and the American Oystercatcher
    (Haematopus palliatus), breeding shorebirds residing strictly along the coast.
    We analyzed the presence of the species with environmental and anthropic
    variables, to understand which variables influence the occupancy (Ѱ) and
    detectability (p) probabilities of the species in the Western Hemisphere
    Shorebird Reserve Network site Banco dos Cajuais, in the semi-arid central
    portion of the coastal zone of Brazil. Data were collected from July 2022 to June
    2023. We found that Haematopus palliatus was more present (Ѱ = 0.99) than
    Charadrius wilsonia (Ѱ = 0.87), but both species had a high probability of
    occupancy. We found that the occupancy of Charadrius wilsonia and
    Haematopus palliatus is influenced by variation in the structure of the
    environment and by natural and anthropogenic disturbances. Among the most
    important explanatory variables for species occupancy, a negative influence
    stands out for Charadrius wilsonia between occupancy and the distance from
    river channels and for Haematopus palliatus a positive influence between
    occupancy and the availability of exposed sandy beach soil. The results of this
    work can contribute to the management of areas recognized as priorities for the
    conservation of Charadrius wilsonia and Haematopus palliatus, in addition to helping to identify new areas which have determining factors for the occurrence of the species.

13
  • CARLOS SALUSTIO GOMES
  • VOCAL ACTIVITY, DETECTION, OCCUPANCY, AND POPULATION DENSITY OF OWLS IN FOREST PATCHES OF THE ATLANTIC FOREST


  • Advisor : MAURO PICHORIM
  • COMMITTEE MEMBERS :
  • PRISCILLA ESCLARSKI
  • CARLOS BARROS DE ARAÚJO
  • MAURO PICHORIM
  • Data: Mar 27, 2024


  • Show Abstract
  • Understanding the activity and distribution patterns of animals about environmental factors is crucial for species conservation. In the Atlantic Forest domain, 72% of owl species show population declines, making it essential to conserve both species and habitats. The use of passive acoustic monitoring offers opportunities to collect data on the activity and habitat use of little-studied species, contributing to long-term monitoring and effective conservation. This work seeks to fill gaps in the understanding of vocal activity patterns, detection, and habitat use of owls that occur in the far north of the Atlantic Forest, more specifically, in the north of the Pernambuco Endemism Center, Brazil. Our objectives were: (1) to investigate the vocal activity and detection patterns of two nocturnal owls that occur in the Neotropical region, the Tropical Screech-Owl (Megascops choliba) and the Spectacled Owl (Pulsatrix perspicillata), to contribute to monitoring protocols for the conservation of both species; and (2) to identify the environmental factors that affect the occupancy of P. perspicillata, estimate its population density, and map the hotspots of occupancy and density of the species to aid locate priority conservation areas. In the first part of the study, we found that the vocal activity of P. perspicillata was highest at 9 pm, while that of M. choliba was highest at 7 pm, 1 am, and 4 am. The detection of P. perspicillata was best explained by the effective moon illumination index (p = 0.05) and tree density (p = 0.027) and of M. choliba by air temperature (p = 0.006) and tree density (p = 0.001). In the second part, we identified that P. perspicillata responds to environmental variations both at the patch scale and at the 1000 ha landscape scale, and its occupancy is positively affected by the presence of primary forests and areas with greater topographic roughness. The regions of high occupancy and density are concentrated in protected areas, indigenous lands, and other patches with high potential for conservation. The results of this study may aid to identify favorable scenarios for the efficient monitoring of forest night owls and to establish protocols for the conservation of species that are sensitive to the effects of forest loss and that lack information related to habitat use.

Thesis
1
  • FERNANDA MONICELLI CÂMARA BRITO
  • Application of chemical techniques to mitigate eutrophication and effects on planktonic organisms

  • Advisor : VANESSA BECKER
  • COMMITTEE MEMBERS :
  • VANESSA BECKER
  • JULIANA DEO DIAS
  • HÉRIKA CAVALCANTE DANTAS DA SILVA
  • JOSÉ NEUCIANO PINHEIRO DE OLIVEIRA
  • MARCELA APARECIDA CAMPOS NEVES MIRANDA
  • MARIANA RODRIGUES AMARAL DA COSTA
  • Data: Jan 23, 2024


  • Show Abstract
  • There are several techniques to control eutrophication, physical and chemical techniques have been widely used, however there are few studies on the effects of these techniques in the semiarid region and on planktonic communities. The Floc & Sink and Floc & Lock are geoengineering techniques that aim to manipulate the biogeochemical phosphorus (P) cycle, removing particulate P (algal biomass) by sedimentation (Floc & Sink), and dissolved P from water by adsorption and capping. of the sediment (Floc & Lock). The technique uses a combination of coagulant and clays (natural or modified) for sedimentation and/or adsorption. Therefore, the main goal of this thesis is to analyze the responses of the planktonic community to the geoengineering technique to control eutrophication and its efficiency in spring waters in the tropical semi-arid region. The first chapter aimed to carry out a scientometric analysis of the literature to observe the effect of chemical and physical techniques for controlling eutrophication on planktonic organisms in eutrophic environments, evaluating bibliometric production and determining knowledge gaps. The results showed that the most studied techniques were: Floc & Sink, algaecides, Floc & Lock, aeration, dredging and ultrasound, and that there has been more interest in them over the years. The effects of the technique on other phytoplankton groups, in addition to cyanobacteria and zooplankton, are little addressed, being one of the gaps found. Furthermore, studies that observe the effects over time, showing the succession of the planktonic community and in mesocosms are in the minority. Overall, all chemical techniques removed the biomass or biovolume of cyanobacteria. Unlike physical techniques that had conflicting results, with inconclusive results. The few studies following the application of the technique show positive effects on phytoplankton diversity after Floc & Sink and an increase in richness after Floc & Lock and aeration. All techniques negatively affected zooplankton, decreasing the biomass, survival or abundance of these organisms. Chapter two aimed to analyze the effects on biomass and phytoplankton composition, when applying the Floc & Sink (F&S) mitigation technique, in eutrophicated waters from reservoirs in the tropical semi-arid region. On an experimental scale, a chemical coagulant (Polyaluminum Chloride-PAC) and natural materials (Planossol and limestone beige or white) were used as ballasts for sedimentation and we applied a functional approach, Morphology-Based Functional Groups (MBFG), based on morphological characteristics of phytoplankton (Kruk et al., 2010), to evaluate which adaptive mechanisms are more resistant to sedimentation. The technique was capable of sedimenting algal biomass with the addition of coagulant plus ballast (PAC+Planosso; PAC+Beige Limestone and PAC+White Limestone). The effects of the technique on phytoplankton biomass and composition varied according to the sedimentation resistance mechanism. MBFG IV, without specialized characteristics, sedimented only with the use of coagulant. The presence of mucilaginous sheath and aerotopes (Microcystis aeruginosa, MBFG VII) prevented its sedimentation in all treatments. Neither MBFG V (flagellates) nor MBFG VI (small diatoms) exhibited sedimentation. Furthermore, filamentous cyanobacteria (MBFG VIII) demonstrated greater resistance to sedimentation. The use of natural ballast materials provides an economical alternative for removing algal biomass. The third chapter aims to test the efficiency of the Floc & Lock technique in controlling internal fertilization and removing algal biomass from a eutrophic environment in the semi-arid region. We hypothesized that the technique would be able to immobilize the phosphorus present in the sediment, reducing the release of phosphorus and thus limiting phytoplankton growth. The study was conducted on an experimental scale in PVC tubes containing water and sediment, incubated for 47 days. The treatments were: addition of PAC, addition of Phoslock® (PHOS), PAC + PHOS and PAC+PHOS+Beige Limestone (CB), in addition to the control, without the addition of any treatment. Our results showed that the Floc & Lock technique managed to reduce the release of phosphorus into the sediment and limit phytoplankton growth, confirming the study hypothesis. Although all treatments were efficient in capping the sediment and removing algal biomass, the combination of PAC+PHOS was the one that achieved the lowest phosphorus release rates. However, the PAC+ PHOS+CB and PHOS only treatments also obtained good results in removing algal biomass and capping the sediment, showing more economical application alternatives. 

2
  • ANDERSON DANTAS LEAL
  • Ant diversity patterns at local, regional and global scales

  • Advisor : CARLOS ROBERTO SORENSEN DUTRA DA FONSECA
  • COMMITTEE MEMBERS :
  • MÁRIO RIBIRO DE MOURA
  • JOUDELLYS ANDRADE SILVA
  • ANDROS TAROUCO GIANUCA
  • CARLOS ROBERTO SORENSEN DUTRA DA FONSECA
  • EDUARDO MARTINS VENTICINQUE
  • Data: Feb 23, 2024


  • Show Abstract
  • Biodiversity patterns are affected by factors such as climate, human disturbances and  biotic interactions, which operate at different spatial scales. Understanding diversity  patterns and their determinants is essential for effective conservation efforts. However,  many regions and taxonomic groups are often overlooked due to a lack of adequate data.  In particular, invertebrates and arid/semiarid regions receive less attention. For example,  ants play a fundamental role in ecosystem functioning, but there are knowledge gaps  regarding their global biodiversity patterns, their response to anthropogenic disturbances  and their relationship with plant composition and diversity. Similarly, the Caatinga, a  species-rich dry forest, lacks clear knowledge about its animal diversity patterns.  Therefore, in this thesis we set out to investigate the determinants of ant diversity at three  different scales: (i) global, testing the effect of climate and topography, (ii) regional,  testing the effect of anthropogenic disturbances and (iii) local, testing the effect of tree  species richness and their facilitation capacities. In addition, (iv) we examined the  determinants of animal diversity in the Caatinga and the correlation of diversity  distribution between different animal taxa. In the first chapter we tested the relative  strength of abiotic gradients in determining spatial patterns of ant diversity around the  world and between biogeographic realms. We used multiple regressions to relate global  ant diversity data to climatic and topographic data. Our findings suggest that ant diversity  is higher in tropical regions, especially in areas with higher annual rainfall and higher  average temperature. However, the abiotic determinants between biogeographic realms  varied greatly, which challenges the generality of the global pattern. This highlights the importance of considering regional historical and ecological contexts when investigating  biodiversity patterns. In the second chapter we tested the influence of chronic  anthropogenic disturbances (e.g. logging and grazing) and habitat loss on ant species  richness (total, specialist and generalist species). We then used multiple regressions to  examine the impact of disturbance vectors on ant diversity patterns. We found that habitat  loss reduces species richness at all levels, including specialist and generalist species,  while chronic disturbance has a particularly strong impact on species overall and on  specialist species. Our findings highlight that it is necessary to include the drivers of  chronic disturbance in order to measure our real impact on biodiversity. The third chapter  examines the impact of tree richness, tree facilitation and the presence of plants with  extrafloral nectaries on ant diversity patterns, including species richness, phylogenetic  diversity and abundance. We collected ants in all 155 plots of the BrazilDry project, a  biodiversity experiment established in the Açu National Forest. The plots contain one,  two, four, eight and 16 plant species with varying compositions and a gradient of  facilitation. Our results suggest that plant diversity is the main mechanism responsible for  the richness and phylogenetic diversity of ants in the BrazilDry experiment. Possibly the  result comes from a bottom-up effect in the trophic chain, in which plants provide  essential resources for the ants, increasing their diversity. In chapter four, we examine  the correlation between the distribution of animal diversity in the Caatinga among five  taxonomic groups: birds, reptiles, amphibians, mammals and ants. We also tested the  influence of abiotic factors on the distribution of diversity within these groups. To do this,  we retrieved species distribution maps and climate variables from online databases.  Pearson's correlations were used to test the overlap of diversity between the groups, and  multiple linear models were used to test the relative importance of abiotic factors in  organizing the diversity of these groups. Our findings indicate that animal biodiversity in  the Caatinga largely overlaps, but the response to abiotic conditions varies according to  the taxonomic group analyzed. With this thesis, we have filled important gaps in ant  diversity, distribution, abiotic determinants and responses to tree richness. In addition, we  describe the abiotic determinants and the degree of overlap of animal diversity in the  Caatinga.

3
  • JESSICA BLEUEL
  • TAXONOMIC, FUNCTIONAL, AND TROPHIC DIVERSITY OF CORALS AND RESPONSES TO THERMAL STRESS

  • Advisor : GUILHERME ORTIGARA LONGO
  • COMMITTEE MEMBERS :
  • RALF TARCISO SILVA CORDEIRO
  • BARBARA RAMOS PINHEIRO
  • CYBELLE MENOLLI LONGHINI
  • GUILHERME ORTIGARA LONGO
  • MARCELO DE OLIVEIRA SOARES
  • Data: Feb 23, 2024


  • Show Abstract
  • Corals play unique roles and are critically important in reefs, but they are threatened by
    rising ocean temperatures causing bleaching events that can lead to loss of coverage, diversity, and reef complexity. Considering that approaches based on functional traits can provide insights into their responses to environmental disturbances, understanding patterns of coral diversity and their traits, as well as their responses to climate change, is fundamental. In Chapter 1, we describe the taxonomic and functional diversity of corals in Brazil, evaluating species composition and the functional space occupied among regions. We observe clustering of eight regions, where Bahia holds the highest species richness and proportion of occupied functional space, both decreasing with distance from this region. Species composition and regional distribution are influenced by environmental barriers and filters and related to coral traits. In Chapter 2, we investigated the variation in concentration and composition of fatty acids in shallow water zooxanthellate corals along the Southwestern Atlantic coast (SWA) to indicate their predominant trophic mode and assess potential geographic variations. Species identity and location explained most of the variation in fatty acid composition in the SWA, associated with photosynthetically available radiation (PAR), sea surface temperature (SST), and particulate organic carbon (POC). The fatty acid composition of Favia gravida, Siderastrea stellata, Mussismilia harttii, and Mussismilia hispida varied among locations, while Madracis decactis, Montastraea cavernosa, and Porites astreoides showed a consistent pattern across all locations. Additionally, based on the concentration of the heterotrophic marker (CGA), P. astreoides was the most autotrophic species, and Mu. hispida was the most heterotrophic coral. Coral growth form is also an important attribute due to the addition of calcium carbonate in the reef environment. Therefore, in Chapter 3, we experimentally assessed the relative contribution of autotrophy- and heterotrophy-based feeding modes on the growth of Millepora alcicornis and Mo. cavernosa, and how they respond to thermal stress. We observed a higher growth rate for M. alcicornis than M. cavernosa. The dissolved organic matter (DOM) feeding treatment initially had a positive influence on coral growth, which did not sustain over time for M. cavernosa and was delayed for M. alcicornis. Thermal stress had little impact on growth and the predominant trophic mode of both species. However, it negatively affected the photochemical efficiency (Fv/Fm) and coloration of Mi. alcicornis (temperature-sensitive). Corals subjected to the DOM treatment were less susceptible and showed greater recovery after thermal stress. On the other hand, the health of Mo. cavernosa (temperature-resistant) was not affected by thermal stress.

4
  • KELLY YUMI INAGAKI
  • DIFFERENT PERSPECTIVES OF ECOLOGICAL INTERACTIONS  BETWEEN CORALS, ALGAE AND HERBIVORES

  • Advisor : GUILHERME ORTIGARA LONGO
  • COMMITTEE MEMBERS :
  • CARLOS EDUARDO LEITE FERREIRA
  • GUILHERME ORTIGARA LONGO
  • MARINA NASRI SISSINI
  • NATÁLIA CARVALHO ROOS
  • THIAGO COSTA MENDES
  • Data: Mar 8, 2024


  • Show Abstract
  • Ecological interactions involve all living beings and ecosystems we know. In reef  systems, corals and algae are important organisms that interact with each other in  positive, negative and neutral interactions, and they can be influenced by top-down  (mediated by consumers) and bottom-up (mediated by producers) effects. Reefs and  their complex interactions are threatened by local and global impacts, which can  change their patterns and outcomes of interactions. In this thesis, we explored coral algal-herbivores interactions under different perspectives. In Chapter I, we did a  systematic review involving the last 20 years of studies (2002-2020) and we asked: i)  where these interactions have been explored globally; ii) what are the main organisms  involved; iii) the most frequent outcomes; iv) the effects of herbivores over the  interactions; and v) the effects of climate change. We found that i) Pacific and  Caribbean regions concetrate 86% of interactions; ii) the main organisms involved are  massive and branching corals, and macroalgae and turf, with some variation among  regions; iii) adults corals are mostly harmed by algae suffering sublethal damages,  while juvenile corals can be both harmed or benefitted mainly by recruitment; iv) most  of the studies evaluate the effects of herbivory in indirect ways (e.g. abundance  correlations), with few experimental efforts; and v) the effects of climate change were  explored in only 10% of studies, negatively affecting coral recruitment and causing  sublethal effects, and reducing algal abundance. In Chapter II, we explored coral-algal herbivore interactions in tropical reef in Brazil, evaluating i) their historical  abundances; ii) the current frequency of coral-algal interactions; iii) the outcome of these interactions; iv) how the warming ocean can influence coral-algal interactions,  and v) if different herbivore could mediate coral-algal interactions in the current and  future scenarios of warming. We found that i) benthic cover is stable in the last  decade, reflecting older registers, with algal dominance (60%) and low coral cover  (5.6%), in a scenario that does not seem related to local biomass of herbivores fishes;  ii) coral-algal interactions are frequent and 96% of them involve the coral Siderastrea  stellata interacting with turf; iii) the majority of interaction lead corals to decrease in  phootsynthetic efficiency but this vulnerability varies among coral species; iv) coral algal interaction are equally harmful for corals in current and future scenarios of ocean  warming, carrying among species; v) the dominant macroalgae is little consumed by  different herbivores, regardless of temperature, which indicates low effects of  herbivores over coral-algal interactions. In Chapter III, we explored the effects of iron  enrichment over algal palatability, evaluating different iron concentrations (control,  100 µg/L, 300 µg/L, 900 µg/L) in three exposure times (days 0, 13/14 and 26/27), and  we found that different iron concentrations did not affect algal palatability, bus we  observe higher consume in the middle exposure time, likely due to balance between  chemical defenses and algal integrity. Thus, we explored coral-algal interactions,  evidencing some global patterns and describing regional patterns that challenge  current paradigms in ecology that herbivory is the main factor mediating coral-algal  interactions.

5
  • MARIA NOEL CLERICI HIRSCHFELD
  • Knowledge and Power in Ecology and Conservation: analysis of the historical structures of knowledge and proposals for disciplinary integration towards a plural science

  • Advisor : CARLOS ROBERTO SORENSEN DUTRA DA FONSECA
  • COMMITTEE MEMBERS :
  • PABLO ALEJANDRO BRAZEIRO RODRÍGUEZ
  • RODRIGO FELIPE RODRIGUES DO CARMO
  • LUIZ ROBERTO RIBEIRO FARIA JUNIOR
  • CARLOS ROBERTO SORENSEN DUTRA DA FONSECA
  • CRISTINA BALDAUF
  • THOMAS MICHAEL LEWINSOHN
  • Data: Mar 27, 2024


  • Show Abstract
  • Ecology and conservation are disciplines that have changed in response to the social transformations and environmental conflicts we are experiencing. This thesis is the result of reflections on the construction of science as a space of power that is influenced by the historical, political and social context it experiences. The general aim is to conduct a critical analysis of the construction of knowledge in ecology and conservation based on the History and Sociology of Science and to propose new paths for building a plural science. Specifically, we seek to: (i) understand the relationship between knowledge and power in the scientific field, from a perspective situated in the South, (ii) advance integration between the social and natural sciences, and (iii) propose ways of overcoming historical inequalities in order to diversify science and pluralize knowledge. To this purpose, in chapter 1 we critically reflect on the historical and social dimension of ecology from the point of view of the social studies of science, seeking to move forward from the discussion around the object of ecology to placing ecology under the academic magnifying glass. In chapter 2, we critically reflect on recent proposals involving (de)coloniality in ecology and discuss the need to recognize and use theories produced in the Global South. In Chapter 3, we propose the Ecology of Absences as a theoretical-methodological tool for building a plural science. Chapter 4 aims to understand the construction and evolution of knowledge in the scientific field of Ecology, through the study of conceptual and collaborative networks, comparing Tropical Ecology and Temperate Ecology. In chapter 5, we defend the understanding of biodiversity conservation in the context of historical-sociological and local-global relations through World System Theory, initially proposed in the field of social sciences, and we apply this framework to the analysis of the COVID-19 pandemic as a case study, arguing that it must be understood as an emerging phenomenon of the society-nature dynamic of the world system. Finally, in chapter 6 we analyze the power relations linked to conservation research and practice, and argue in favor of a Critical Conservation Science. We argue that criticism as a tool for analyzing reality is fundamental in the field of conservation, in the face of a reality that is in constant movement. We build our argument on the principles of the Frankfurt School and Latin American critical theory.

2023
Dissertations
1
  • LIVIA VIEIRA CAVALCANTI
  • CONSERVATION IN PRIVATE PROTECTED AREAS: INFLUENCES OF SOCIAL AND POLITICAL FACTORS ON THE DYNAMICS OF CREATION OF PRIVATE RESERVES

  • Advisor : EDUARDO MARTINS VENTICINQUE
  • COMMITTEE MEMBERS :
  • ADRIANA MONTEIRO DE ALMEIDA
  • CARLOS ROBERTO SORENSEN DUTRA DA FONSECA
  • EDUARDO MARTINS VENTICINQUE
  • MARINA ANTONGIOVANNI DA FONSECA
  • Data: Feb 27, 2023


  • Show Abstract
  • The preservation of biodiversity and the provision of ecosystem services increasingly depend on environmental conservation on private lands. There are many studies demonstrating the capacity of private protected areas to conserve biodiversity. Private conservation has been growing globally, but its management characteristics levels of use and protection differ between countries. Despite these differences, these areas have in common the role of important actors involved in financing and promoting actions for environmental protection. Our aim is to understand possible political and social context factors, in the national and regional scenario, that contributed to the dynamics of creation of Brazilian Private Natural Heritage Reserves (RPPNs). We applied an online questionnaire to owners and managers, collected and analysed data focusing on motivations, difficulties, support received and actors involved in the process of creating RPPNs. Our results showed that around 70% of the owners' motivations were mainly conservationist, although not exclusively so. This was a pattern, independent of region or biome, scope of creation (federal, state or municipal) or type of owner (individual or company). With regard to difficulties, 58% experienced difficulties, regardless of time, the majority of which were bureaucratic (75%), differing between region and biome. Only 57% of landowners received support, 67% from Non-Governmental Organizations and 31% from state governments. For landowners, technical support was more significant than financial support. The creation of RPPNs can be attributed not only to laws or specific policies to encourage it, but also to the altruism of the landowners. The social interactions existing in a region or within a group of people seem to have determined the dynamics. Legislation enacted at different levels of government in combination with socio-economic trends create the conditions for establishing RPPNs. Projects and public notices encouraging the creation of new RPPNs, with the predominant participation of NGOs, were crucial to the emergence of new RPPNs.

2
  • JAQUELINE SILVA MOURA
  • ECOLOGICAL INTERACTIONS AND ABIOTIC CHARACTERISTIC INFLUENCE THE SUCCESS OF CAATINGA FOREST RESTORATION.

  • Advisor : GISLENE MARIA DA SILVA GANADE
  • COMMITTEE MEMBERS :
  • WANESSA NEPOMUCENO FERREIRA
  • CARLOS ROBERTO SORENSEN DUTRA DA FONSECA
  • GISLENE MARIA DA SILVA GANADE
  • Data: Feb 28, 2023


  • Show Abstract
  • Several ecological processes can influence the structure and dynamics of communities to be restored. Among them are abiotic interactions such as facilitation, competition, and mycorrhizal symbiosis, as well as system limiting factors. In Caatinga, a seasonally dry Brazilian forest, little is known about how these interactions can contribute to the success of both the production of seedlings in the greenhouse and to increase their survival and performance in the field. To answer these questions, this dissertation is divided into two chapters, in the first, we tested how the addition of co-species tree soil (inoculum soil) containing Arbuscular Mycorrhizal Fungi (AMF) spores can improve seedling production of 7 potential tree species for ecological restoration of the Caatinga. The results showed that AMFs positively influenced the growth of most tree species, however the species responded differently to the growth parameters. We also found that the trees that showed the highest richness of AMFs were also the ones that showed the best performance in development and showed little similar AMF species, demonstrating that the positive effect on plants was more dependent on richness than on composition. These results highlight that the application of inoculum soil with native AMFs may be an efficient and low-cost approach to increase seedling performance and consequently overall success rates of dryland ecosystem restoration. In the second chapter, we tested in an in situ experiment, how facilitating herbaceous and arboreal plants, Arbuscular Mycorrhizal Fungi and limiting abiotic factor (water), influence the survival and performance of seven tree species (target species). To this end, we implemented an experiment with factorial combinations of presence and absence of the following treatments replicated 5 times each: mycorrhiza (symbiosis); tree facilitator (facilitation); competitive herbaceous (competition); and water (abiotic limiting factor). Multifactorial anovas demonstrated that the limiting factor is able to modulate facilitation and competition interactions during restoration. The addition of water at the time of planting contributed to both facilitating and competitive herbaceous plants having a positive influence on growth measures of the target species, however the benefits were neutralized when the two groups of plants co-occurred. We also evidenced that in the absence of water, facilitating and/or herbaceous plants compete for resources more intensely, suppressing the growth of the target species. Thus, for best results, restoration projects must reconcile the management of competitive facilitators or herbaceous plants with the addition of water; if irrigation during transplanting is not possible, the use of only the target plant is the most indicated. We found that the outcome of the interactions may be dependent not only on resource availability, but also on the tolerance and competitive ability of the target species, thus future studies should investigate which combinations of techniques are best suited for the various species. Finally, we found that management of mycorrhizal fungi with facilitators can bring greater benefits to some species in the presence of water, however, the absence of water implies greater competition for resources, in the latter case, it is recommended to use only the facilitator species for greater benefits. In summary, this work contributes to the advancement of new techniques that can substantially increase the success of restoration in the Caatinga and other semi-arid regions.

3
  • MARIA LUÍSA DE MEDEIROS FALCÃO
  • SHIFTS IN MAMMALS ACTIVITY PATTERNS IN RESPECT OF DAILY AND ANNUAL CHANGE IN CLIMATE CONDITIONS IN THE CAATINGA

  • Advisor : EDUARDO MARTINS VENTICINQUE
  • COMMITTEE MEMBERS :
  • EDUARDO MARTINS VENTICINQUE
  • ARIOVALDO PEREIRA DA CRUZ NETO
  • CECILIA IRENE PEREZ CALABUIG
  • Data: Mar 31, 2023


  • Show Abstract
  • The Brazilian seasonally dry tropical forest (Caatinga) is a semi-arid environment marked by a long dry period and a short rainy period that results in a great fluctuation in the conditions and resources for fauna. Medium to large mammals are usually the group most threatened by human activities, and thus are considered indicators of biotic integrity of the environment. Thus, understanding their ecology is essential for the effectiveness of management and conservation strategies, especially within protected areas, which, despite being the main strategy used for the persistence of biodiversity, are still scarce in the Caatinga. The objective of this work was to investigate the ecology of the mammal community in Furna Feia National Park, and how seasonality influences the ecology parameters of the community and the species. More precisely, we characterized the richness, frequency of records, composition, simple occupancy and activity pattern of the species and their relationship with seasonality. We collected the data throughout the rainy and dry seasons of 2018, using camera traps at 44 and 40 sampling points, with an effort of 2267 and 1639 camera-days, respectively. Rarefaction curves, circular statistics, and occupancy models were some of the analyses used to characterize the community and its seasonal patterns. We obtained 485 records of 11 species of mammals distributed in six orders and nine families, including two species threatened with extinction in Brazil and/or by the IUCN (Leopardus emiliae and Herpailurus yagouaroundi) and the first photographic record of free-living Dicotyles tajacu for Rio Grande do Norte. Species with the highest frequency of records include Subulo gouazoubira, Euphractus sexcinctus and Sapajus libidinosus. Meanwhile, Leopardus pardalis, H. yagouaroundi and D. tajacu were the least recorded. Regarding the activity pattern, S. gouazoubira changed from the rainy to the dry season, from diurnal to nocturnal. While the other species analyzed seem to distribute their activities to avoid the hottest times of the day, especially during the drought. The species richness did not change, but relative abundance was higher in the wet than in the dry season for most species, except for D. albiventris, which showed the opposite trend. Some species exhibited no variation in occupancy and detectability, while others such as S. gouazoubira were more detected and expanded their occupancy in the wet season. This work represents the first systematic survey with camera trap for an important UC in the Caatinga, and the results on seasonal and circadian activity rhythm will improve the understanding of animal ecology and the mechanism of permanence in seasonally dry environments.

4
  • WILDNA FERNANDES DO NASCIMENTO
  • Mass coral bleaching in shallow reefs of Northeast Brazil following a major heatwave

  • Advisor : GUILHERME ORTIGARA LONGO
  • COMMITTEE MEMBERS :
  • AMANA GUEDES GARRIDO
  • GUILHERME ORTIGARA LONGO
  • MIGUEL MIES
  • Data: Apr 24, 2023


  • Show Abstract
  • Marine heat waves are becoming more frequent and intense due to global climate change, and are considered one of the major causes of reef degradation. Coral reefs in the Southwest Atlantic have experienced fewer heat wave events compared to the Indo-Pacific and Caribbean, but this scenario has changed in the last decade as the region has been hit by some bleaching events. In 2020, the northeast Brazilian was affected by one of the biggest heat waves in recent years, causing bleaching event never seen before in the region reaching 16.86°C-weeks, the highest value since records began in 1985. health of corals from December 2019 to January 2021, in the reefs of Rio do Fogo - RN. Our goal is to understand whether the impacts caused by the heat wave vary between coral species and are influenced by morphological attributes such as colony size. We assessed coral health using the Coral Watch Coral Health Chart through photo-squares along 5 transects. We evaluated the health of the stony corals Agaricia agaricites, Favia gravida, Porites astreoides, Siderastrea stellata and the zoanthids Palythoa caribaeorum, Palythoa grandiflora, Palythoa variabilis and Zoanthus sociatus. We observed that the stony corals showed a high level of bleaching when the heat wave was at its highest (April and May) and the species P. astreoides and S. stellata were able to recover their healthy color in about two months. The opposite was observed for A. agaricites and F. gravida, which presented coverage losses of 100% and 90% respectively. In the case of zoanthids, the species remained stable. We observed that small colonies (< 5cm²) of S. stellata (dominant coral) showed greater sensitivity to the heat event, bleaching before larger colonies. In the period when the heat wave was most severe, more than 85% of the number of colonies of all classes showed signs of bleaching, with a decline in this value after the fall in Degree Heating Weeks (DHW). Thus, coral species should remain stable after bleaching events, although less abundant species have not recovered, which can cause loss of coral diversity, threatening the coral fauna that is highly endemic in these areas.

5
  • MARIANA SELL DE MIRANDA FERRAZ
  • Rethinking fisheries management: the role of local ecological knowledge in stimulating community participation

  • Advisor : PRISCILA FABIANA MACEDO LOPES
  • COMMITTEE MEMBERS :
  • NIDIA NOEMI FABRÉ
  • PRISCILA FABIANA MACEDO LOPES
  • RENATO AZEVEDO MATIAS SILVANO
  • Data: May 26, 2023


  • Show Abstract
  • Co-management is a system of resource governance characterized by the participation of local stakeholders in decision-making processes. Several factors affect resource users participation in management, such as material assets, education, active involvement in management, and participation in community associations. A case study was conducted based on the reconstruction of past fishing catches from fishermen&#39;s memories, in order to discuss the potentials and limitations of using scientific knowledge and local ecological knowledge. This chapter aims to understand if the type of knowledge (traditional or scientific) influences the fishermen&#39;s participation in the co-management process. It is expected that fishermen prefer the use of their own knowledge, associated or not with scientific knowledge, rather than the exclusive use of scientific knowledge. The fishery reconstruction was developed using data from four fisheries, three located in the northeast (Rio Grande do Norte) and focused on the capture of Lutjanus analis (cioba), Coryphaena hippurus (dourado), and Opisthonema oglinum (sardinha), and one located in the southeast (Rio de Janeiro), focused on the capture of Mugil liza (tainha). A total of 131 interviews were conducted in the Ponta do Tubarão State Sustainable Development Reserve (RDSEPT/RN) and 74 in Araruama (RJ) using a semi-structured  questionnaire. The questionnaire was used to estimate the catch of the species for the last five decades and to assess the level of fishermen&#39;s participation in fisheries management. The decline in the average catch of dolphinfish and sardine between 1980 and 2020 was observed, as well as in the total catch of mullet between 1970 and 2020. In addition, most of the fishermen interviewed expressed that they prefer management decision making to be based on a combination of scientific knowledge and local ecological knowledge. The analysis of the results of this case study makes it possible to identify the main benefits and limitations of using scientific knowledge and local ecological knowledge in the management process. 

6
  • FRANCISCO WALISON DOS SANTOS MACHI
  • Occupation of the Species Euphractus sexcinctus (square armadillo) and Dasypus novemcinctus (banded armadillo) in the semiarid region of northeastern Brazil.

  • Advisor : EDUARDO MARTINS VENTICINQUE
  • COMMITTEE MEMBERS :
  • EDUARDO MARTINS VENTICINQUE
  • MAURO PICHORIM
  • MARINA ANTONGIOVANNI DA FONSECA
  • Data: Jul 19, 2023


  • Show Abstract
  • The Caatinga is a well-recognized ecological region found in the semi-arid interior of northeastern Brazil. The dominant vegetation type in the region is a seasonally dry tropical forest. As in any other semi-arid region, the Caatinga has a prolonged dry period in which rainfall is scarce. It is the only ecosystem with geographic limits restricted to the Brazilian territory and presents a great contribution to biodiversity. In this sense, studies are needed to understand the use and occupation of habitats by species of mammals in this biome. Thus, we highlight the main group of burrowing mammals in the Neotropical region, the armadillos. As the focus of this research, we restricted to two species, the Euphractus sexcinctus (square armadillo) and Dasypus novemcinctus (square armadillo), as well as other species of armadillos, whose conservation is threatened by anthropic action, specifically hunting and the degradation of its habitat. habitat, despite these factors, are not considered endangered species. It is also worth noting that studies on the large and medium-sized mastofauna in the Caatinga are still insufficient to understand patterns of occupation of the species. This research is divided into a chapter, where in CAP 01 – we observe the effect of environmental and anthropic factors on the occupation of Euphractus sexcinctus (armadillo) and Dasypus novemcinctus (armadillo) in areas of Caatinga. A total of 928 photographic records of armadillos were obtained. Being 810 of E. sexcinctus and 118 of D. novemcinctus. While E. sexcicnctus presented a distribution of records in all areas, the same did not occur for D. novemcinctus, which had 94% of its occurrences in Bahia and occurred only in one area in Rio Grande do Norte, which was the region of Lajes.

7
  • LEONARDO CRUZ DE SOUZA
  • Fewer countries reap the benefits of a future ocean

  • Advisor : PRISCILA FABIANA MACEDO LOPES
  • COMMITTEE MEMBERS :
  • ANDROS TAROUCO GIANUCA
  • KEMAL ALI GER
  • PAUL GERHARD KINAS
  • PRISCILA FABIANA MACEDO LOPES
  • Data: Nov 20, 2023


  • Show Abstract
  • Climate change-induced redistribution of fish stocks is anticipated to have global implications for marine fisheries. For instance, it is expected that fish catch potential will increase in higher latitudes, while declining in tropical regions. However, how different countries and fishing gears will respond, and whether they will be able to redistribute their catches spatially in response to these changes remains unknown. We built fisheries distribution models and projected their occurrence globally, across 82 countries and 13 fishing gears in 2100, under two climate scenarios: the low and high levels of greenhouse gas emissions. Globally, fisheries occurrence is expected to significantly increase at the poles, whereas vulnerable fishing-dependent tropical regions like the Indo-Pacific and Western Africa are projected to experience significant declines. We also show that countries already engaged in polar fishing are likely to be the primary beneficiaries of the newly available and favorable fishing grounds, with eventual benefits of climate change being limited to a select few nations, resulting in both winners and losers. East Asian and Pacific nations with fleets predominantly composed of drifting longlines experienced negative impacts, whereas European countries equipped with trawlers and other polar gears reaped benefits. Our findings emphasize the importance of prioritizing the low-emission scenario to reduce the increasing disparities in the future of marine fisheries, given that changes in occurrence were more than twice as high under the high-emission scenario.

Thesis
1
  • AUGUSTO CÉSAR DA SILVA
  • Biogeographical Patterns and Ecological Strategies in the Caatinga Domain and the Brazilian Dry Diagonal


  • Advisor : ALEXANDRE FADIGAS DE SOUZA
  • COMMITTEE MEMBERS :
  • ALEXANDRE FADIGAS DE SOUZA
  • ALICE DE MORAES CALVENTE
  • ANGELA PIERRE VITÓRIA
  • GISLENE MARIA DA SILVA GANADE
  • SERGIO DE FARIA LOPES
  • Data: Feb 16, 2023


  • Show Abstract
  • Despite the growing knowledge about the distribution and functioning of vegetation in seasonally dry environments, its internal structure and the organization of its functional attributes are still poorly understood. The objectives of each chapter of this Thesis were 1) to delineate the compositional sub-regions in the Caatinga domain, considering the species abundances, and evaluating the determinants of their spatial distribution, 2) to identify the functional strategies of the species in the Caatinga within the scope of CSR theory and global functional spectrum, and 3) identify how current or historical environmental and human filters determine the structuring of functional attributes in the Brazilian dry diagonal (Caatinga-Cerrado-Pantanal).For the first chapter, subregions were identified and mapped, partitioning interpolated NMDS ordering axes using the K-means method. We used a selection of GLM models to identify the set of variables that explained bias across subregions. For the second chapter, the classification of ecological strategies using species functional data (leaf area, leaf dry matter content, leaf nitrogen, leaf mass per area, wood density and potential plant height) were used to calculate the CSR and functional space for Caatinga. We used the StratFY matrix and a phylogenetic PCA to generate CSR strategies and functional correlations. For the third chapter, an extended RLQ analysis was used to identify the relationship of attributes and their respective environmental and human filters. . For the first chapter, the K-means analysis identified 10 sub-regions. The combined fractions of aridity, topography and soil, stability of the biome in the Pleistocene and the historical effect of indigenous activities explain most of the variability in the subregions. For the second chapter, the strategies of the species in the caatinga are mostly concentrated in the competitor-stressor space of the CSR triangle. The first two pPCA axes explain 76% of the attribute variation, reflecting in two main functional groups in the Caatinga. For the third chapter, the RLQ indicated the presence of two functional gradients related to categorical attributes of the leaf and fruit filtered by the combination of soil, topography, and current and historical human factors. The spatial structuring patterns of abundance and their functional strategies are an important contribution to understanding the action of environmental filters and functional strategies of species in seasonally dry environments, the results presented here can support important decisions in conservation and management in these environments.

2
  • MAIARA MENEZES
  • PRESENCE AND EFFECTS OF PLASTIC POLLUTION ON MARINE AND FRESHWATER FISH

  • Advisor : JULIANA DEO DIAS
  • COMMITTEE MEMBERS :
  • JULIANA DEO DIAS
  • JOSE LUIZ DE ATTAYDE
  • LUÍS GABRIEL ANTÃO BARBOZA
  • MARIO BARLETTA
  • ROBSON GUIMARÃES DOS SANTOS
  • Data: May 30, 2023


  • Show Abstract
  • The increase in plastic production and consumption in recent decades has been accompanied by a proportional increase in its disposal and accumulation in the environment, particularly in its potentially most polluting form, the microplastic (particles &lt;5mm). The presence of this emerging pollutant in the environment invariably results in its interaction with organisms, potentially generating multiple effects on wildlife and human health. The scientific community has invested significant efforts to better understand such effects. However, some aspects are still unclear, while others are underexplored, especially at broader ecological scales involving ecosystem approaches and multiple levels of biological organization simultaneously. Studies in this context offer necessary advances to roaden the understanding of the threat of plastic pollution. Therefore, this thesis is organized into three chapters that investigate the plastic contamination in aquatic organisms, using fish as model organisms, and evaluate the potential effects of this contamination on physiological, functional and ecological aspects. Additionally, we will address the issue of food security, related to human consumption of potentially microplastic-contaminated marine species. In the first chapter, we tested whether exposure to microplastic can affect the health and performance of freshwater fishes, assessing biological factors from molecular to organismal level. In the second chapter, we conducted an in-situ experiment to test whether the presence of plastic in the environment influences the herbivory pressure of reef fishes, and consequently, their ecosystem function. And in the third chapter, we seek to estimate the degree of contamination in commercially relevant species in NE Brazil in order to point out the ecological and socioeconomic impacts of plastic pollution. With this thesis, we hope to contribute to the construction of a broader and more solid foundation regarding the impacts of plastic and microplastic on aquatic organisms and ecosystems.

3
  • WAGNER DE FRANCA ALVES
  • SPATIAL PATTERNS OF BIODIVERSITY AND STABILITY ALONG URBANIZATION AND LAND USE GRADIENTS



  • Advisor : ANDROS TAROUCO GIANUCA
  • COMMITTEE MEMBERS :
  • ANDROS TAROUCO GIANUCA
  • ADRIANO CALIMAN FERREIRA DA SILVA
  • GISLENE MARIA DA SILVA GANADE
  • DUARTE DE SERPA PIMENTEL TEIXEIRA
  • VINÍCIUS AUGUSTO GALVÃO BASTAZINI
  • Data: Jun 22, 2023


  • Show Abstract
  • Growing anthropogenic pressures on earth, particularly those related to urbanization and agricultural intensification, have resulted in the loss and fragmentation of habitats, with possible consequences for biodiversity and ecosystem stability. However, there is still limited understanding of how different taxonomic groups respond to these pressures and at what spatial scale these effects are strongest. Another uncertainty concerns the level of spatiotemporal change of the different dimensions of biodiversity (e.g., taxonomic and functional). The main goal of this thesis is to evaluate how anthropic impacts affect species diversity and stability patterns at multiple spatial scales. For that, we used databases of hundreds of animal metacommunities, collected with high spatial and temporal resolution and through international collaborations from several European countries. This thesis is divided into three chapters. In the first, we assess how different facets of diversity and abiotic factors affect the stability of butterflies’ abundance at multiple scales. For this, we used species abundance data collected during a minimum of four and a maximum of twelve years and integrated with functional attributes of butterflies in seven European countries. Our results provide the first evidence that both local stability and community asynchronous dynamics drive regional stability of butterfly abundance, but with relatively greater importance of the former component. We found that climatic factors (temperature and precipitation) and spatial distance modulated the stabilizing effect of different facets of biodiversity, mainly in a positive way. Overall, we found that taxonomic α-diversity and functional β-diversity were important drivers of maintaining regional stability. We also demonstrate that there is a relative change in the contribution of local and regional stabilizing processes depending on the dispersal ability of butterflies. Particularly, species with low dispersal capacity have higher functional β-diversity and metapopulational and spatial asynchrony, which contributes to regional stability. On the other hand, communities of species with high dispersal capacity present greater α-diversity (taxonomic and functional), which results in a stronger contribution of local mechanisms on the stability of metacommunities. In the second chapter, we use the same data of butterflies to assess the prevalence of biotic homogenization and differentiation over 12 years in Europe and relate these patterns to various functional attributes of butterflies. We found an increase in the proportion of species with greater thermal tolerance and egg volume in most metacommunities, regardless of taxonomic and functional homogenization or differentiation scenarios. Finally, in the third chapter, we investigate how the relationships between dispersal ability and body size of six groups of arthropods influence the relative amount of β-diversity components: species replacement and nestedness (variation in species composition resulting from difference of species richness between communities). For this type of analysis, urban gradients were considered, which were quantified at multiple spatial scales. We found that groups with a positive relationship between body size and dispersal ability showed a more pronounced nestedness pattern towards urban centers compared to groups that showed a neutral relationship between size and dispersal ability, mainly at the local scale. This result is in agreement with our hypotheses and indicates that not only is size an important attribute that influences species selection along the urban gradient, but that variation in dispersal capacity also influences the organization of urban metacommunities, implying different regional management strategies. Overall, our results indicate that (i) mobility changes the relative importance of local and regional stabilizing processes; (ii) the trend observed for species with broad climatic tolerance and larger egg size, considering the different homogenization and differentiation scenarios, suggests that climatic extremes seem to be the strongest filter in the structuring of butterfly communities and that larger egg size may be associated with factors that positively influence larval survival and (iii) structural and functional connectivity modulates the responses of taxa to environmental disturbances. Furthermore, we emphasize the necessary consideration of multiple spatial scales to improve understanding of biodiversity change along disturbance gradients and their stabilizing effect, with direct implications for conservation and management.

4
  • THAYNÁ JEREMIAS MELLO
  • Local and global impacts on the reefs of Fernando de Noronha Archipelago

  • Advisor : GUILHERME ORTIGARA LONGO
  • COMMITTEE MEMBERS :
  • CARLOS EDUARDO LEITE FERREIRA
  • Fabian Sá
  • GUILHERME ORTIGARA LONGO
  • MARIA CHRISTINA BARBOSA DE ARAUJO
  • VINICIUS JOSÉ GIGLIO FERNANDES
  • Data: Aug 28, 2023


  • Show Abstract
  • Reefs and other marine ecosystems face significant threats from human impacts, including pollution, poorly regulated tourism and global climate change. Marine Protected Areas (MPAs) stand out among the most important strategies for marine conservation. In Brazil, the Fernando de Noronha archipelago (FN) is protected by two MPAs: a no-take area and a multiple-use area. However, the archipelago has been experiencing increasing impacts due to the expansion of tourism and human occupation, and climate change. In this context, the main objective of this thesis was to assess the 

    role of MPAs in mitigating multiple local and global impacts on marine environments in FN. In Chapter 1, we investigated the presence of marine litter on the beaches of FN and its distribution related to oceanographic factors and tourism. We found a higher abundance of plastics in uninhabited areas on the windward side, despite being within the no-take area, a more restricted MPA, while on the leeward coast, near urban areas and within a less restricted MPA, there were more disposable plastics and cigarette butts. In Chapter 2, we investigated the temporal dynamics of benthic organisms in a tide pool and observed that temperature anomalies were the main factor affecting coral health and their endosymbiont communities. Although seasonal burial caused high temporal variability in benthic cover, it did not affect coral health. The number of tourists diving in the area also did not influence coral health, indicating that proper management can reduce tourism impacts. In Chapter 3, we mapped and quantified marine pollution in FN (nutrients, metals, microplastics, sterols, and polycyclic aromatic hydrocarbons - PAHs), characterizing their sources and evaluating their impacts on reef communities. We detected pollutants both in the multiple-use and in the no-take area. While nutrient concentrations in the water were in accordance with legislation in most samples, effluents from wastewater treatment plants did not meet legal standards. The isotopic signature of macroalgae indicated the presence of sewage-derived nitrogen throughout the multiple-use area, and nutrient-enriched areas showed distinct benthic communities with higher algal biomass. Sediment analysis revealed generally low levels of PAHs and fecal sterols, except in samples from Porto. We observed relatively high metal concentrations in sediments at some sampling stations, which may be related to both anthropogenic sources and the volcanic origin of the archipelago. Microplastics were found in all sediment and water samples, from the multiple-use and the no-take area. We emphasize the urgent need to improve wastewater management to protect the marine ecosystem in FN, promoting its resilience facing climate change. We also highlight the vulnerability of the no-take area, with pollutants originating from the multiple-use area on the leeward coast and pollutants transported by currents from distant sources on the windward coast. The information generated by this work will serve as an important reference for monitoring initiatives and improving management strategies for conserving FN and other MPAs.

5
  • CARLOS ALBERTO NASCIMENTO DA ROCHA JUNIOR
  • SYSTEMIC ANALYSIS OF LAKE ENVIRONMENTS IN THE TROPICAL SEMIARID: SUPPORT FOR EUTROPHICATION
    MANAGEMENT AND MITIGATION PROJECTS

  • Advisor : VANESSA BECKER
  • COMMITTEE MEMBERS :
  • VANESSA BECKER
  • JOSE LUIZ DE ATTAYDE
  • RENATA DE FÁTIMA PANOSSO
  • FABIANA OLIVEIRA DE ARAUJO SILVA
  • IRAN EDUARDO LIMA NETO
  • ROSEMBERG FERNANDES DE MENEZES
  • Data: Aug 30, 2023


  • Show Abstract
  • Eutrophication is considered one of the main water quality problems in lake ecosystems today, leading to losses of important ecosystem goods and services, as well as consequences of reduction and reduction of biodiversity. Eutrophication is the result of the input of nutrients transported to aquatic ecosystems, which are later deposited in the system. The selection of eutrophication management and mitigation measures requires an adequate systemic (diagnostic) analysis of each lake. In addition, semi-arid aquatic ecosystems are among one of the most independent systems to eutrophication. The general objective of this thesis was to provide information to support projects for the management and mitigation of eutrophic environments in the tropical semi-arid region, through integrated systemic analysis involving water quality, in addition to the analysis of phosphorus sources and fluxes. Chapter 1 addressed the temporal dynamics and a diagnosis of water quality in a semi-arid tropical reservoir used for multiple uses. The results show the process of degradation of the reservoir's environmental health over prolonged periods, being intensified by a period of prolonged drought, causing a reduction in the stored water volume, also favoring characteristics of a shallow and mixed environment with dominance of cyanobacteria. Characteristics such as the absence of background anoxia events, high concentrations of humic substances and high pH can make certain mitigation measures and strategies unfeasible. Chapter 2 analyzed land use and occupation and its influence on the spatial distribution of mobile forms of phosphorus in the sediment. The focus of this chapter was to quantify the potential sources of eutrophication, external and internal. Thus, the results of the chapter showed the anthropic activities along the drainage basin and area of influence, and its potential contribution of mobile phosphorus present in the sediment, which is spatially distributed in a heterogeneous way along the reservoir. These results point to agriculture, livestock and floodplain vegetation as priority activities and coverage for proper management, in addition to the preservation of the riparian zone. Chapter 3 showed a temporal analysis of the mass balance, using a P load estimation model, as well as evaluating the effects of this load on water quality. The results of the chapter showed a high and constant internal phosphorus load due to a reduction in the volume of stored water and susceptibility to the action of winds for resuspension of nutrients. In addition, there is evidence of a delay in the reduction of internal loads, which may continue to intensify the eutrophication phenomenon even with the reduction of external loads. The results of this thesis emphasize that the management and mitigation of eutrophic environments in this region is still deficient, as evidenced  hroughout this thesis cause the intensification of the effects of eutrophication on thewater quality of the reservoirs. Finally, this thesis represents an important systemic analysis, and this methodology can serve as a reflection for reserves in the world and support the choice of strategic management measures for the recovery of eutrophicenvironments in the semi-arid region. 

2022
Dissertations
1
  • PRISCILLA EVELYN DE SOUZA SILVEIRA
  • Factors affecting the molt patterns of feathers in Passerines in the far northern Atlantic Rainforest.

  • Advisor : MAURO PICHORIM
  • COMMITTEE MEMBERS :
  • MÁRCIO AMORIM EFE
  • JOÃO PAULO TAVARES DAMASCENO
  • MAURO PICHORIM
  • MIRIAM PLAZA PINTO
  • Data: Feb 21, 2022


  • Show Abstract
  • Feather molt in birds is a naturally occurring process due to the wearing down of old feathers. For it to occur, a large amount of energy is required, so it does not usually coincide with other events in the bird's life cycle such as breeding and migration. It is common for the moulting period to occur at a time of year when there is a greater supply of food. Factors such as primary productivity of the region and rainfall can directly affect resource availability. The Passerine order is the largest order of the bird group, and several ornithological studies are carried out with representatives of this group due to its great diversity. Our study was carried out with passerines from a restinga area, typical vegetation of the Atlantic Rainforest, which houses peculiar vegetation formations and little is known about its avifauna. Based on this, we sought to understand whether there is overlap between the moulting period and breeding, and whether there are differences in the moulting patterns due to differences in the diets of these passerines. We used a database of bird captures at CLBI, Parnamirim, RN formed between 2010 and 2014. We counted presence or absence of wing, tail, body and simultaneous wing, tail and body moulting. We also counted presence or absence of brood patch. We separated the species into four diet groups: fruit, invertebrate, invertebrate/fruit, and omnivorous. We ran GLM models to analyze which variable best explained the variation in moult frequency, and simple linear regressions to analyze the relationship between moulting and the variables studied. Our results showed that the best variable that explained the variation in moult frequency was NDVI, as a temporal variable, and the moult frequency was different between flight feathers (rems and retrizes) and body feathers, with these types of moults configuring the most explanatory biological variable. We also saw that the different diets did not influence the frequency of moulting, and that the weak overlap found between the moulting period and reproduction occurs only as a temporal coincidence, since the peak of reproduction occurs in February and the peak of the moulting period occurs in May.

2
  • LAIANE LANE LUCENA DE MEDEIROS
  • Influence of macroalgae on the trophic web of coastal environments impacted by fisheries


  • Advisor : FULVIO AURELIO DE MORAIS FREIRE
  • COMMITTEE MEMBERS :
  • ALEX SOUZA LIRA
  • FULVIO AURELIO DE MORAIS FREIRE
  • Maria Alice Leite Lima
  • Data: Feb 22, 2022


  • Show Abstract
  • Coastal environments are often being degraded as a result of anthropogenic impacts. The bloom of macroalgae is a consequence of eutrophication of water bodies, through bottom-up regulation, which can favor herbivorous organisms, detritivores, and filter feeders, increasing gross primary productivity and respiration of ecosystems. Similarly, fisheries overexploitation can act in top-down regulation, favoring macroalgal blooms via declines in top predatory fish. In order to understand the complexity of trophic webs in coastal ecosystems impacted by macroalgae and fishing activity, we used the software Ecopath with Ecosim. For this, two coastal environments, exploited by artisanal fishermen, were evaluated, and compared: Baía Formosa (BF) and Porto do Mangue (PM) (environment influenced by macroalgae blooms), both in Rio Grande do Norte state, northeastern Brazil. The high nutrient concentration added to the semi-arid conditions of PM favored a higher biomass of Primary Producers (Macroalgae and Phytoplankton) and mesopredator fishes in this ecosystem. BF, on the other hand, showed higher biomass of invertebrates, favored by the low algal biomass and finer sediment of this ecosystem, composed of silt and clay, and enriched by organic matter, and top predatory Fishes. Such structural characteristics of PM resulted in high Net Primary Production and flow diagram based on bottom-up regulation. However, macroalgae showed low trophic impact, since much of their biomass was transformed into detritus and exported to adjacent ecosystems, which characterized it as an immature ecosystem. The opposite was found in the BF ecosystem, considered mature, with a high flow of consumption, respiration, and also a high representation of all trophic levels in its flow chart. Fishing, in turn, did not favor macroalgae blooms, but differentially affected the other compartments between the ecosystems. In BF, the capture specialized in top predators favored fish of intermediate trophic levels. In PM, fishing had a detrimental effect along the web, because the catch was generalized, negatively impacting the various trophic levels. Therefore, eutrophication and fishing activity in PM generated greater stress for the species that make up the trophic web of this ecosystem, hindering the evolution towards a more stable and mature state of ecological succession.

3
  • RAIANE VITAL DA PAZ
  • Assessing scale-dependent effects of urbanization on avian diversity.

  • Advisor : ANDROS TAROUCO GIANUCA
  • COMMITTEE MEMBERS :
  • ANDROS TAROUCO GIANUCA
  • EDUARDO MARTINS VENTICINQUE
  • GUILHERME SANTOS TOLEDO DE LIMA
  • JEFERSON VIZENTIN-BUGONI
  • Data: Feb 23, 2022


  • Show Abstract
  • Urbanization is a major driver of natural habitat reduction and fragmentation, and it has been shown that these impacts can influence species richness. However, how different components of diversity are influenced by urban intensity, patch size, and isolation between patches has not yet been mechanistically investigated. In this context, urbanization gradients are ideal for assessing how species respond to these impacts, and also allow us to better understand how local and regional changes in habitat quality influence diversity components such as: species abundance distribution (SAD), total community abundance (N), and intraspecific spatial aggregation (Agg). Here, we evaluate how two different categories of urbanization intensity (urban squares and protected areas), patch size, and its connectivity influence bird diversity patterns at various scales. To assess scale-dependent processes, 24 plots were allocated, each subdivided into 4 subplots, totaling 96 points, which were visited five times during the dry season. In these same plots/subplots local and regional environmental features were assessed. A significant reduction in species richness and abundance was observed with increasing urbanization, and this reduction was evident across all scales analyzed. However, the effect of urbanization was even stronger at plot than subplot scales, indicating a scale-dependent effect of urbanization. Furthermore, both local and regional variables, including vegetation cover and structural connectivity, were important determinants of bird diversity patterns. Thus, it is necessary to conduct practices that can reduce the intensive impact of urbanization. An example to be highlighted are actions that include more forested squares, as well as planting trees around these squares and forming ecological corridors, aiming to connect parks and green areas with urban squares.

4
  • TAMARA SANTOS
  • Spatial and temporal ecology of the canid Cerdocyon thous in a tropical dry forest: fragmentation, amount of habitat and chronic anthropogenic disturbance effects

  • Advisor : CARLOS ROBERTO SORENSEN DUTRA DA FONSECA
  • COMMITTEE MEMBERS :
  • CARLOS ROBERTO SORENSEN DUTRA DA FONSECA
  • FREDERICO GEMESIO LEMOS
  • RODRIGO LIMA MASSARA
  • Data: Feb 23, 2022


  • Show Abstract
  • Human activities have caused profound changes in natural landscapes, and it is essential to understand how the fauna responds to these changes. In this study, we tested the relative importance of habitat availability, fragmentation and chronic anthropogenic disturbance (CAD) on the abundance, occupation pattern and activity pattern of Cerdocyon thous, a generalist canid, in a tropical dry forest. Data were collected between May and September 2014 in 10 priority areas for conservation in the Caatinga of the state of Rio Grande do Norte. Altogether, there were 179 sampling sites and a sampling effort of 6,701 traps.day. Multiple regression models of occupancy and GLM were used to test how occupation and abundance of C. thous respond to explanatory variables: habitat availability, edge density, CAD, altitude and terrain roughness. Subsequently, an alternative model was tested, in which habitat availability was broken down into three natural habitats (forest, savannah and grassland), while the CAD was broken down into five vectors (human population, infrastructure, pasture, logging and fires). The results indicate that C. thouswas more abundant in more fragmented areas and with greater CAD. The species also occupied and was more abundant in areas closer to human density and with more pastures. Habitat availability negatively influenced occupation, but the species responded differently to types of habitats. The forest habitat had a negative effect on both occupation and abundance, while the savannah had a positive effect on abundance, however grassland was not a significant variable in any of the analyses. Apparently, the species benefits from the anthropization of the environments, but with a certain limit because it is also negatively affected. For the activity pattern, we used kernel density models, and evaluated the response of C. thous to sites with more and less: habitat availability, fragmentation and CAD. The activity pattern in the study area was crepuscular nocturnal, with two more marked activity peaks, one in the early morning and the other at night. Despite the high values of the overlap index for all variables tested, and no significant differences for most of the variables tested, there were differences in activity peaks for the variables: habitat availability, human population and pasture. Possibly, the species changes the activity peaks due to the use of human resources (agriculture or garbage, for example), due to the activity of a particular prey or to prevent competition.

5
  • FABRICIO CLAUDINO DE ALBUQUERQUE
  • Marine protected areas and Brazilian corals: what are we protecting?

  • Advisor : GUILHERME ORTIGARA LONGO
  • COMMITTEE MEMBERS :
  • GUILHERME ORTIGARA LONGO
  • HELOÍSA DANTAS BRUM
  • MARIANA BENDER GOMES
  • Data: Feb 25, 2022


  • Show Abstract
  • Marine Protected Areas (MPAs) are important mechanisms for the conservation of reef environments, reducing local impacts such as pollution and overfishing, and helping corals survive to global bleaching events. However, many of these areas do not consider climate change in their planning, which may reduce the future protection of corals given the likely change in these species’ distribution. We evaluated the representativeness of zooxantelate shallow-water scleractinian corals in the categories and jurisdictions of the current MPAs network in Brazil. We used gap analysis to investigate changes in future MPA representativeness along the Brazilian province, under the most extreme scenario predicted by the Intergovernmental Panel on Climate Change (IPCC, RCP 8.5). We observed that 21 coral species are included in sustainable use and 19 in strict protection MPAs, and there are no predicted differences in coral assemblage composition between categories or jurisdictions. MPAs are located where there is highest occurrence probability for corals in current and future projections, being mostly represented by the sustainable use categories. As environmental conditions change, subtropical regions will experience increases in coral occurrence probability and these may turn into key areas for coral conservation in the future. Therefore, adopting actions which incorporate climate change in the planning of MPAs may contribute to the survival of these organisms.

6
  • EDILANE MARIA DE LIMA EDUARDO
  • EFFECT OF PRECIPITATION AND PRIMARY PRODUCTIVITY ON PASSERINE BODY MASS IN A RESTINGA AREA IN NORTHEASTERN BRAZIL

  • Advisor : MAURO PICHORIM
  • COMMITTEE MEMBERS :
  • ANGELICA MARIA KAZUE UEJIMA
  • FULVIO AURELIO DE MORAIS FREIRE
  • GUILHERME SANTOS TOLEDO DE LIMA
  • MAURO PICHORIM
  • Data: Feb 25, 2022


  • Show Abstract
  • The way that the body mass of birds varies as a function of climatic and environmental variables has been discussed in several studies in temperate regions, but little is known about how seasonal variations affect the weight of tropical birds. The objective of this work was to describe the weight variations of 29 species of passerines, evaluate whether there is a difference in weight between ages and sexes, and analyze whether precipitation, primary productivity, and diet influence the weight of Passeriformes. Weights were collected between 2010 and 2014 at the Barreira do Inferno Launch Center (CLBI), Parnamirim-RN, northeastern Brazil. The average annual precipitation of the region is 1746 mm, concentrated between March and August, and the vegetation is a mosaic of restinga with herbaceous and shrub formations. The precipitation data are from the CLBI weather station, and the NDVI (Normalized Difference Vegetation Index) was extracted from the SatVeg website and used as a proxy for primary productivity. We adopted the statistical approach of hierarchical model selection based on information theory to test which were the most important predictor variables to explain the variation in weight of the species studied. To do this, we used Generalized Linear Models (GLM), where we considered the random component (response variable weight) being influenced by temporal (precipitation, NDVI, and month) and biological (diet, sex, and age) predictor variables. We used the response variable "weight" standardized by Z-score to be able to compare the various species together We ran t-tests to assess differences in weights between sex and age, and linear regressions to assess whether precipitation and NDVI of the month of capture and months prior to collection influence the weight of individuals. Using standardized weight (Z-score) we saw that juveniles were lighter than adults. We did not detect significant differences in weight between males and females. Rainfall in the month prior to collection and NDVI in the month of collection were the temporal variables that most influenced the weight of adult passerines, the weight of juveniles was not influenced by temporal variables. The guilds were also influenced by the precipitation of the month before and NDVI of the month of collection, being the insectivorous species the only ones in which the weight corresponded to the precipitation of the month of collection.

7
  • ANA BEATRIZ ALVES BENNEMANN
  • FISHING CONFLICTS IN PROTECTED MARINE AREAS: SYSTEMATIC GLOBAL REVIEW AND DELIMITATION OF SARDINE STOCKS (HARENGULA SP.) CONFLICT-TARGET IN BRAZIL

  • Advisor : LIANA DE FIGUEIREDO MENDES
  • COMMITTEE MEMBERS :
  • LIANA DE FIGUEIREDO MENDES
  • LEOPOLDO CAVALERI GERHARDINGER
  • ALEXANDRE SCHIAVETTI
  • ANDERSON VILASBOAS DE VASCONCELLOS
  • Data: Mar 10, 2022


  • Show Abstract
  • Lack of knowledge about taxonomy and population structure of conflict-targeted fish species hinders the correct management of its stocks. The origin of such conflicts in Marine Protected Areas (MPA) are worth investigating in order to propose effective resolutions. With this in mind, this work makes a systematic review of the variables involved in the origin of fishing conflicts in MPAs around the world and investigates the population structure of a species target of conflict in a Brazilian MPA, the scaled-sardine Harengula sp.. In the first chapter, searches were carried out with specific keywords in the Scopus platform, totaling 269 documents analyzed. In the first screening performed by reading the abstracts, 114 articles were selected for full reading, from which 58 were included in the analysis. The main criteria for the selection of articles was the presence of some type of fishing conflict within an MPA. It was found that the main cause of conflict is illegal fishing, followed by a feeling of exclusion from the MPA management and creation process and conflict between fishermen and conservationists. Artisanal fishing, as well as artisanal vessels and artisanal gear, were the most mentioned in the conflicts, indicating that traditional fishermen are the most involved in fishing conflicts. The most conflicting type of management was the governance in sustainable use MPAs. In the second chapter, we used sequences of the mitochondrial DNA control region of 117 individuals from the states of Ceará, Rio Grande do Norte, Paraíba, Pernambuco, Alagoas, Bahia, Espirito Santo, Rio de Janeiro, São Paulo, Santa Catarina, and the islands of Fernando de Noronha (FNO) and Abrolhos (ABR). The lineage delimitation, gene flow and molecular variance analyzes indicated three populations of scaled-sardine along the Brazilian coast: FNO, north, and south clusters. The population in FNO, where the fisheries conflict is stronger, is stock that is diverse and distinct from the one on the northeast coast (including ABR), and the one in the southeast and south of Brazil. These results indicate that temperature and depth act as barriers to gene flow. This work provides a broad view of the origins of fisheries conflicts in marine protected areas around the world and contributes to the understanding of genetic aspects of a target species of a fisheries conflict in a protected area in Brazil.

8
  • MELINA FERREIRA MARTELLO
  • Projected climate-driven shifts in the distribution of Southwestern Atlantic corals support tropicalization

  • Advisor : GUILHERME ORTIGARA LONGO
  • COMMITTEE MEMBERS :
  • CARLA ZILBERBERG
  • GUILHERME ORTIGARA LONGO
  • MARCELO VISENTINI KITAHARA
  • MIRIAM PLAZA PINTO
  • Data: Mar 31, 2022


  • Show Abstract
  • One of the main challenges in framing the future of coral reefs has been to predict species distribution shifts. To investigate which species are most likely to shift their distribution in Southwestern Atlantic (SWA) and how these shifts could alter the composition of coral assemblages in the future, we modeled the occurrence probabilities of 12 zooxanthellate corals that occur in marginal reefs along the Brazilian coast (1°N–27°S). We hypothesized that (i) the distribution of most coral species is likely to expand southwards due to a potential tropicalization of these areas, while tropical areas could become less suitable, and that (ii) corals with a current broader distribution will be more likely to expand their ranges due to greater dispersal potential and tolerance to environmental variability when compared to geographically restricted populations. We used Spatial Distribution Models with a Bayesian approach to predict the species occurrence probabilities in current and future time (2050 and 2100) under an intermediate scenario of increasing greenhouse gas emissions through the 21st century (RCP6.0), projected by the Intergovernmental Panel on Climate Change. We found that the occurrence probabilities of all modeled corals will decline within the tropics (1°N20°S) and increase towards subtropical sites (2027°S) as early as 2050, with major declines predicted to occur between 9°S and 20°S, which coincides with the region comprising the richest reef complex in SWA, the Abrolhos bank. Great declines are expected to occur for Brazilian endemic and range-restricted major reef-builders, Mussismilia braziliensis and Mu. harttii, likely causing loss of structural complexity and its associated biodiversity. Higher occurrence probabilities in subtropical areas support the tropicalization hypothesis in SWA, which should benefit species that are already established in these areas, such as Mu. hispida and Madracis decactis, and potentially enrich coral assemblages through the range expansion of other broadly-distributed species, such as Siderastrea spp., Millepora spp. and Porites spp. These rearrangements could add complexity and functions to these marginal reefs or reverberate in unexpected ways, affecting the provision of goods and services, and drawing attention to the importance of long-term monitoring of reef communities. Predicted losses in tropical and gains in the subtropical regions emphasize the need to support ecological corridors that could aid corals to move towards more suitable areas and thrive facing climate change.

9
  • MARCELLE STEPHANNE BARBOSA DA SILVA
  • Projected impact of future climate change on cultivation of seaweed Gracilaria birdiae on coast of Brazil

  • Advisor : ELIANE MARINHO SORIANO
  • COMMITTEE MEMBERS :
  • ELIANE MARINHO SORIANO
  • EDSON APARECIDO VIEIRA FILHO
  • MARCELO FRANCISCO DE NÓBREGA
  • Data: May 25, 2022


  • Show Abstract
  • Currently, there’s still a knowledge gap on how climate change will affect marine ecosystems and organisms. This knowledge gap is also valid to economically important sectors, such as aquiculture, which cultivates marine organisms. One of the most cultivated organisms in aquiculture is the seaweeds, which the production has been increasing annually, being one of the most promising sectors of aquaculture. The Ecological Niche Modeling (ENM) has currently been applied as a tool to predict the future distribution of species with economic potential regarding environmental and chemical impacts driven by climate change. In this context, this study aimed to evaluate how the projected scenario of future climate change (RCP 8.5) will impact the cultivation of the seaweed Gracilaria birdiae in the Brazilian coast based on the ENM. The modeling was carried out by integrating the MaxEnt algorithm to the RStudio software. The species occurrence data were obtained from the literature. Bioclimatic data were acquired through the Bio-ORACLE database. To validate whether there were significant differences among site suitability at each period, a Friedman test was also performed. The results revealed that the species site suitability will expand in the future and the species distribution was not limited by the temperature. Studies have reported that the genus Gracilaria exhibits a broad range of temperature tolerance, which may explain why the increased superficial seawater temperature will not affect G. birdiae in the RCP 8.5 scenario. In conclusion, the seaweed Gracilaria birdiae shows a great potential for seaweed cultivation in the coast of Brazil, which could lead the country tobecome a major producer of this species.

10
  • MAYCON PEIXOTO XAVIER
  • Detecting changes in marine macroalgae banks through a time series of Landsat satellite images (TM/OLI) for the Brazilian Northeast.

  • Advisor : ELIANE MARINHO SORIANO
  • COMMITTEE MEMBERS :
  • ELIANE MARINHO SORIANO
  • EDSON APARECIDO VIEIRA FILHO
  • MARCELO FRANCISCO DE NÓBREGA
  • Data: May 26, 2022


  • Show Abstract
  • Macroalgae are an essential component of the marine ecosystem as a whole, as they support a large biodiversity while providing for a number of ecosystem services. Notwithstanding their ecological value, macroalgae are also a resource of increasing economic value. The goal of this study was to assess the evolution of macroalgal cover, their distribution as well as their biomass fluctuation along two beach areas located at the coastline of the Rio Grande do Norte State (Rio do Fogo and Baía Formosa beaches), focused on a multitemporal approach. Landsat 5 TM and Landsat 8 OLI satellite digital orbital images were used, covering approx. a 3 decade timespan (1991-2019). From the digital images, it was possible to identify different reef environments included in the total macroalgae coverage area, where the isodata classification separated the environments according to their macroalgae coverage characteristics and according to the degree of inundation in these areas. Concerning the total macroalgal coverage, the Rio do Fogo beach showed an 8% increase in size (from 27.27 ha to 29.34 ha), whereas the Baía Formosa beach showed a 30% decrease in size (from 12.24 ha to 8.55 ha). As to the total biomass, the Rio do Fogo area presented a 63% biomass increase (from 2.436 Kg to 3.967 Kg), vis-à-vis just a slight 19% increase (from 1.206 Kg to 1.438 Kg) at the Baía Formosa beach. Furthermore, it was found from an analysis of vegetation dynamics that the intermediate and lower intertidal zones concentrated the areas with significant reduction at both sites studied. In conclusion, this multitemporal study carried out showed that the use of remote sensing is an effective tool to track fluctuations in macroalgal cover and density, even in situations where field validation is not possible.

11
  • JEAN PAULO SOARES DA SILVA
  • Geographical distribution of amphibians in the Caatinga, Northeast Brazil

  • Advisor : ADRIAN ANTONIO GARDA
  • COMMITTEE MEMBERS :
  • IGOR JOVENTINO ROBERTO
  • ADRIAN ANTONIO GARDA
  • MARCELO FELGUEIRAS NAPOLI
  • Data: May 31, 2022


  • Show Abstract
  • Understanding the spatial organization of species in megadiverse regions, such as the Neotropics, has been a challenge that has fascinated researchers since the first naturalists of the 19th century. We know that the distribution of species is not a random process, and to interpret how they are organized, occurrence maps are essential to understand the distribution patterns of biological diversity. Due to the geographic distributions of many species being little known and full of gaps, a problem known as the Wallacean deficit, which constitutes a huge bottleneck for effective conservation planning. With the objective of contributing to the advancement of knowledge and minimizing the Wallacean deficit on amphibians - a diverse group of vertebrates, threatened and little studied in semi-arid regions - we conducted here a systematic review of primary research and presented the first compilation of distribution and distribution data. Detailed maps for all amphibian species (anurans and caecilians) recorded within the limits of the Caatinga, Northeastern Brazil. All species had their extent of occurrence known in the Caatinga mapped, accompanied by a description of their distribution and conservation status. We provide data on patterns of species richness distribution, sampling gaps, levels of endemism and we provide information on the distribution of each species in the Neotropical region. We created an amphibian database from the direct analysis of 29.831 occurrence records, with respective vouchers, within the limits established for Caatinga. We recorded 121 amphibian species in the Caatinga, belonging to 18 families. In addition to species that occur in other natural regions, 19 amphibian species are endemic (16,53% of the total species). The richest family was Hylidae with 46 species (38,02% of the total species), followed by  eptodactylidae with 31 (25,62% of the total species). Our results support new ecological studies and herpetofauna inventories, and also contribute to decision making regarding priority areas for amphibian conservation in the Caatinga of Northeast Brazil. 

12
  • NATHÁLIA NAPOLE DE OLIVEIRA
  • EFFECTS OF LARGE HYDROELECTRIC PLANTS ON ARTISANAL FISHERIES IN FRESH WATER SYSTEMS

  • Advisor : PRISCILA FABIANA MACEDO LOPES
  • COMMITTEE MEMBERS :
  • EDER MILENO DILVA DE PAULA
  • MONALISA RODRIGUES OLIVEIRA DA SILVA
  • PRISCILA FABIANA MACEDO LOPES
  • Data: May 31, 2022


  • Show Abstract
  • Large hydroelectric power plants (HPP) impact subsistence fishing. Despite that, few studies have delved into these impacts. In the present research, we aim to evaluate the impacts of UHE Belo Monte on fish co-occurrence networks. Specifically, we seek to analyze these networks considering the areas of influence of the plant (upstream, reservoir, stretch of reduced flow and downstream) between two periods (2012-2015 and 2016-2020), identify the key fish groups for each region in the period operation of the enterprise (2016-2020) and discuss how changes in subsistence fishing can affect food security for populations dependent on these resources. Our hypothesis is that there is replacement of species that co-occur in subsistence fisheries between different areas of influence of the HPP. Since changes in local diversity influence the decline in fishery resource diversity, we also hypothesize that species groups will be distinct between the previous period (2012-2015) and the period of operation of the HPP (2016-2020). The database used in this study comes from the monitoring of subsistence fisheries carried out between the municipalities of Altamira and Porto de Moz, Pará, Brazil. The analysis of the cooccurrence models was based on graph theory. The models resulting from the 2016-2020 period were used to design new networks with removal of the core species groups. As a result, we saw that the groups of species vary between the areas of influence and downstream is the one with the highest number. Among the periods, the one that presented more groups of species was the one before the operation of the HPP.
    The projections showed significant alterations in the conformation of the co-occurrence networks, mainly for the reduced flow section. We conclude that UHE Belo Monte has an impact on subsistence fisheries in the region, altering the composition of fishery resources in space and time.

13
  • LUAN SOUZA DA FONSECA
  • PERFORMANCE OF NATIVE SPECIES AND THE COMPOSITION OF PLANTED COMMUNITIES ALONG 5 YEARS OF BRAZILIAN DRYLAND RESTORATION

  • Advisor : GISLENE MARIA DA SILVA GANADE
  • COMMITTEE MEMBERS :
  • EDSON APARECIDO VIEIRA FILHO
  • GISLENE MARIA DA SILVA GANADE
  • MILENA CORDEIRO DE AMORIM LOPES
  • Data: Jun 23, 2022


  • Show Abstract
  • In the decade of ecosystem restoration, it becomes necessary to reverse the advance of degradation of natural environments, aiming at sustainable development and ensuring human well-being. To achieve this goal, we must think about the restoration of dryland environments that represent 47% of the land surface, such as the Caatinga, a Brazilian semi-arid ecosystem that covers an area of approximately 912,000km². To scale up restoration projects in this biome, we must understand which species and community compositions can ensure greater success in restoration projects. The aim of this work was to identify species and compositions that show good potential for restoration in the Caatinga. We analysed a five-year period of the first cohort of the BrazilDry experiment located in Açú National Forest (Rio Grande do Norte, Brazil). Using analyses of variance with Tukey&#39;s a posteriori test, we tested which species and communities, exhibit: (1) stability in first cohort mortality (species only) and percent survival, (2) mean height, (3) mean annual growth, (4) photosynthesizing biomass production, and (5) diameter above ground (DAS). For the species, all the investigated variables were significant with values of P=&gt;0.001. We found that only one species showed average survival below the stipulated (16%) after five years of planting and more than half show some stability in the cohort. Most species presented height and DAS within the assumed ranges for the work (1 to 2m and 10 to 20mm, respectively), besides presenting, in general, an annual growth between 0m to 0.5m. M. tenuiflora was the highlight in the production of photosynthesizing biomass and DAS, with values exceeding 200g and 30mm, respectively. Regarding plant compositions, only survival and photosynthesizing biomass differed with P=&gt;0.001. Only one composition is not above the 16% survival range. The monoculture of M. tenuiflora differs from all other  compositions in the production of photosynthesizing biomass. The stability in the survival curve of the species presents some stability between 2-4 years due to the technique of root extension. The height and growth show satisfactory results, even with the limitation of their development caused by the dry period, competition with exotic herbaceous species and the capacity for regrowth. The photosynthesizing biomass and DAS are driven by
    species diversity, however, in its establishment and growth phase competitive interactions may prevail. This work brings a selection of native species and communities that perform well over 5 years restoration in Caatinga, presenting characteristics that define their potential in the recovery of degraded areas. 

14
  • JÉSSICA VARGAS DE OLIVEIRA
  • Climate change in the distribution of the Buff-Headed Capuchin (Sapajus xanthosternos)

  • Advisor : MIRIAM PLAZA PINTO
  • COMMITTEE MEMBERS :
  • EDSON APARECIDO VIEIRA FILHO
  • MILENA CORDEIRO DE AMORIM LOPES
  • MIRIAM PLAZA PINTO
  • RAONE BELTRÃO MENDES
  • Data: Jul 14, 2022


  • Show Abstract
  • Accelerated changes in climate influence biodiversity and species distribution. To increase the species' survival prospects, it is necessary to guarantee the maintenance of habitats with an adequate climate. In this work we evaluated the effects of predicted climate change along the geographic distribution of the yellow-breasted capuchin monkey (Sapajus xanthosternos), a primate classified as critically endangered. We compared the characterization of the present and future climatic pattern in the species distribution; and we evaluated the difference between the climate suitability of the present time, and for the expected future in the face of climate change. Our results show that climate change will occur heterogeneously along its distribution. In 75% of its area of occurrence there will be a temperature increase with values greater than 4oC of temperature. The regions with the highest levels of rainfall in the present time are the regions where the greatest decrease in rainfall of up to 400 mm will occur in the future. We also found an increase in temperature and precipitation variation for the entire range of occurrence of the species. We found an abrupt loss of climate suitability in the distribution of the species, if the predictions for the most pessimistic scenario of climate change occur. Our results emphasize the importance of maintaining and restoring  habitats with suitable climatic niches in the region east of the distribution where there will be the highest values of climatic suitability that will be fundamental for the preservation and conservation of the species.

15
  • CASSIA FERREIRA DE OLIVEIRA
  • SPATIAL DISTRIBUTION OF THE MYRTACEAE EVOLUTIONARY DIVERSITY IN THE ATLANTIC FOREST

  • Advisor : VANESSA GRAZIELE STAGGEMEIER
  • COMMITTEE MEMBERS :
  • VANESSA GRAZIELE STAGGEMEIER
  • PRISCILA LEMES DE AZEVEDO SILVA
  • THAIS NOGALES DA COSTA VASCONCELOS
  • Data: Jul 26, 2022


  • Show Abstract
  • The Atlantic Forest is a global biodiversity hotspot, and it is essential to comprehend the ecological and evolutionary processes responsible for shaping highly diverse environments. This comprehension allows a theoretical advance on the factors raising diversity, but also a practical advancement increasing the effectiveness of the spatial prioritization of areas to be protected, contributing to the conservation of hotspots. In the Atlantic Forest, Myrtaceae stands out as the most diverse woody plant family (691 species) and is an excellent model for studies because its richness patterns are representative of other taxa. Thus, this work had two objectives: (1) to map the evolutionary diversity metrics of Myrtaceae in this domain in order to understand the evolution of the Atlantic Forest flora, and (2) to assess whether the current network of conservation units in the Atlantic Forest is representative of the evolutionary diversity of the domain. We used information from articles that conducted studies in floristics represented on two databases, Caaporã and NTT, which were reviewed before analyses to correct potential species occurrence and/or nomenclatural errors. The records used summed 492 Myrtaceae species occurring in 1282 sites. The sampling of geographic space showed good coverage and robust representation of the environmental space of the domain. We found that evolutionary hotspots are concentrated in the southern portion of the Atlantic Forest, in southern and southeastern Brazil. On the Brazilian coastal regions, from the south to the northeast, are the areas with higher concentration of derivate lineages and species that are more closely related to each other, while in the interior of the southern region, the deepest lineages are concentrated. The existence of temporally stable climatic refugia to the south of the domain, as well as the history of colonization and expansion of this family in the South American continent, which begins in the south and expands to the northward, may explain the concentration of older lineages in the south of the domain. In Santa Teresa/ES and in the coastal forests of southern Bahia (Ilhéus/BA) we recorded the greatest diversity of phylogenetic endemism, sites that harbor unique lineages, restricted to these regions. The patterns of phylogenetic diversity of Myrtaceae described here corroborated patterns already described for other terrestrial taxa, such as birds and arthropods, which reinforces the use of Myrtaceae as a model group for macroecological and macroevolutionary analyses in the Atlantic Forest. The current network of protected areas in the Atlantic Forest covers part of the evolutionary history exhibited in Myrtaceae for the metrics of phylogenetic endemism and mean root distance. However, this network did no protect all variation on phylogenetic variability and diversity. This result urges future studies focusing on the indication of new areas to preserve all evolutionary components. Conserving evolutionary potential is a way to increase the chances of taxa responses to the scenarios of environmental changes predicted for the future. The results produced here should be included in spatial prioritization analyses. 

16
  • JONATHAS GABRIEL SUDARIO BARROS
  • HABITAT USE AND OCCUPANCY OF THE WILSON’S PLOVER (CHARADRIUS WILSONIA): A CONTRIBUTION TO THE NATIONAL ACTION PLAN FOR THE CONSERVATION OF MIGRATORY SHOREBIRDS.

  • Advisor : MAURO PICHORIM
  • COMMITTEE MEMBERS :
  • GUILHERME SANTOS TOLEDO DE LIMA
  • JOÃO PAULO TAVARES DAMASCENO
  • MAURO PICHORIM
  • Data: Aug 2, 2022


  • Show Abstract
  • Coastal areas are important habitats for shorebirds, among them, the Wilson’s Plover (Charadrius wilsonia), a medium-sized bird with a distribution from North America to northeastern Brazil along the Atlantic coast and from Mexico to Peru along the Pacific. Despite its distribution, little is known about the ecology of this species in the southern hemisphere. Our objective was to estimate demographic and occupancy data of C. wilsonia, in order to contribute to the achievement of objective 4.1 of the National Plan for the Conservation of Migratory Shorebirds. For this purpose, we used the State Sustainable Development Reserve Ponta do Tubarão/RN for data collection, where we conducted three transects (named MDG, MPA and P) with 12 observation points spaced every 300 m. The collections occurred in two seasons, rainy and dry, comprising the months of February to May, and August to November, respectively. With this, we assembled presence and absence histories for static occupancy modeling (single-season) in the MARK program. A total of 128 models were generated from the global model. The detection probabilities were set to vary with the tide. As main results of theoccupancy models we have that the transects were relevant, along with the presence of dunes, underbrush and sandy beach. The MDG transect obtained the highest occupancy rate (Ѱ = 0.88), followed by MPA (Ѱ = 0.58) and P (Ѱ = 0.12). The presence of dunes negatively affected the occupancy of C. wilsonia, while underbrush and sandy beach had a positive but still uncertain interaction. The results indicate that the occupation pattern of C. wilsonia seems to be influenced by food availability and protection, where in regions with dunes they are more exposed to predators and with a greater scarcity of food. Our findings will directly contribute to the population and habitat research goals outlined in the National Action Plan for the Conservation of Migratory Shorebirds, and complement the limited data on occupancy and habitat use related to the ecology of the Wilson’s Plover outside of North America.

17
  • FERNANDA VITORIA SILVA DO NASCIMENTO
  • INFLUENCE OF SALINITY ON THE PERFORMANCE OF NATIVE SPECIES SEEDLINGS IN A CAATINGA RESTORATION PROGRAM

  • Advisor : GISLENE MARIA DA SILVA GANADE
  • COMMITTEE MEMBERS :
  • GISLENE MARIA DA SILVA GANADE
  • EDUARDO MARTINS VENTICINQUE
  • MARINA VERGARA FAGUNDES
  • Data: Aug 30, 2022


  • Show Abstract
  • The Caatinga is characterised by a semi-arid climate, high temperatures, high evaporation rates and geological conditions that favour greater soil fertility and rapid plant growth in the rainy season, but also a greater accumulation of salts in the soil, which can impair plant development. To increase the efficiency of restoration in degraded areas, studies of plant responses to both soil fertility and salinity are necessary. This study was conducted in a restored area of Caatinga and aims to: 1) Characterize the levels of salinity and fertility of the soil in this restored area; 2) Test how salinity and fertility contribute to the success of restored communities, in terms of  survival; 3) Test how different compositions of restored communities could influence soil parameters after 5 years of restoration. The study was conducted at FLONA de Açu-RN, in an experiment established 2016 in a degraded Caatinga area. The site was divided into 155 plots, where native seedlings were planted with five different levels of richness (1, 2, 4, 8 and 16). The work was carried out in all monocultures and in the plots where all tree species were planted together (16 species). In these plots soil samples were collected and analysed for fertility and salinity parameters that were calculated according to the Embrapa methods manual. To test whether soil salinity and fertility characteristics (explanatory variables X) influence the survival of tree communities (response variable Y), we used Mixed Models in R software, observing how the continuous parameters of salinity, fertility and the two levels of vegetation diversity (1 and 16 species) affect the survival of planted tree species. To test whether the species composition of monoculture and polyculture (explanatory variable X) has any effect on soil parameters (response variables Y) a MANOVA was performed using the soil parameters that were not previously correlated. The results showed that the soils are not saline and that several plots show good fertility. For salinity-related parameters, increasing Electrical Conductivity reduced species  survival in mono and polycultures, whereas high potassium (K) availability generated higher survival rates in the plots. For fertility parameters, high availability of potassium (K) was also observed in higher survival plots, while high availability of Organic Matter generated lower survivals. No significant difference was found in soil arameters for both salinity and fertility in relation to monocultures and polycultures in these first 5 years of restoration demonstrating that tree species, in this space of time, are not yet able to alter the quality of the soil. The work also demonstrates that a greater amount of potassium in the soil can lead to an increase in seedling survival in Caatinga restoration programmes.

Thesis
1
  • RAUL MARIO DA SILVA PEIXOTO NETO
  • Litter decomposition in a restoration area in the Caatinga: effects of facilitation, neighboring vegetation and seasonality

  • Advisor : GISLENE MARIA DA SILVA GANADE
  • COMMITTEE MEMBERS :
  • RITA SOUSA SILVA
  • ADRIANO CALIMAN FERREIRA DA SILVA
  • CARLOS ROBERTO SORENSEN DUTRA DA FONSECA
  • FELIPE PEREIRA MARINHO
  • GISLENE MARIA DA SILVA GANADE
  • Data: Apr 28, 2022


  • Show Abstract
  • he decomposition of litter is the main nutrient pathway between vegetation and soil. In forest ecosystems the vegetation community determines both the volume and quality of the litter, besides modifying abiotic conditions that directly affect the activity of detritivores organisms below the canopy. In semi-arid environments, such as the Caatinga in Northeastern Brazil, the environmental stress mitigation effect promoted by vegetation helps plant recruits and the detritivore community to face limiting conditions, making facilitation relationships an important modulator of the plant community in this biome. In the present study, litter production and decomposition were measured during the dry and rainy seasons in Caatinga in order to assess: (I) How leaves of nurse species influence litter decomposition and nutrient cycling; (II) How the diversity of neighboring plants influence litter decomposition; and (III) The effect of the herbaceous community on leaf decomposition of tree species during restoration in the Caatinga. The results obtained show that nurse plants have greater potential for tree-soil nitrogen transfer through leaf fall and that the functional traits of their leaves promote synergistic effects on litter decomposition. Also, that the abundance of neighboring trees influences the decomposition of relatively less labile detritus. Also, that detritus from the herbaceous stratum positively affects the decomposition of tree leaves. Furthermore, the results show that the quality of the litter and rainfall are determinants for the decomposition process in the Caatinga. Thus, the study assists in understanding the mechanism of nutrient supply in facilitating interactions between plants in the Caatinga and the importance of maintaining vegetation to promote efficient nutrient cycling, as well as highlighting the fundamental role of rainfall for the functioning of ecosystems in semi-arid environments.

2
  • RANDSON MODESTO COÊLHO DA PAIXÃO
  • OCCUPANCY OF ENDEMIC AND THREATENED PASSERIFORMES IN A HIGHLY FRAGMENTED ENDEMIC CENTER

  • Advisor : MAURO PICHORIM
  • COMMITTEE MEMBERS :
  • GUILHERME ORTIGARA LONGO
  • GUILHERME SANTOS TOLEDO DE LIMA
  • JOÃO PAULO TAVARES DAMASCENO
  • JULIANA DEO DIAS
  • MARCELO DA SILVA
  • MAURO PICHORIM
  • Data: Apr 29, 2022


  • Show Abstract
  • Our objective was to estimate the occupancy of endemic and threatened passerines in the Atlantic Forest north of the São Francisco River, Brazil, and to analyze the factors that enhance their distribution. The occupancy of bird taxa was modeled and used to predict the direction of response of eight covariates based on prior knowledge of bird ecology. A priori, the covariates measured are expected to represent the key habitat characteristics for the species (i.e. temperature, precipitation, forest area, elevation) or anthropogenic effects (here, distance from roads and the urban perimeter, for example) to be harmful the birds in focus, based on the hypothesis that anthropogenic factors would have a negative effect on occupancy in CEE, while habitat covariates would have positive effects on the occupation of rare birds. We used data available in the literature, online databases, ornithological collections and from researchers in the region to estimate the parameters using single-season occupancy models. The occupancy of the grid was best described by two variables: altitude and forest area. The detectability was affected by the trend of linear effort over time, which indicates that the increase in the sample effort was important for most of the studied taxa. Our study provides robust information on the influence of covariates studied on endemic and threatened passerines and is the first study to provide data on large-scale anthropogenic effects in occupancy for most endangered and endemic species in this endemism center. The data indicated that the occupancy and detectability of the species was influenced by single variables of greater weight, but that possibly act in conjunction with multiple factors. The generated maps provide information that can be useful in management and action plans for the conservation of the areas where this species occurs, which favors the allocation of resources. Understanding the covariates studied can also potentially reduce the risk of worsening bird losses through policy measures for habitat management in the region.

3
  • ALEX BARBOSA DE MORAES
  • Invasibility potential of Penaeus vannamei Boone, 1931 (Crustacea, Decapoda, Penaeidae) on the Atlantic coast of the Americas

  • Advisor : FULVIO AURELIO DE MORAIS FREIRE
  • COMMITTEE MEMBERS :
  • FULVIO AURELIO DE MORAIS FREIRE
  • LUISA MARIA DIELE VIEGAS COSTA SILVA
  • Adilson Fransozo
  • FLAVIA LUCENA FRÉDOU
  • ROGÉRIO CAETANO DA COSTA
  • Data: Jun 13, 2022


  • Show Abstract
  • The Penaeidae shrimp represents one of the most economically profitable fishing resources in the world. Therefore, in several regions of the world there is a large investment in shrimp farms for the production of cultivated shrimp. Currently, the P. vannamei species, originally from the American Pacific Ocean, appears as one
    of the most productive species in the world industry. However, the intense use of this species for cultivation has led to increasingly frequent records of its presence in natural marine ecosystems, far from their native geographic distribution. Recent studies show that the scarcity of information and research does not allow to indicate the establishment of natural populations of this exotic species or determine its invasive potential. Having that in mind, this thesis investigated the climate compatibility of the Americas’ West Atlantic Coast, in the present and future scenarios, considering different climate change predictions for the colonization and natural dispersion of this exotic species of shrimp. The invasive potential of exotic shrimp was also assessed through a comparative approach of climatic niche with related and native species of the Atlantic. Modern consensual multi-modal niche techniques applied to geographic space were used in conjunction with an Environmental PCA approach to assess the ecological niche in the environmental space. The results indicate that the receiving range of the exotic species presents a wide area with climate compatibility for survival and expansion of possible self-sustaining populations (establishment) of P. vannamei in a natural environment, encompassing areas around the main shrimp farming centers in the Americas. Analyses of the occurrences already recorded in the exotic range suggest changes in the realized niche of the specimens. Future Habitat Suitability analysis indicates stability in potential areas of invasion. Additionally, niche overlap analyses reveal potential overlap of the environmental space used by P. vannamei in relation to other marine shrimps from the Atlantic coast. Therefore, it is concluded that there is an invasive potential of P. vannamei throughout the West Coast of the Americas.

4
  • HENRIQUE DOUGLAS DOS SANTOS BORBUREMA
  • EFFECTS OF GLOBAL CHANGE ON THE PHYSIOLOGY OF Bostrychia spp. (RHODOPHYTA) FROM GENETICALLY DIVERGENT TROPICAL AND SUBTROPICAL POPULATIONS

  • Advisor : ELIANE MARINHO SORIANO
  • COMMITTEE MEMBERS :
  • ELIANE MARINHO SORIANO
  • JULIANA DEO DIAS
  • EDSON APARECIDO VIEIRA FILHO
  • ESTELA MARIA PLASTINO
  • VINICIUS PERUZZI DE OLIVEIRA
  • Data: Jul 12, 2022


  • Show Abstract
  • Increased greenhouse gas concentrations in the Earth’s atmosphere have resulted in an atmospheric and oceanic warming. Global warming has caused climate change and sea level rise worldwide. Estuarine salinization is expected due to the sea level rise, longer droughts, and estuary warming. In addition to these global changes, a decrease in oceanic pH has been recorded because of increased dissolved carbon dioxide (CO 2 ) in seawater, an environmental disturbance termed ocean acidification. Fluorinated gases emitted into the atmosphere, in addition to being greenhouse gases, lead to a stratospheric ozone depletion, resulting in a higher harmful solar radiation on the Earth. Primary producers in coastal ecosystems such as mangrove swamps can be negatively affected by these global changes. Thus, in this thesis, we investigated the physiology of the mangrove macroalgae Bostrychia montagnei and Bostrychia calliptera from tropical and subtropical populations after being subjected to global change experimental conditions. The genetic divergence between tropical and subtropical macroalgal populations was also investigated using mitochondrial (COI-5P) and plastidial (rbcL- 3P) DNA markers. The results from our investigation are shown in five scientifi articles, whose main results are briefly described hereafter. In the first article (doi.org/10.1016/j.jembe.2022.151740), we reported that tropical macroalgal populations are genetically divergent from subtropical macroalgal populations, based on the COI-5P marker. We also demonstrated that macroalgae from both climatic niches are tolerant of decreased pH (7.6 and 7.2) by CO 2 enrichment of the seawater (ocean acidification), increasing their growth under decreased pH treatments due to increased CO 2 availability for photosynthesis. Tropical B. montagnei increased its polysaccharide and allophycocyanin content at pH 7.2, and subtropical B. montagnei increased its low molecular weight carbohydrate content at pH 7.2 as well. In the second article (doi.org/10.1016/j.marenvres.2022.105662), we reported that tropical and subtropical B. montagnei and B. calliptera decreased their growth and photosynthetic performance under simultaneous increase in temperature and salinity. We evidenced that macroalgae synthesized proteins, carbohydrates and antioxidants to tolerate detrimental temperatures and salinities, as well as they adjusted their pigment contents (phycobiliproteins, carotenoids, and chlorophyll a) for efficient light-harvesting under thermal and saline stress. In the third article, we observed that tropical B. calliptera and B. montagnei decreased their photosynthetic performance under rising salinity  (salinization in tropical estuaries influenced by semi-arid climate). Bostrychia montagnei showed osmotic acclimation by synthesizing and accumulating organic osmolytes dulcitol and sorbitol under rising  alinity, whereas B. calliptera mainly synthesized and accumulated dulcitol. Sorbitol was only synthesized by B. calliptera at salinities of 37.1, 47.1, and 57.3 S A , as a trace compound. Between species, B. montagnei showed a greater photophysiological tolerance to the salt stress by synthesizing and accumulating both dulcitol and sorbitol, since sorbitol is a physicochemically better osmolyte than dulcitol. In the fourth article, we registered that under increase in photon flux density (increased solar radiation on the Earth due to stratospheric ozone depletion), tropical B. calliptera and B. montagnei exhibited a lower photosynthetic performance. We also recorded a photodamage on the pigment content of B. montagnei under light stress, whereas in B. calliptera a photodamage was only observed on its chlorophyll a content. In both species a photodamage was also registered on their mycosporine–like amino acid (photoprotective compounds) contents under increasing light stress. More pronounced photodamage was observed on B. montagnei. This lower tolerance of B. montagnei to the light stress may explain its preferential occurrence at more shaded microhabitats, as documented in the scientific literature. In the fifth article, we evidenced that tropical and subtropical B. montagnei and B. calliptera increased their dulcitol and sorbitol concentrations under decreased pH by CO 2 enrichment of the seawater. Thus, these polyols also have an energetic function. The carbon content in the macroalgae also increased under ocean acidification. Tropical and subtropical B. montagnei and B. calliptera increased their dulcitol and sorbitol contents under rising temperature and salinity. This demonstrates that these polyols also have a thermal protection function in Bostrychia species. In conclusion, our data support that tropical and subtropical  opulations of B. montagnei and B. calliptera are genetically divergent and benefit from increased CO 2 in seawater, since they increased their productivity and were tolerant of decreased pH. Thereby, these macroalgae can be relevant for CO 2 sequestration in mangrove ecosystems. However, the ocean warming and increased salinity in estuaries will be detrimental to the physiological performance of macroalgae from both climatic niches, even as they adjust their metabolism to synthesize compounds related to thermal and saline tolerance. Our data suggest that tropical macroalgal populations are more vulnerable to warming than subtropical populations, since tropical populations already live closer to their upper thermal tolerance limits. Our data also demonstrate that both species are euryhaline and can be characterized as typical “shade plants”. Thus, increased solar radiation on estuarine ecosystems due to global change will be harmful to both Bostrychia species. In our investigation, we documented for the first time the effects of ocean acidification on Bostrychia species, the first COI-5P sequences generated for both species, physiological strategies of Bostrychia spp. for thermal acclimation, a lethal temperature condition for Bostrychia species (34 ºC for the tropical specimens), a new organic osmolyte distribution pattern in Bostrychia species (only dulcitol in B. calliptera), and the deleterious effects of increased light stress on Bostrychia spp.

5
  • PRISCILA ALBUQUERQUE DE MOURA
  • Spatial memory and learning in Heliconius butterflies

  • Advisor : MARCIO ZIKAN CARDOSO
  • COMMITTEE MEMBERS :
  • ERIKA CRISTINA PINHEIRO DE CASTRO
  • KEMAL ALI GER
  • LAWRENCE E GILBERT
  • MARCIO ZIKAN CARDOSO
  • STEPHEN HUGH MONTGOMERY
  • Data: Jul 20, 2022


  • Show Abstract
  • Animals that encounter a certain degree of variation throughout their lives should benefit from the ability to learn and memorize where and when to find food. Although it is clear that learning and memory are important for navigation, habitat exploration, and memorization of landmarks in many species of insects, these behaviours and their neural basis are largely well studied in social insects. Neotropical butterflies of the genus Heliconius (Heliconiinae, Nymphalidae) are emerging system for the study of learning, memory, and adaptive brain elaboration. Many of their unique ecological and behavioural characteristics (pollen feeding, limited home range, trap-lining behaviour, nocturnal gregarious roosting sites) suggest that spatial memory in particular may be essential for their survival and reproduction, particularly linked to the recognition of long-distance visual stimuli, as landmark-learning is thought to play a central role in navigation during foraging. In this context, this doctoral research aims to answer the central question “Is there evidence spatial memory in Heliconius butterflies?” Therefore, in chapter one, we use a mark-release-recapture experiment to test whether individuals of two Heliconius species exhibit true site fidelity. We further test this fidelity by measuring flight orientation during a translocation experiment, and by recapturing translocated butterflies to identify whether individuals return to their site of origin. We found that 214 non-translocated butterflies display extreme stability in site choice, and 144 translocated butterflies consistently return to their site of origin, rapidly orientating towards their home site upon release. This suggests site fidelity in Heliconius is not solely explained by low dispersal, but is a response to the distribution and stability in ecological resources. In chapter two, we found experimental evidence for spatial learning in a foraging context at different  spatial scales (9m 2 e 100m 2 ). In chapter three, we used a set of three experiments to test for evidence of spatial learning associated with the presence of landmarks. We tested whether they learned to find food in an experiment where (1) the location of both the reward and the landmark is fixed; (2) the location of both changes throughout the experiment; and (3) the location of both is fixed, but in an experimental cage with covered walls to avoid interference from external visual cues. We found that butterflies learn the location of the reward when it is predictable (fixed), regardless of the presence of landmarks, and that learning appears to be aided by the use of external visual cues. Finally, in chapter four, we provided new evidence contrary to the long-standing hypotheses that Heliconius butterflies may use social information to learn the location of new resources. We found that experimental butterflies from two groups with demonstrator butterflies with different colour preferences presented a similar learning rate, demonstrating that learning of a foraging task is not facilitated in a social context. This supports the contention that foraging decisions in Heliconius butterflies are influenced by innate biases and individual experience, rather than social information from conspecifics.

6
  • KARLA JULIETE DE PAIVA SILVA DE SOUZA
  • Spatial variation in Latin American tree biodiversity: patterns and determinants

  • Advisor : ALEXANDRE FADIGAS DE SOUZA
  • COMMITTEE MEMBERS :
  • VINÍCIUS DE LIMA DANTAS
  • ALEXANDRE FADIGAS DE SOUZA
  • MARCELO FREIRE MORO
  • MIRIAM PLAZA PINTO
  • VANESSA LEITE REZENDE
  • Data: Jul 27, 2022


  • Show Abstract
  • Bioregionalization is the effort to identify and map geographical boundaries for distinct biota at different spatial scales. Clear delineation of biogeographic units based on community data can provide a framework for testing hypotheses and for directing biodiversity conservation efforts. The aim of this Thesis is to identify and map tree biogeographic units in Latin America at different spatial scales, investigate the floristic relationships between the identified units and the main factors responsible for the formation of floristic units in geographic space. The Thesis is structured in three articles. We used a community-level modelling approach, and hierarchical and non-hierarchical classification techniques to map the biogeographic units at different spatial scales. In Article I, we compiled woody species occurrence data from 301 assemblages distributed over the geographical extent of the Amazon rainforest. Occurrence data were used to model the b-diversity along the entire extent of the Amazon and thus to map floristic units (subregions). We used multinomial logistic regression model and statistical deviance partitioning to investigate the influence of environmental, historical and human factors on the distribution of Amazonian subregions. We identified 13 woody subregions in the entire Amazon Forest. The hierarchical subregion classification showed a broad Andean-Cratonic east–west division. Variation in subregions was explained jointly by human factors and spatial structure followed by environmental factors and spatial structure combined. In article II, we propose two bioregionalization schemes for tree species of the Cerrado-Pantanal complex, based on occurrence and abundance data. We also evaluated the contribution of three sets of determinants of the occurrence- and abundance-based subregions. For modelling, we compiled data on tree species composition from 894 local assemblages based on species occurrences, and from 658 local assemblages based on species abundances. We identified 18 occurrence- and four abundance-based subregions in the Cerrado-Pantanal complex. Variation in subregions were explained mainly by environmental factors and spatial structure in both occurrence and abundance datasets. The occurrence and abundance-based subregions are complementary approaches to disentangle the macroecological patterns and to conservation planning in the Cerrado-Pantanal complex. In Article III, we present regionalizations of the tree flora of Latin America using two dimensions of b-diversity, taxonomic and phylogenetic. We assessed taxonomic and phylogenetic floristic relationships between groups at different spatial scales. We used species occurrence data from 7306 tree assemblages to model taxonomic and phylogenetic b-diversity across Latin America. We identified 128 taxonomic tree subregions and 101 phylogenetic subregions. The tree subregions were grouped into 54 mesoregions, 16 macroregions and 9 supraregions. Phylogenetic subregions were grouped into 46 mesoregions and 15 macroregions. Our proposed bioregionalization in Latin America revealed a detailing of tree biodiversity patterns not usually presented in continental-scale studies, revealing ecotone areas between known biome boundaries, as well as the evolutionary and geographic history between regions.

7
  • JEANNE RAQUEL DE ANDRADE FRANCO
  • Interactions of Woody and Herbaceous Vegetation: Implications for Ecological Restoration in the Semiarid

  • Advisor : GISLENE MARIA DA SILVA GANADE
  • COMMITTEE MEMBERS :
  • RENATO GARCIA RODRIGUES
  • FERNANDA ANTUNES CARVALHO
  • GISLENE MARIA DA SILVA GANADE
  • JOSÉ ALVES DE SIQUEIRA FILHO
  • VANESSA GRAZIELE STAGGEMEIER
  • Data: Jul 28, 2022


  • Show Abstract
  • The Caatinga biome is one of the largest seasonally dry tropical forests in the world and home to a high diversity of species. Despite this, this biome is susceptible to anthropogenic disturbances and invasion of exotic species, which leads to the loss of native species. Non-tree life forms also contribute to the richness and functioning of the ecosystem, but little is known about the interactions between herbaceous and tree communities. The objective of the first chapter was to evaluate the influence of herbaceous vegetation on the colonization of two native species Anadenanthera colubrina and Astronium urundeuva and an axotic species Leucaena leucocephala in a degraded area. We found that the herbaceous vegetation impairs the growth of the native tree species and has a neutral effect on germination, establishment, and growth of the exotic species. These results raise important questions about restoration methods with native species and management of exotic species in the Caatinga. The objective of the second chapter was to evaluate how tree species richness (control, 1, 2, 4, 8, and 16species) and their compositions affect the richness, percent cover, height, and species composition of the herbaceous vegetation. Tree richness did not affect the richness and percent cover of the herbaceous shrub vegetation, however, there were differences in percent cover by species among the levels of tree richness and limited effect of richness on species composition and vegetation height. Composition interfered with height, percent cover, richness, and composition of herbaceous and shrub vegetation, indicatingthat species composition during the early growth stage of arboreal trees is important for planning restoration methods. The functional attributes of the tree species, such as leaf biomass, leaf area, number of leaves, height, diameter, and number of leaves showed overall negative effects, indicating competition between herbaceous and tree species. The objective of the third chapter was to evaluate how the percent cover, height, and presence of vines of herbaceous and shrub vegetation, including interactions with tree species richness and composition, affect the growth attributes height and diameter at ground height and survival of native tree species during ecological restoration. Negative and positive effects occurred for interactions between herbaceous and tree vegetation depending on tree species composition. The greater height, diameter at ground height (DAS) and survival of tree species were associated with the presence of climbers in the herbaceous- shrub layer. It was found that tree richness and composition alone did not explain tree growth and survival variables. The best selected models include richness and composition acting simultaneously with the herbaceous shrub vegetation variables. According to these results, it is important to consider herbaceous species diversity and tree compositions for effective ecological restoration in the semi-arid region.

8
  • MARCELO CÂMARA RODRIGUES
  • Reproduct biology, habitat use and social structure in Cyanocorax cyanopogon (Whaite-naped Jay)

  • Advisor : MAURO PICHORIM
  • COMMITTEE MEMBERS :
  • PEDRO DINIZ ALVES
  • ANGELICA MARIA KAZUE UEJIMA
  • DANIEL MARQUES DE ALMEIDA PESSOA
  • MAURO PICHORIM
  • VANESSA GRAZIELE STAGGEMEIER
  • Data: Jul 29, 2022


  • Show Abstract
  • Although costly, group living is widely distributed in nature. Among birds, crows and ravens (Corvidae) stand out for their cognitive ability and for forming social groups that provide better performance in caring for offspring. Cyanocorax cyanopogon (White-naped Jay) are endemic to Brazil and occur mainly in Caatinga and Cerrado, two
    biomes with strong seasonal component, alternating between periods of low and high productivity. In order to understand the strategies used by these birds to live in these biomes: 1) we will verify if they adjust their reproduction to the availability of resources in the environment; 2) we will analyze if the environmental characteristics and the availability of resources interfere with their occurrence in an area of Caatinga; and 3) we will describe the social structure of the groups of individuals that use the area of the FLONA-Açu. In our records of nests we found that the development of the nestlings lasts about 7 months, from the construction of the nest until they acquire adult plumage. Putting our reproductive records together with those available on Wikiaves and comparing them with the WorldClim precipitation data, we found that most of the records anticipate the month with the highest rainfall volume. We also found that this trend is stronger in the Cerrado than in the Caatinga. We compared 128 models generated from our global model with 8 environmental variables. Of the total, 5 models were the most representative. The most relevant parameters for occupancy were: season, distance from headquarters and NDVI (Normalized Difference Vegetation Index). In this model the occupancy estimate for the rainy period was almost half of what was observed in the dry period. Occupancy also varied positively as a function of NDVI and negatively as a function of distance from headquarters, both with greater effect in the rainy season. We captured and ringed 89 individuals at the headquarters of the Açu National Forest. However, between January and the end of July 2021, we revived only 42 of them. In these resightings were nestlings and some adults. The consistent resighting of a few individuals together is a strong indication that they maintain a family group formation within the study area. Our results from monitoring individuals in the headquarters area of the Açu National Forest showed that individuals form relatively consistent groups over time. We also verified that individuals ringed as nestlings, in 3 different years, remained together during this period. With the co-occurrence records we built a general network, from which we derived sub-networks, with records in the dry season and another with the rainy season records. The general and dry season networks showed similar density values (0.41 and 0.42, respectively) and modularity (0.43 and 0.40, respectively), but very different from that obtained for the rainy season (0.14 for density and 0.67 for modularity). These results indicate greater connectivity between individuals in the dry season than in the rainy season. This is associated with higher resource availability in the rainy season, which is also amplified by the reproductive period of the species.

9
  • ADRIANA ALMEIDA DE LIMA
  • ATLANTIC FOREST PRIMATES: CLIMATE CHANGE, HABITAT AVAILABILITY AND REPRESENTATION IN CONSERVATION UNITS

  • Advisor : MIRIAM PLAZA PINTO
  • COMMITTEE MEMBERS :
  • GABRIELA LUDWIG
  • MARCELA GUIMARÃES MOREIRA LIMA
  • MIRIAM PLAZA PINTO
  • RAONE BELTRÃO MENDES
  • VANESSA GRAZIELE STAGGEMEIER
  • Data: Sep 26, 2022


  • Show Abstract
  • The redistribution of species as measured by climate change endangers biodiversity. Understanding the mechanisms that influence the spatial rearrangement of species is important to estimate the consequences of the new configuration on ecosystem functioning. In addition, it is ideal to understand how this spatial redistribution will affect the efficiency of protected areas in the future, since they are static elements in the landscape, unlike climate conditions. Here, we model the current and future climate suitability of primates from the Brazilian Atlantic Forest aiming: i) investigate how climate change will influence the distributions of Atlantic Forest primates; ii) to investigate the potential geographic changes in the different bordering regions of the Atlantic Forest primate species distributions; and iii) to assess the effects of climate change on the representation of primate species from the Brazilian Atlantic Forest in conservation units. Our results showed that climate changes expected up to 2100 may: i) reduce the climatically suitable distribution area for primate species in the biome; ii) provide contraction of the northern limit of species distributions, indicating that the distribution of species should shift to the south, even if there is no shift of the southern limit; iii) reduce the level of protection of species in conservation units in the biome, making the national system of Brazilian conservation units more inefficient in protecting primates. If urgent measures to mitigate climate change and forest regeneration of this biome are not taken seriously, it is very likely that some primate species will become extinct.

2021
Dissertations
1
  • FELIPE EDUARDO ALVES COELHO
  •   The effects of climate and geology in the diversification and ecology of Neotropical water frogs from Lithobates palmipes species group (Ranidae).

  • Advisor : ADRIAN ANTONIO GARDA
  • COMMITTEE MEMBERS :
  • ADRIAN ANTONIO GARDA
  • FERNANDA DE PINHO WERNECK
  • TAMÍ MOTT
  • Data: Feb 25, 2021


  • Show Abstract
  • Understand which factors caused species diversification is fundamental to know the history of life on Earth. The neotropics is one the richest regions and much remains to be known about the processes underlying diversification in this region. Central and South America formation was marked by dramatic geological and climatic changes. In this study, we tested the effects of geological and climatic changes on amphibian from Ranidae Family diversification in neotropics. In chapter 1, we tested if allopatric speciation due to geological changes, or ecological speciation due to new environments, played a main role in Lithobates palmipes group diversification. Using ancestral range estimative and phyloclimatic analysis, we found that L. palmipes group diversification is related to dispersal to new areas followed by climatic niche divergence, suggesting the prevalence of ecological speciation. In chapter 2, we tested the effects of the connections between the Atlantic and Amazon Forest on the diversification and ecology of the L. palmipes species through phylogeographic, phyloclimatic analyzes and niche modeling. L. palmipes comprises a species genetically structured by biome. Phylogenetic relationships, and niche modeling indicate the usage of northeast connection during the Pleistocene, which caused rapid niche divergence between groups in each biome. Despite the structure by biome, one of the mitochondrial lineages is composed by individuals from eastern Amazonia and the Atlantic Forest, while the other is composed by western Amazonia individuals. Based on our result, the diversification of the L. palmipes species group is the result of the interaction between geological and climatic changes in the Neotropics.

2
  • VAGNER LACERDA VASQUEZ
  • Climate change and forest cover for endemic primates of the Atlantic Forest

  • Advisor : MIRIAM PLAZA PINTO
  • COMMITTEE MEMBERS :
  • GUILHERME ORTIGARA LONGO
  • MIRIAM PLAZA PINTO
  • SIDNEY FEITOSA GOUVEIA
  • Data: Mar 8, 2021


  • Show Abstract
  • The Atlantic Forest covers approximately 130 million hectares and extends over the entire Brazilian coast. This biome is essential for conserving primates, the mammals with the largest proportion of endangered species. The main threats to these species are habitat loss and climate change. Here, we addressed two questions: (i) what the proportion of forest cover in the current and future expected geographic ranges of Atlantic Forest primate species is? and (ii) are the protected areas efficient in representing areas climatically suitable for primate species in the Atlantic Forest considering current and future climates? To answer the first question, we calculated the forest cover in the region unique of the current species geographic ranges, the intersection region between the current and future geographic ranges, and the region unique of the expected geographical range for species in the future. We compared the current and future climatic suitability for the Atlantic Forest primates within the protected areas to the second question. The current network of protected areas represents higher suitability values compared to species geographic ranges. There was a general reduction in the suitability values in future climate scenarios, which is possibly related to the savanization of tropical forests, and there was no difference between the suitability represented by protected areas and that in the geographic ranges. Regions of intersection between current and future geographic ranges and regions unique to the future showed a higher proportion of forest cover than regions unique to the current geographic range. This result was expected because of the already documented displacement of species from low altitudes areas to high altitudes areas, where there is a bias in the protected areas selection and the location of permanent preservation areas. Our results demonstrate that, although the protected areas are efficient in conserving more suitable areas in the present, there will be a reduction in areas climatically suitable for the Atlantic Forest’s primate species in the future. As a result, these species may need to disperse to more climatically suitable areas. Although most of the geographic ranges foreseen for the future for these species will be composed by matrix, which can make dispersion difficult, the areas of intersection between the current and future geographic ranges presented a greater forest coverage. This can make conservation efforts in these regions more efficient for species both at present and in projections of future climate change. To avoid the loss of these species, joint efforts are necessary to seek the maintenance, expansion, and management of protected areas, reduce the emission of greenhouse gases, incorporation the consequences of the climate crisis on biodiversity in conservation strategies, and guarantee policies public policies that prevent deforestation and restore deforested areas.

3
  • IANA TAVARES FAVERO
  • Habitat Suitability Patterns and Impacts for the American Manatee, Trichechus manatus, on the Brazilian Coast

  • Advisor : EDUARDO MARTINS VENTICINQUE
  • COMMITTEE MEMBERS :
  • RODRIGO HIPÓLITO TARDIN OLIVEIRA
  • EDUARDO MARTINS VENTICINQUE
  • GABRIEL CORREA COSTA
  • Data: Aug 27, 2021
    Ata de defesa assinada:


  • Show Abstract
  • The manatee, Trichechus manatus, is classified as an Endangered species in Brazil, with an estimated population of 1100 individuals and threatened by habitat loss and fragmentation. This study aimed to investigate the suitability of the habitat available for the species along the Brazilian coast, as well as the degree of cumulative impact. For this, an ensemble forecast was created from 120 habitat suitability models built using the BIOCLIM, Domain, Mahalanobis, GLM, Maxent and SVM algorithms, based on important environmental variables for manatee distribution. The suitability results obtained were used to build T. manatus potential distribution map and compared to the degree of cumulative impact observed in the coast of Brazil. Areas of low suitability for the species were found in the mouth of the Amazon River, and in parts of the coast of Maranhão, and Rio Grande do Norte. The areas of high suitability are more consolidated between the east coast of Ceará and the coast of Alagoas states, with patches of high suitability also on the coast of Piauí and Maranhão states. The southern limit of potential distribution observed was the Todos-os-Santos Bay, in the state of Bahia. Cumulative impact analyzes indicate that most of the high suitability areas are under low impact. It was also observed that the areas of high suitability and high cumulative impact are concentrated in the Northeastern Brazilian coast, especially close to the state capitals. Continuous patches of high cumulative impact were also observed from the Parnaíba River Delta to the Piauí-Ceará border, and along the entire coast of the state of Pernambuco. The results found in this study can help in the development of conservation strategies for the species along the entire coast of Brazil, supporting decision-making and the allocation of resources more efficiently.  

4
  • SAULO SIDARTA HENRIQUE DE BRITO
  • ASSESSMENT OF THE ADAPTIVE CAPACITY OF PEASANT COMMUNITIES IN THE BRAZILIAN SEMIARID TO CLIMATE CHANGE AND THE COVID – 19 PANDEMIC

  • Advisor : CRISTINA BALDAUF
  • COMMITTEE MEMBERS :
  • CRISTINA BALDAUF
  • PRISCILA FABIANA MACEDO LOPES
  • ANDRE BRAGA JUNQUEIRA
  • Data: Aug 30, 2021


  • Show Abstract
  • Global climate change is causing changes in many physical and biological systems at various scales and is also reflected in local livelihoods. In semiarid regions, the effects of climate change are associated with considerable increases in the levels of aridity, frequency and intensity of droughts. This scenario represents a great challenge for human populations that depend on the natural environment to carry out agricultural and livestock activities. Recently, the shock posed by the COVID-19 pandemic, combined with the rapid environmental changes that are taking place at local and global scales, may increase the vulnerability of local livelihoods and, consequently, reduce their resilience. Thus, the aim of this study is to understand the resilience of the livelihoods of semi-arid peasant communities in the face of impacts caused by global climate change and the recent COVID-19 pandemic. We seek to understand how adaptive capacity varies as a function of livelihood resilience as well as the agricultural model employed and the adaptive strategies adopted to deal with shocks. We conducted semi-structured interviews with peasant families residing in three rural settlements in Rio Grande do Norte and collected data on perceived changes related to climate and COVID - 19, its causative factors and possible adaptive measures, as well as quantifying the resilience of livelihoods, the family income (used to measure adaptive capacity) and the degree of agroecological transition. We use structured equation models and generalized linear models to test our hypotheses. Overall, both the resilience of livelihoods and the degree of agroecological transition were low. Our results showed a positive effect of livelihood resilience on adaptive capacity in the climate change scenario. The agroecological transition and adaptive strategies did not have a significant effect on adaptive capacity related to climate change. For the COVID – 19 scenario, none of the studied predictors had a significant effect on adaptive capacity. We also found a positive effect of the fruit growing activity and the size of the cultivated area on the adaptive capacity in the climate change scenario, however the same was not true for the COVID – 19 scenario. Our results may serve as a basis for actions aimed at increasing the resilience of socio-ecological systems in semiarid regions, as well as for the establishment of metrics for monitoring and evaluating interventions related to the stressors studied.

      

5
  • LARA CUNHA LOPES
  • Cetacean strandings, seismic surveys and environmental factors in the northeast of Brazil


  • Advisor : RENATA SANTORO DE SOUSA LIMA
  • COMMITTEE MEMBERS :
  • CAMILA DOMIT
  • CRISTIANO LEITE PARENTE
  • MARIA ISABEL CARVALHO GONÇALVES
  • RENATA SANTORO DE SOUSA LIMA
  • Data: Aug 30, 2021


  • Show Abstract
  • Cetaceans are highly dependent on sound for vital activities and have been negatively affected by anthropogenic noise, which can cause from behavioral changes to physical damage. Mass strandings have been linked to active sonars, which seem to mainly affect deep diving species. Another noise source of concern are seismic surveys (SS), an activity that uses airguns to generate high-intensity impulsive sound waves. However, the causal effect of seismic surveys on the mortality and stranding of cetaceans is still controversial. We examined the relationship between cetacean strandings and 3D seismic surveys in the equatorial northeastern Brazil, accounting for the confounding effects of some oceanographic variables. We gathered the strandings registered between 2000 and 2019 in the states of Ceará and Rio Grande do Norte and separated the species into 5 ecological groups according to its occurrence, size, and usual diving pattern. Then, we characterized the spatiotemporal occurrence of the strandings and selected two areas where the search effort was more consistent. For these areas, we analyzed whether SS and wind and wave conditions affected the occurrence and number of strandings of each ecological group. We also simulated the drift of mimic cetaceans considering a constant mortality rate inside seismic operations´ limits and compared the spatial distribution of these simulated landings to the observed strandings for the same period. In the 20 years considered, 351 strandings were recorded, including 22 species and 5 families. Stranding records were higher in summer, when tourist seasonality increases the surveillance of beaches, and increased along the years, which may reflect an increase in monitoring effort in response to environmental constraints from 2010 onwards. Seismic surveys also increased in coverage area and duration compared to operations of the first decade of compiled data. From the 65 strandings that occurred up to one week after an SS operation, 5 had pathological alterations compatible with gas embolism syndrome, which might be associated with exposure to seismic exploration activity. SS occurrence increased the strandings of oceanic species with shallow dive, despite oceanographical factors. The number of strandings of deep diving species as well as all species combined was also affected by SS occurrence, when considering specific wave states. Furthermore, 36% of the observed strandings positions overlapped with landings from simulated mortality inside seismic operational areas. Drift simulations showed that animals that could have died in SS of Ceará may beach in other states of Brazil and would go undetected by the current beach monitoring efforts. Areas with highest landing probabilities for animals that died within seismic operation areas may reach north well beyond the extension of beach monitoring programs required by the environmental regulation institution. We recommend that previous drift simulations are carried out as a requirement of the licensing process to determine which portion(s) of the coast should be monitored in beach monitoring projects. Results revealed that a portion of the animals reported were affected by seismic surveys while another large portion of affected animals would not be detected because of drift effects. Thus, the impact seen here is likely an underestimate of the actual impact of seismic surveys on the mortality and strandings of cetaceans in the region.

6
  • YOLANDA DE MACEDO DANTAS
  • Contribution of natural and artificial sources to the growth of marine shrimp Litopenaeus vannamei in low salinity

  • Advisor : JULIANA DEO DIAS
  • COMMITTEE MEMBERS :
  • JULIANA DEO DIAS
  • ELIANE MARINHO SORIANO
  • EVANILDE BENEDITO
  • Data: Aug 31, 2021
    Ata de defesa assinada:


  • Show Abstract
  • The natural productivity of a pond plays an important role in shrimp nutrition and in keeping the environmental quality during cultivation. Planktonic and benthic organisms as well as detritus are pointed out as the main nutritional sources for shrimp. This study evaluated the relative contribution of natural feed sources and commercial feeds to the growth of shrimp Litopenaeus vannamei on semi-intensive farms with low salinity water. The stable isotope analysis of carbon and nitrogen was used as a method to trace the sources in the animal's muscle tissue. The relative contributions were estimated through a mixing model using the isotopic signature of samples of shrimp, commercial feed, sediment organic matter, and seston, in addition to the discriminant factors of the sources. The results indicate that there was a pattern of increment in the contribution of the natural feed sources between the cultivation phases I (30 days) and II (60 days), but the main source for the development of the shrimp was the commercial feed. The natural sources had their greatest contribution (46.8%) in phase II under low stocking densities (Farm A) and the smallest contribution (26.9%) in phase II under high stocking density (Farm B). The difference in the relative contributions of the sources is also associated with nutritional characteristics of the commercial feed, the availability of natural food, and the environmental conditions. Increasing natural feed sources contributes to more sustainable low-salinity semi-intensive shrimp farming practices.

7
  • MAYARA LUÍZA ALVES PEREIRA
  • Morphology and ecological function of lenticels in woody species of the Caatinga dry forest

  • Advisor : GISLENE MARIA DA SILVA GANADE
  • COMMITTEE MEMBERS :
  • CLARISSA GOUVEIA FONTES
  • FELIPE PEREIRA MARINHO
  • GISLENE MARIA DA SILVA GANADE
  • JULIANA ESPADA LICHSTON
  • Data: Aug 31, 2021
    Ata de defesa assinada:


  • Show Abstract
  • Lenticels are pore-like structures, commonly originated in the substomatic cavity through a more intense meristematic activity of the phelogen. Unlike cork cells, which are tightly arranged and have suberified walls, lenticels are made up of cells with a rounded shape and delicate walls, a characteristic that allows for the presence of large intercellular spaces, which are directly related to the known functions of these structures. Lenticels are present in a variety of organs and species of terrestrial plants, presenting distinct adaptations that help individuals to establish themselves in the face of changes in the environmental conditions experienced. Although lenticels were described two centuries ago, there are many gaps in knowledge involving these structures. This dissertation  to clarify the importance of lenticels and understand how these structures occur in plant species from semiarid environments. The first chapter aims to carry out a literature review on lenticels in order to understand how different approaches and studies have been developed over time, also seeking to map specific fields of knowledge that still need to be filled. Specifically, we sought to: 1) Describe how lenticels occur in different phylogenetic groups of plants; 2) Describe in which plant structures the lenticels can be found; and 3) Describe the main functions that are given to lenticels. For this, we reviewed the specific literature through searches in scientific repositories, readings and cross-references. We found that lenticels are not exclusive to stems and roots, occurring in several organs, being present in species of “pteridophytes” (monilophytes), gymnosperms and angiosperms. In addition to gas exchange, lenticels perform other functions, such as water absorption, also serving as transpiration points. These structures can respond to environmental stressors, showing adaptations to the environment. Although knowledge about lenticels has grown over the years, there are still gaps to be filled, especially in arid and semi-arid climates, since most studies published to date deal with plant species from wet and humid environments. In the second chapter, we aim to describe the morphology of the lenticels and stem of 14 woody species from the Caatinga, in order to search for possible morphological patterns and separate them into functional types. Individual samples were collected for each species and histological slides were prepared for anatomical description. Additionally, lenticels were analyzed using electron scanning microscopy and fresh material under stereomicroscope for descriptions of external morphology. We found a difference between the morphological characteristics of the lenticels, as well as the general morphology of the stem. We also observed two patterns of structural changes and construction of occlusion layers in the lenticels, which indicates at least two possible strategies adopted by species adapted to semi-arid conditions, suggesting that the lenticels of plant species can evolve distinct characteristics in response to drought. The presence of occlusion layers can favor species in seasonally dry tropical forests, reducing transpiration rates and also allowing gas exchange in the absence of leaves in deciduous and semi-deciduous species in the dry seasons.

Thesis
1
  • LEONARDO CAPITANI
  • RESOURCE AVAILABILITY AND TEMPERATURE: NEW INSIGHTS FROM WESTERN ATLANTIC REEF ECOSYSTEMS

  • Advisor : RONALDO ANGELINI
  • COMMITTEE MEMBERS :
  • RONALDO ANGELINI
  • GUILHERME ORTIGARA LONGO
  • MARIANA BENDER GOMES
  • PAULO INÁCIO DE KNEGT LÓPEZ DE PRADO
  • RONALDO BASTOS FRANCINI-FILHO
  • SERGIO RICARDO FLOETER
  • Data: Apr 26, 2021
    Ata de defesa assinada:


  • Show Abstract
  • Reef ecosystems are complex, biodiverse and productive marine systems. Although they represent less than 0.09% of the surface of the oceans, these ecosystems provide fundamental ecological processes, such as nutrient recycling, feeding, reproduction and evolution of many species. In these ecosystems there are non-linear relationships between physical variables (temperature, acidity, salinity, dissolved oxygen) and biotic components (primary production and species abundance). On physical side, water temperature is a crucial factor that can affect the phenology, growth and trophic interactions of many reef species. On the side of biological interactions, it is known that the colonization of shallow waters by herbivorous fish may have facilitated the formation of reefs as we know them today, leading to specific changes in the trophic relationships of these environments. Surprisingly, there is a lack of general understanding on how temperature, resource availability and trophic interactions jointly shape reef environments in the western Atlantic Ocean. The study with a mathematical approach of the reef trophic interactions and their dependence on temperature and resource availability offers enormous potential for the consolidation of ecological theories or the discovery of new macro-ecological patterns. This thesis is organized in three chapters, in which we explore the relationship of temperature and available resources on reef species abundance in three different ways. In the first chapter, using a controlled field experiment on the reef of Rocas Atoll, we tested mechanistic models of the functional response of the fish Acanthurus chirurgus with its resource algae Digenea simplex. The results indicate that the herbivory process by A. chirurgus is best described by a model where the amount of algae and the density of A. chirurgus are equally important to define the per capita resource consumption. These results shed new light on the dynamics of herbivorous fish-algae interactions in the western Atlantic, highlighting the fundamental importance of considering the effect of consumer density on herbivore- plant models for reef ecosystems. In the second chapter, we modeled the food web of Rocas Atoll reef ecosystem and we analyzed the changes in standing biomass at all trophic levels as a response to the rise in sea water temperature over the 21st century, based on IPCC scenarios. The results of the simulations indicate that, by the end of the century, the total biomass of the ecosystem should decrease by 1%, 8% and 44% in low, medium and high emissions scenarios. As the total biomass decreases, the trophic structure of the ecosystem will change, favoring primary producers (algae turfs), invertivorous fish, while hard corals will severely decrease. In the third chapter, we will use data on reef fish length over 61° degrees of latitude in the Western Atlantic (from North Carolina, USA to Santa Catarina, Brazil). We will test for the existence of a linear relationship between the average fish body size, sea water temperature and resource availability (primary productivity). The results expected for this chapter (not yet finalized) should strengthen a general ecological rule: greater availability of resources, greater individual body size regardless of temperature. With this thesis, I hope to contribute to the construction of a more solid and general basis on the factors (physical and biological) that influence one of the most important biological processes in reef ecosystems: resource intake (predation) and the consequent conversion of resources into new living biomass.

2
  • CLARISSE CAROLINE DE OLIVEIRA E SILVA
  • Apparent survival of neotropical birds and factors related to their variation

  • Advisor : MAURO PICHORIM
  • COMMITTEE MEMBERS :
  • EDUARDO MARTINS VENTICINQUE
  • LEONARDO FERNANDES FRANÇA
  • Luciana Vieira de Paiva
  • MARIA ALICE DOS SANTOS ALVES
  • MAURO PICHORIM
  • MILENA WACHLEVSKI MACHADO
  • Data: Apr 27, 2021
    Ata de defesa assinada:


  • Show Abstract
  • Understanding factors related to birds’ life-history traits variation is essential to answer ecological and evolutionary questions. Studies about variations in life histories examine mainly the effects of limited food, predation, and climatic conditions. As a result of trade-offs, variations in life histories follow a ‘slow-fast tendency’ which ranges from high fertility and low survival to low fertility and high survival. Thus, tropical species tend to invest more in self-maintenance than in current reproduction, while species from temperate zones do the opposite. Tropical environments are considered to be less seasonal and have high food resource stability. However, this information is based essentially on humid tropical environments. Pondering these knowledge gaps about Neotropical environments, we aimed to verify the applicability of these pre-established standards regarding the Neotropical birds’ life history. We gathered a field database from 15 sample areas plus 11 more areas from literature data. In this thesis, we used survival estimates from 327 populations, of which 147 were unpublished estimates and 180 estimates from the literature. Field collections took place at different times between 1999 and 2019. The sampling time in each area ranged from 2 to 20 years. The sampling areas covered latitude variation from 20º N to 34º S. We used survival estimates of environments with different intensities of climatic seasonality to test the hypothesis of a relationship between climatic seasonality and survival. The survival values found were similar throughout South America, indicating that other factors may act more intensely on the survival variations of these birds. Our results suggest that the seasonality conditions in South America are not intense enough to reflect on the species survival. Behavioral and physiological changes may mitigate the extrinsic mortality of adults. Furthermore, the young high mortality rates suggest that birds from seasonal tropical environments also favor residual reproductive investment through strategies that guarantee greater survival expectancy for individuals.

3
  • MILENA CORDEIRO DE AMORIM LOPES
  • RETHINKING ECOLOGICAL RESTORATION THROUGH THE LENS OF CLIMATE CHANGE AND EARLY WARNING SIGNALS OF DESERTIFICATION

  • Advisor : GISLENE MARIA DA SILVA GANADE
  • COMMITTEE MEMBERS :
  • CRISTINA BRANQUINHO
  • CARLOS ROBERTO SORENSEN DUTRA DA FONSECA
  • FELIPE PIMENTEL LOPES DE MELO
  • GISLENE MARIA DA SILVA GANADE
  • MIRIAM PLAZA PINTO
  • Data: Apr 30, 2021
    Ata de defesa assinada:


  • Show Abstract
  • Caatinga contemplates a great amount of biological diversity and ecosystem services and functions as an important carbon sink. However, this biome is among the most sensitive regions of the globe to climate variations and presents environmental conditions and anthropic actions that diminish its resilience. This work intends to: 1) Identify early warning signals for changes between vegetated and desertified states and indicate priority areas and emergency actions for restoration, improving the return on investments in restoration and combating desertification 2) Create guidelines that guide a sustainable forest restoration based on changes in composition by loss, gain and replacement of species in the face of expected climate changes; and 3) Provide lists of species that can be planted today and that will resist climate change for 1,112 municipalities on an interactive website, connecting the modeling results to decision makers and the general population. For chapter one we use a 20-year time series of Enhanced Vegetation Index (EVI, 2000-2019) data, calculate the residual autocorrelation (critical slowing down) and the linear trend of the time series to identify whether the system tends to recover or collapse in terms of vegetation cover. 8.77% of the Caatinga has been approaching a critical transition point and, that of this amount, 66,121 km2 showed a tendency for recovery and a 7,938 km2 for vegetation cover collapse. Both recovery-prone and collapse-prone sites are concentrated in areas of natural vegetation, indicating that few degraded areas are tending to recover and that many areas of natural vegetation are tending to lose important ecosystem services. We believe that all of these areas need forest restoration, either by passive or active restoration within each level of urgency. For chapter two and three we built climate suitability models for the present and for the future (2050) for 606 Caatinga woody species. In chapter two we identified areas of species gain, species loss and areas where there will be species substitution, in order to suggest guidelines for restoration in the face of future climate change. We foresee 28.5% of the species will present geographical area expansion, 71.5% reduction and 0.5% will suffer extinction for the whole Caatinga territory. Local extinctions, on the other hand, occur in 88.9% of the regions, with only 11.1% of the Caatinga areas gaining species. Scenarios of species loss and high species turnover were registered, which makes the restoration planning much more challenging. Besides these scenarios, others were analyzed adding six combinations of changes in composition that require different guidelines for the sustainable practice of ecological restoration. The restoration guideline for each scenario was based on the following questions: 1) which restoration method to prioritize (spontaneous restoration or planting?); 2) when to invest in the maintenance of adjacent conservation units due to the future need for source areas?; 3) which species to plant and where to plant threatened species restricted to the biome in the face of the expected climate change? In chapter three, we detected the change in species richness in 1,112 municipalities, created 1,112 lists with the species that will best respond to the predicted climate change for each municipality, published the lists on an interactive map-based website, and finally schematized this workflow so that this method can be applied in other areas of the world. We predicted that of the 1,112 Caatinga municipalities, 809 showed a reduction in species richness, 286 gains, and 17 maintenance. Even in the municipalities where the balance was positive, a loss of species may have occurred at the same time that a greater number of other species were gained through colonization. Therefore, all regions to be restored need local investigations for the appropriate choice of species, and this information should be accessible to decision-makers and the general population. Our interactive website is an example of how to bring the scientific production of modelers closer to the practical needs of companies and people who need to implement restoration projects. This is because with just a cell phone connected to the internet the user can get a list of species that can be successfully planted in his municipality and that will survive future climate change. This diffusion of information can create a large-scale sustainable restoration project in the medium and long term. 

4
  • JOÃO PAULO TAVARES DAMASCENO
  • SHOREBIRDS CONSERVATION IN BRASI: UNDERSTANDING THE PRESENT, KNOWING THE FUTURE

  • Advisor : MAURO PICHORIM
  • COMMITTEE MEMBERS :
  • ANDERSON GUZZI
  • ANDROS TAROUCO GIANUCA
  • ANGELICA MARIA KAZUE UEJIMA
  • GUILHERME ORTIGARA LONGO
  • MAURO PICHORIM
  • Data: Apr 30, 2021
    Ata de defesa assinada:


  • Show Abstract
  • Shorebirds are considered one of the most impressive groups of birds due to their long migratory movements between breeding and wintering sites located in wetlands, and sometimes located in different hemispheres. This complex movement associated with the great diversity of habitats used by species during migration also implies threats at different scales, and a challenge for conservationist policies that prioritize the protection of wetlands. Despite international efforts and the creation of a national instrument for the conservation of the group, few protection areas have been implemented. To assess information on patterns of richness, distribution, movements and how species will respond to climate change in the future, we have developed the present thesis in two chapters. In chapter 1, we assessed patterns of distribution, movement, and richness of 28 migratory and resident shorebirds species along Brazilian wetlands, using the kernel density method and generalized additive models. Our results revealed two distribution patterns assessed by the projections of the kernel estimates: some species occurred more widely distributed, mainly along coastal and inland areas, and another species with more restricted records, mainly along the coastline. These data also show movement patterns that varied for species, with some migrating only along the Atlantic flyways, others using both flyways (Atlantic and Central flyways), and some species using both. For the models, the best candidate model explained 97% of the data and it was influenced by the agricultural, forest remnants, urbanism, beaches and dunes and non-forested natural areas, the first two negatively affecting the shorebirds richness and the last three positively. In chapter 2, we used spatial predictors of climate, energy, and habitat heterogeneity to test which hypothesis best explains the patterns of shorebird richness in Brazil. We identified a negative relationship between species richness and the variation between maximum and minimum temperatures, indicating that more climatically stable environments are associated with higher levels of richness in the shorebirds group. In Chapter 3, we combined occurrence records with climate, topography and land cover data, to model the habitats availability of resident and migratory shorebirds in Brazil, and to identify how their habitats will be affected in future forecasts of different scenarios of carbon concentration (RCP 4.5 and RCP 8.5). Our results showed that both RCP’s scenarios indicated a balance of losses greater than that of gains, with most predicted species losing more than 50% of their projected habitats for 2050 and 2070. Still, using binary maps produced through estimates for each species, our projections revealed important areas located along the southeast, north and south coast of the country, regions in the Pantanal and along the Amazon River, which are also expected to suffer severe habitats losses in the future. In chapter 3, we will combine occurrence, climate, and marine variables to discuss the predictors preferred by species when choosing their sites along the coast, and how richness varies across these environmental gradients. Our study integrates additional information on distribution, movements, and shorebirds richness, in addition to future perspectives on the consequence of global warming in the habitats used by shorebirds in Brazil. These results raise the urgent need to implement measures to control impacts on semi-anthropized habitats, protection and better management of wetlands and implementation of sustainable policies.

5
  • PRISCILLA RAMOS CRUZ
  • More than species aggregations: the importance of biodiversity facets in natural and anthropogenic contexts for marine ecology and fisheries

  • Advisor : ADRIANO CALIMAN FERREIRA DA SILVA
  • COMMITTEE MEMBERS :
  • ADRIANO CALIMAN FERREIRA DA SILVA
  • JOSE LUIZ DE ATTAYDE
  • PRISCILA FABIANA MACEDO LOPES
  • RAFAEL DETTOGNI GUARIENTO
  • ROSEMBERG FERNANDES DE MENEZES
  • Data: Jul 30, 2021
    Ata de defesa assinada:


  • Show Abstract
  •       The facets of biodiversity (i.e., taxonomic, functional and phylogenetic) are essential to ascertain the functioning and changes in ecosystems. The objectives of this thesis were: 1) to understand how studies with facets developed in Ecology; 2) how the facets relate to each other and respond to different forms of anthropogenic impacts; 3) changing your patterns over time. In chapter 1, we assess the development of studies aimed at functional and phylogenetic diversity in Ecology. There was a predominance of terrestrial environments with plants and incipience for aquatic environments and vertebrate organisms, both in temperate and tropical regions. This is the area that has developed the most in Ecology in recent years. In the second chapter, we investigate the effects of commercial fishing (i.e., artisanal and industrial) on the taxonomic and functional composition of Brazilian fish. Seven attributes with ecological and fishing importance were adopted to estimate fish richness, divergence and functional evenness. As fishing descriptor variables, total annual catches and the diversity of industrial fishing methods were used. Taxonomic richness and evenness were also used as predictors of functional diversity and as responses to fishing. Through structural equation models (SEMs), different types of association between all predictor and response variables were verified. Thus, we observed that in artisanal fishing, the variable most sensitive to decreases promoted by the increase in catches and increases in taxonomic evenness or richness was functional divergence. This indicates that the capture of a greater number of species in this modality may be causing the obtainment of species closer to each other, which has come to dominate the composition, reducing the functional diversity of the fish. On the other hand, catches also increased functional evenness, making this the variable most positively associated with fishing. While functional richness was not directly related to fishing, it responded strongly to taxonomic richness. In industrial fishing, the diversity of methods provided increases in divergence and functional evenness, while the catches acted in the opposite direction, showing that the increase in catches tends to result in a lower occurrence of dissimilar species, similarly to what occurs in fishing handmade. While the diversity of methods, amplifies the effects of fishing, resulting in obtaining a more diverse and less dominant fish. In chapter 3, an analysis of the beta-functional and taxonomic diversities of the Brazilian marine fish was carried out, in order to identify the phenomenon of homogenization in the Brazilian marine fishery, through the tendency to always capture the same characteristics or species within each modality of fishing, regardless of location. As a result, we observed that industrial fishing presented greater total beta-taxonomic diversity than artisanal ones, with less richness and greater beta-taxonomic substitution, showing an unexpected symptom of homogeneity for subsistence fishing. The total beta-functional was higher for artisanal fishing, as well as the beta-functional richness, showing heterogeneity for this fishery. Beta-functional substitutions were more present in industrial fishing, confirming the hypothesis of homogenization of Brazilian fish.


6
  • FELIPE DE OLIVEIRA FERNANDES
  • Seaweed structural complexity and chemical composition as structuring factors of the associated fauna

  • Advisor : ELIANE MARINHO SORIANO
  • COMMITTEE MEMBERS :
  • ELIANE MARINHO SORIANO
  • JULIANA DEO DIAS
  • EDSON APARECIDO VIEIRA FILHO
  • THELMA LÚCIA PEREIRA DIAS
  • VINICIUS PERUZZI DE OLIVEIRA
  • Data: Jul 30, 2021
    Ata de defesa assinada:


  • Show Abstract
  • Seaweeds play several roles for associated fauna (shelter from predation and/or stressful abiotic conditions, substrate, food and sediment retention). In this context, this work was divided into three chapters to investigate how the structural complexity of different seaweeds may affect ecological aspects of the associated fauna (richness, density, diversity and composition) and which role seaweed complexity and chemical composition play on habitat and food choice by their fauna as well as predation. In the first chapter, the influence of seaweed structural complexity was analyzed based on ecological aspects of the fauna associated with six species of seaweeds. The ecological aspects were evaluated considering the fractal area (spaces between branches), the fractal perimeter (contour level) and the volume of seaweeds. Halimeda opuntia had the highest values of richness and diversity. Dictyopteris delicatula harbored the highest density. Regarding faunal composition, H. opuntia and Gelidium coarctatum had the most distinct communities. In the second chapter, experiments were carried out to assess the choices (food, habitat and chemical cues) by amphipods concerning different species of seaweeds. Gracilaria cervicornis was the most consumed seaweed among the species offered. Moreover, in the experiments of chemical cues (mimics with and without algal extracts), the amphipods were attracted only by those with extracts of G. cervicornis. These results indicate that amphipods are likely attracted by chemical cues from G. cervicornis as they serve primarily as a food source. In the third chapter, experiments were carried out to determine whether the seaweed choice by amphipods is influenced by predators based on chemical cues. The amphipods preferred D. delicatula cues over G. cervicornis and G. coactatum cues, but switched their choice to G. cervicornis when predator cues were added to D. delicatula cues and remained in G. cervicornis even when predator cues were added compared to G. coarctatum cues. These results demonstrate that, although they prefer some seaweeds, amphipods are able to adapt their behavior based on predator chemical cues.


7
  • SÁVIO ARCANJO SANTOS NASCIMENTO DE MORAES
  • THE CARCINIZATION PROCESS AS A MEDIATOR TO SEXUAL DIMORPHISM AND MORPHOMETRIC VARIATIONS CLINES: ECOEOGRAPHY IN DECAPODA

  • Advisor : FULVIO AURELIO DE MORAIS FREIRE
  • COMMITTEE MEMBERS :
  • FULVIO AURELIO DE MORAIS FREIRE
  • ALLYSSON PONTES PINHEIRO
  • ARIÁDINE CRISTINE DE ALMEIDA
  • LUCIANO DE FREITAS BARROS NETO
  • PAULO AUGUSTO DE LIMA FILHO
  • Data: Aug 12, 2021
    Ata de defesa assinada:


  • Show Abstract
  •   Decapoda can have a variety of body shapes, elongated for superb swimming, asymmetrical, or symmetrically compressed with a hard shell. These are named as: ‘Shrimp-like’, ‘Lobster-like’, ‘Squat-lobster-like’, ‘Pagurus-like’ and ‘Crab-like’, which represent convergent morphotypes in different phylogenetic lineages. This process is known as Carcinization, a series of modifications associated with the occupation of vacant benthic niches in a past scenario. Adaptive convergence processes within the taxa are poorly investigated, and their macroscale mechanisms, such as the Rensch (the correlation of sexual size dimorphism) and Bergmann (positive relationship between mean body size and latitude). Thus, through regressive models with data obtained from a systematic review and collected data (evaluated by the geometric morphometry tool – the information: Centroid Size, Form and Shape) describe/understand the ecomorphological rules. In addition, the variation in body shape was evaluated for interpopulation comparison between species of the same morphotypes. The revised Crab-like families showed a male-female size ratio following the neutrality of Rensch's Rule. The magnitude of sexual dimorphism (DS) of size and size of females showed neutrality of the Rensch Rule. Between Average population size and latitude, there was a tendency to corroborate the Bergmann Rule. And in the DS relation of size and latitude, neutrality was visualized. Information involving magnitude as a response variable (Centroid SD, Shape SD and Form SD) showed similar results both in general models and in trends for each morphotype, the proposed inverse of the Bergmann Rule. Ectotherms have a metabolic limitation based on balance body size, metabolic rate amplitude and optimal thermal rate. The Rensch-Bergmann interaction is a clinal approach to the Rensch’s rule. This suggests that some traits vary systematically with latitude, with Rensch's Rule being visualized in its degree of magnitude among populations and its general trend in the species or lineages in question. Overall, trends in different directions were evidenced, but the sign between morphotypes was not always conclusive. The morpho-space variations showed that morphotypes tend to unify morphometric variations. The vector displacement energies of the 'evolutionary homologies' show an action not always in the same direction, but its variation was noticeable between the axes and in the same structures for each group.   


8
  • MARCIO LUIZ FARIAS RATO
  • Local Ecological Knowledge associated with family farming in Agreste Potiguar

  • Advisor : JOSE LUIZ DE ATTAYDE
  • COMMITTEE MEMBERS :
  • JOSE LUIZ DE ATTAYDE
  • MALCON DO PRADO COSTA
  • MICHELLE CRISTINE MEDEIROS JACOB
  • JOSÉ LUIZ ALVES SILVA
  • ULYSSES PAULINO DE ALBUQUERQUE
  • Data: Nov 12, 2021


  • Show Abstract

  • Local Ecological Knowledge (LEK) is increasingly important within science to discuss the conservation of biological resources and ecosystem processes. Here in this thesis, we describe how LEK contributions and potential for building hypotheses in ethnobotanical use, phylogenetic structuring within the optimization of use and for the rescue of biocultural memory; and the insight to assess ecosystem services. The initial objective of the thesis is the Local Ecological Knowledge of the relationship between farmers and wood and medicine plants, filling a gap in ethnobotanical work in the Agreste Potiguar region. Within this first main objective, we have specific questions: 1) What are the social characteristics associated with the most specialized informants in the use of wood from the analysis of phylogeny? 2) How is the pattern of species dispersion along the phylogeny created from the knowledge of farmers for various diseases distributed over 11 parts of the human body system and 10 morphological structures of the plants mentioned? The second main objective is to know two parts, in the way of life of the communities they perceive the Local Ecological Knowledge. For the specific purpose of this second part, we will classify as consensus analyses for four classifications associated with ecosystem services. The results show that there are patterns of dispersion within the ecophylogeny of the species built from the citation of family farmers in the rural region of the state for wood and medicinal uses. Within medicinal uses, plant morphological structures tend to form a more phylogenetic pattern than human body systems. Regarding the perception of ecosystem services, both agricultural and environmental actors have different perceptions about the immaterial mechanisms associated with conservation and Local Ecological Knowledge. We ask the actors, researchers associated with conservation and the rural world to respect and guarantee all the rights included so that the Indigenous Community of Catu, perhaps the only one within this rural territory, can reproduce its activities and ways of life, because it is around this territory that farmers cite more species associated with biocultural memory.

2020
Dissertations
1
  • ANA ELIZABETH BONATO ASATO
  • Controlling factors of litterfall phenology and its effects on ecosystem multifunctionality in a semideciduous tropical forest


  • Advisor : ADRIANO CALIMAN FERREIRA DA SILVA
  • COMMITTEE MEMBERS :
  • ADRIANO CALIMAN FERREIRA DA SILVA
  • ALEXANDRE FADIGAS DE SOUZA
  • LEONARDO HENRIQUE TEIXEIRA PINTO
  • Data: Feb 5, 2020


  • Show Abstract
  • Plant phenology is modulated by biotic factors, such as interactions between species and the effects of biodiversity, and abiotics, such as factors related to water and thermal regulation. The effect of these factors on phenology generally depends on the intensity of environmental filters. Here, we test the importance of biotic and abiotic factors for the functioning of the tropical forest ecosystem, known as Restinga, under adverse conditions. Seeking to understand the temporal patterns of the forest, we tested the seasonality of leaf, branches and reproductive phenologies of the forest, exploring the relationship between these phenophases and possible abiotic guides (Chapter 1). All phenophases presented seasonality, being the phenology of reproductive materials the most seasonal. Leaf phenology was negatively guided by precipitation and relative humidity, and positively by insolation. The phenology of reproductive material was guided by the relative humidity of the air, while that of branches was affected by the wind speed. Given their important contribution of matter and energy to the ecosystem, as well as the possible biotic effects on phenology, we aimed to understand the importance of plant diversity for leaf phenology seasonality (Chapter 2). Through path analysis, we observed that species richness negatively affects seasonality and niche overlap, but that niche overlap has no effect on seasonality. In addition, soil K content had a positive effect on seasonality. The results indicate that the dominance, possibly maintained by K, guides the phenological pattern of species rich plant assemblages. Because ecosystem valuation is based on its ability to maintain multiple functions simultaneously, we aimed to understand the role of diversity (taxonomic, functional, and phylogenetic) and various abiotic factors in multifunctionality (Chapter 3). We also used weighted diversity metrics, given that dominant species could possibly have higher effects on multifunctionality. Using path analysis, we observed that multifunctionality was mainly determined by abiotic factors such as rainfall, slope and soil K content. In addition, model selection indicated those models with weighted metrics as best. Our results indicate that the environmental filters on the vegetation are intense, leading to seasonality of litter supply. This masks the biotic effects that, when present, occur through dominance, possibly guided by K.

2
  • LOUIZE FREYRE DA COSTA CORREIA
  • 3-D MONITORING OF CORAL HEALTH: COMPARISONS BETWEEN COASTAL AND OCEANIC REEFS

  • Advisor : GUILHERME ORTIGARA LONGO
  • COMMITTEE MEMBERS :
  • BÁRBARA SEGAL RAMOS
  • GUILHERME ORTIGARA LONGO
  • JULIANA DEO DIAS
  • Data: Feb 18, 2020


  • Show Abstract
  • Due to their proximity to more populated areas, coastal reefs may be potentially more prone to the effects of anthropogenic impacts compared to oceanic reefs. In these environments, corals can respond more quickly to these impacts, with changes in their health status, depending on the species and environmental variables such as depth, temperature and exposure to light. Comparing the health of corals in coastal and oceanic environments, within the same latitudinal range, can provide information on how anthropogenic impacts and the natural dynamics of the environment affect these ecosystems. We monitor colonies of the Siderastrea stellata (~ 5m deep) and Montastraea cavernosa (~ 30m deep) corals on coastal (Rio Grande do Norte; ~ 5 ° S) and oceanic (Fernando de Noronha; ~ 3 ° S) reefs in northeastern Brazil. In these places, the species monitored are among the main coral reef builders. We monitor quarterly for one year (2018-2019), using three-dimensional models generated by photogametry. From the generated models, we evaluated coral health indicators (bleaching, mortality, diseases and algal overgrowth). Both monitored species showed good health in coastal and oceanic reefs throughout the year, with no record of intense bleaching during the monitored period. In one of the oceanic reef environments, we observed periods and greater bleaching related to the natural dynamics of this environment leading to the burial of the colonies. Colonies of S. stellata remained in general healthier in coastal areas than in the oceanics, which may be related to less exposure to light in coastal areas compared to ocean reefs due to greater water turbidity. The health status of M. cavernosa was stable and, despite having differences between coastal and oceanic areas, the corals in all monitored sites had, on average, 80% of their surface in a healthy state. The surface water temperature was also similar and relatively constant in coastal and oceanic reefs. Coral health was more affected by variations in the local ecosystem (e.g. natural burial) than by proximity to human impact, indicating that local temporal dynamics need to be considering when assessing the response of corals to human impacts.

3
  • FERNANDA LAMIN HENRIQUE
  • Spatiotemporal patterns of vegetation productivity in Caatinga drylands

  • Advisor : EDUARDO MARTINS VENTICINQUE
  • COMMITTEE MEMBERS :
  • CARLOS ROBERTO SORENSEN DUTRA DA FONSECA
  • EDUARDO MARTINS VENTICINQUE
  • THIAGO SANNA FREIRE SILVA
  • Data: Feb 18, 2020


  • Show Abstract
  • Ecosystem patterns of vegetation are well related to climatic factors in seasonal environments. Rainfall is a limiting resource in arid environments, but there is evidence that in the absence of precipitation, geographic aspects such as land and climate factors as water balance, contribute to the stabilization of primary productivity. Using geoprocessed data, we tested the influence of altitude, water deficit and type of vegetation (forest formation, countryside formation and savanna formation) on primary productivity and on the stability of this ecosystem function in the Caatinga domain. We expect that altitude will positively influence both primary productivity and stability, while the water deficit will have a negative effect. We believe that forest regions depend more on the increase in elevation, while the herbaceous-shrub physiognomies are more strongly controlled by the water deficit. We map the Caatinga in greater and lesser productivity and stability, based on the division by the median, and, we modeled the temporal structure of these changes seasonally, through a cross correlation function, to verify how stable the Caatinga is. The influence of altitude and water deficit on primary productivity differ individually according to the type of vegetation. Still, we found a variation between different types of vegetation, the effect on stability, when altitude and water deficit interact with each other. The water deficit negatively affects primary productivity and stability, and appears to have a greater influence than altitude, which acts with a positive effect. The most productive and stable areas, which in the long term, make up 37.5% of the Caatinga, declines to 10% in October, on a seasonal scale. The strongest change happens almost instantly due to the decrease in places with higher productivity due to drought, showing that few areas remain stable in the most critical periods. Understanding which processes influence the patterns described are important in terms of conservation, to predict the places that may suffer the most from the changes that the Caatinga have faced in changing land use and climate

4
  • TALES MARTINS DE ALENCAR PAIVA
  • Insect herbivores and outcrossing rate in seed plants

  • Advisor : CARLOS ROBERTO SORENSEN DUTRA DA FONSECA
  • COMMITTEE MEMBERS :
  • CARLOS ROBERTO SORENSEN DUTRA DA FONSECA
  • GUSTAVO BRANT DE CARVALHO PATERNO
  • VANESSA GRAZIELE STAGGEMEIER
  • Data: Feb 19, 2020


  • Show Abstract
  • Evolution of plant mating system, such as selfing and outcrossing ways, is an intriguing question in plant biology, since that can suffer influence of several ecological factors. The Red Queen hypothesis suggests that biotic interactions parasite-host-like is the major factor driving the evolution and persistence of sexual reproduction in nature. Therefore, in light of this hypothesis, is expected that species under high pressures of natural enemies, present high investment in sex, that in plants it can be measurement by the outcrossing rate, a metric based in molecular markers. There are support for Red Queen for several groups of animals, however in plant kingdom this hypothesis remains underexploited, especially using comparative approaches. Here, our main objective was test if the evolutionary pressure of insect herbivores is effective in predict outcrossing rates in seed plants. For that, we fitted phylogenetic regressions using two independent datasets for these two variables, also including some vegetative covariables: life span, growth form, specific leaf area and maximum height. The regressions were performed under two alternative evolutionary models: Brownian Motion and Ornstein-Uhlenbeck. We also tested the Red Queen prediction for natives and exotics species, to analyze the role of the coevolutionary time between plant and herbivores in mating system driving. We found, in both models, that plant species under higher pressure of insect herbivores richness had higher outcrossing rates. The same pattern remains in native species but not in exotics. In the same line, we found that tall and longer-lived plants tend to be higher outcrossing rates than small and short-lived. These results are in accordance with the expected by the Red Queen hypothesis, supporting the still scarce empirical framework of macroevolutionary studies about the role of natural enemies on evolution of mating system in seed plants.

5
  • JESSICA BLEUEL
  • CORALS IN MARGINAL REEFS FACING GLOBAL CLIMATE CHANGE: FUTURE PROJECTIONS AND VULNERABILITY HOTSPOTS

  • Advisor : GUILHERME ORTIGARA LONGO
  • COMMITTEE MEMBERS :
  • MIGUEL MIES
  • GUILHERME ORTIGARA LONGO
  • MIRIAM PLAZA PINTO
  • Data: Feb 20, 2020


  • Show Abstract
  • Global climate change is a major threat to coral reefs around the world, increasing the annual frequency and severity of bleaching events, causing loss of living coral cover, complexity and diversity of coral reefs. Repeated and intense bleaching events can reduce the thermal tolerance and recovery capacity of coral species, so corals will likely depend on refuges in areas that will become more suitable as ocean warms (e.g. extratropical reefs), that are less impacted by increasing temperatures (e.g. deeper reefs) and where local human impacts are minimized, potentially enabling acclimation and adaptation. Therefore, identifying potential refugia and the most vulnerable areas to coral bleaching is critical to minimize local impacts and enhance coral´s ability to cope with climate change. We used Bayesian Hierarchical Spatial Model to project coral occurrence, cover and bleaching probabilities along the Brazilian coast that harbors the largest and richest marginal reefs in Southwestern Atlantic, and predicted how these probabilities are likely to change by 2050 and 2100, based on the RCP8.5 scenario forecasted by the Intergovernmental Panel on Climate Change (IPCC). By overlapping these predictive models, we identified the most vulnerable areas to coral bleaching (hotspots) under current and future scenarios. We identified higher coral occurrence and cover probabilities in tropical than subtropical regions of the Southwestern Atlantic. By 2050 and 2100, the projections indicate an increase in coral occurrence and cover probabilities toward extratropical and deeper offshore reefs, which could act as refugia. However, the role of these areas as refugia also depend on the bleaching probability, which tend to increase in future projections, and on the synergic effects of other anthropogenic impacts. The vulnerability hotspots were concentrated around the Abrolhos Bank, the largest and richest coral reef area in South Atlantic, both in current and future projections. This area comprises a network of marine protected areas that should be reinforced to mitigate local impacts and enhance the ability of corals to cope with increasing temperatures. The combination of these modelling approaches can be a powerful tool to inform conservation actions to face global climate changes accounting for future range expansion and increase in bleaching probabilities.

6
  • KELLY YUMI INAGAKI
  • Trophic interactions will expand their distribution and decrease in intensity under climate change

  • Advisor : GUILHERME ORTIGARA LONGO
  • COMMITTEE MEMBERS :
  • GUILHERME ORTIGARA LONGO
  • EURICO MESQUITA NOLETO FILHO
  • MARIANA BENDER GOMES
  • Data: Feb 20, 2020


  • Show Abstract
  • Tropical ecosystems harbor higher biodiversity, more intense and diverse ecological interactions than extratropical ecosystems. These latitudinal patterns result from long-term evolutionary processes, but the fast expansion of tropical species polewards due to climate change is altering biodiversity and interaction patterns. Tropicalization events have been identified for many marine organisms, including reef fishes, but the effects of climate change on large-scale patterns of species interactions are still poorly understood. Reef fishes area a good model to investigate these changes because they are critical consumers in reef ecosystems throughout latitudes, whose large-scale patterns of diversity and interactions are well understood. Because temperature affect the physiology of organisms, particularly ecthoterms, we hypothesized that (i) future warming of extratropical zones may intensify trophic interactions and enable tropical species to establish new interactions in these areas; and that (ii) increasing temperatures predicted for the near future would intensify trophic interactions in the tropics, up to the physiological limits when interactions would be no longer viable. This is the first study to evaluate how trophic interactions of different trophic groups (herbivores, invertivores and omnivores) will respond to increasing temperature scenarios. We used data on reef fish occurrence, biomass and patterns of fish trophic interaction on the benthos across 61° of latitude in the Western Atlantic, and applied Bayesian models to predict the intensity of interactions in 2050 and 2100 based on the Intergovernmental Panel on Climate Change (IPCC) scenarios. Trophic interactions will decline between 50-100% in the tropics, likely indicating that increased temperatures will exceed the physiological thermal tolerance of fishes. In the Northern hemisphere, from 20°N to 40°N, interactions will increase about 100%, likely due to tropicalization of herbivorous fishes and marine currents northward. This phenomenon was not observed in the Southern hemisphere. Interactions by invertivores will decline between 5-100% along Western Atlantic, indicating they may have a narrower thermal tolerance. Interactions by omnivores will decline about 100% at northern and about 30% at southern extratropics, but are likely to increase about 5-20% in the tropics, which could result from their feeding plasticity adaptations to different temperatures. Alternatively, fish can adapt and acclimate to changes in environmental conditions, but if there will be enough time for that to happen is still unclear. Predicting how climate change will affect trophic interactions may help understanding the future of ecosystems and the services they provide.

7
  • MERY INGRID GUIMARÃES DE ALENCAR
  • Generalities of priming effect: evaluating the effects of interactions between flowers and leaves

  • Advisor : ADRIANO CALIMAN FERREIRA DA SILVA
  • COMMITTEE MEMBERS :
  • ANDRÉ TAVARES CORRÊA DIAS
  • ADRIANO CALIMAN FERREIRA DA SILVA
  • ANDROS TAROUCO GIANUCA
  • Data: Feb 20, 2020


  • Show Abstract
  • The interaction between litter with different qualities generate non-additive effects on the decomposition, a phenomenon called priming effect (PE). Despite the global relevance of PE in decomposition, generalizations are still poorly understood, especially in tropical environments. The PE studies are concentrated on leaf litter and rhizosphere, but litter with higher chemical quality, such as flowers, can affect the dynamics of nutrient cycling at local and regional scales, producing mineralization hotspots. The PE relevance could be greater in tropical environments, as leaf litter is nutritionally poor and the interaction with higher quality litter can increases the magnitude of the phenomenon. Thus, this dissertation addresses, in two chapters, the relative importance of effects of floral and leaf detritus on the occurrence, magnitude and direction of the priming effect. In the first chapter we seek to understand the effects of the priming effect at the intraspecific level. For this, we conducted experimental tests with mixtures between floral and leaf litter, for 30 species with wide phylogenetic distribution. The interaction between litter resulted in non-additive effects for most treatments, with synergistic and reciprocal interactions for 53% of the species. The second chapter we aim the relative effect of intra and interspecific variation and their interactions on the magnitude of the priming effect. For this we use an experimental approach with floral and leaf litter of three species decomposing individual and mixture in all pairs of possible combinations, both intra and interspecific. Floral litter showed higher concentrations of important attributes for decomposition, which resulted in higher decomposition rates compared to leaf litter (F=197.4, p<0.0001). Functional differences between types of litter bring synergistic effects on decomposition, for most treatments with interaction between flowers and leaves. The greater magnitude occurring in interspecific interactions than intraspecific interactions. Despite the widespread occurrence of non-additive effects, we found no relationship between the magnitude of PE and functional dissimilarity in either chapter. Possibly the absence of a relationship between magnitude and functional dissimilarity is a result of the non-quantification of structural attributes (i.e. lignin) important for the decomposition. Thus, the results show that the intra and interspecific interaction between floral and leaf litter is an important pathway for the priming effect, further increasing the ecological relevance and universality of the phenomenon.

8
  • THAYNÁ LARISSA DA SILVA RABÊLO COSTA
  • PRIORITY AREAS FOR RESTORATION OF ECOSYSTEM SERVICES IN CAATINGA BIOME

  • Advisor : ADRIANA ROSA CARVALHO
  • COMMITTEE MEMBERS :
  • ADRIANA MONTEIRO DE ALMEIDA
  • ADRIANA ROSA CARVALHO
  • EURICO MESQUITA NOLETO FILHO
  • Data: Feb 28, 2020


  • Show Abstract
  • In the Brazilian semiarid, the Caatinga is susceptible by several chronic disorders that threaten the living conditions of the human population. Ecological restoration is important to achieve biodiversity recovery and ensure the provision of ecosystem services (ES) relevant to the well-being of local communities. However, there is a lack of studies that focus on the mismatches between the ES supply and demand. In this sense, we seek to identify priority areas that address the ES supply and demand. To aim this goal, we use two ES provision (wood and food and / or medicinal use) and an ES regulation (pollination). We developed two scenarios for each service: (i) ES offer which we used the maps of the potential geographic distribution of native tree species and (ii) ES demand, which we included, areas ES supply and demand. We conducted the prioritization in Software Zonation, a responsible spatial tool for prioritizing areas that have the highest potential to increase biodiversity and provide ES. We found a percentage increase in representation in demand scenarios in all SEs, following in increasing order, the provision of food and / or medicinal species (1.5%), provision of wood (1.8%) and the most significant pollination (69.1%). These results indicated that for some ES the supply corresponds to the demand while for others there is a mismatch between them. This ES – provision of food/medicine and wood supply - showed larger overlap between supply and demand, signaling that active restoration actions in these areas can directly contribute to improving the welfare of people dependent on the extraction of forest resources.

9
  • JEAN PATRICK DA SILVA JORGE
  • INDIVIDUAL AND INTERACTIVE EFFECTS OF PREDATION RISK, RESOURCE AVAILABILITY AND HABITAT SIZE ON THE BEHAVOIR OF OVIPOSITION HABITAT SELECTION OF THE MOSQUITO AEDES AEGYPTI (LINNAEUS; CULICIDAE)

  • Advisor : LUCIANA SILVA CARNEIRO
  • COMMITTEE MEMBERS :
  • LUCIANA SILVA CARNEIRO
  • ADRIANO CALIMAN FERREIRA DA SILVA
  • RAFAEL DETTOGNI GUARIENTO
  • Data: Mar 6, 2020


  • Show Abstract
  • ABSTRACT. Oviposition habitat selection is a crucial process for species with complex life cycle, such as the dengue mosquito, Aedes aegypti. The choice of gravid female searching for oviposition site depends on the quality of available habitat. Quality assessment made by the female is based on the physical and chemical habitat caracteristics, wich lately indicate the expected fitness. Based on the assessment of the habitats emanating cues females must respond in order to select the most suitable habitats for survival, growth and development of offspring. Natural selection tends to favor oviposition strategies that maximize parental fitness. In an environment with quality habitats varying in multiple factors, female mosquitoes must perform complex integration of cues and respond to this variation through trade-off. However, there is still little knowledge of how multiple interacting factors affect the assessment of the habitat quality and the females laying eggs response. In order to assess the individual and interactive effects of predation risk, habitat size and resource availability on oviposition habitat selection behavior for Aedes aegypti mosquito, a laboratory experiment with a 2 × 2 × 2 design was carried out. Using artificial containers, the absence or presence of cues from the predator Poecilia vivípara, greater or lesser habitat size (depth) and high or low availability of resources were crossed. Females oviposited more frequently and in greater quantity in habitats considered to be of higher quality (without risk, larger and with high resource). The qualitative decision, denoted by the proportion of oviposited replicas per female, was affected by the risk × resource interaction. Only resource and habitat size had a significant individual effect on this variable. The quantitative decision, denoted by the proportion of the total number of eggs laid per female, was significantly affected by the interactions between risk × resource and resource × habitat size. Again, only resource and habitat size had a significant individual effect. These results confirm that females of Aedes aegypti in search of oviposition sites prefer habitats considered of better quality for oviposit, depositing eggs more frequently and in greater quantity. Such a response proves to be quite complex and seems to be influenced by a trade-off between the predation risk and resource availability and, also, between resource availability and habitat size. This demonstrates that there is an interdependence between the factors that indicate habitat quality in conducting oviposition habitat selection.ion. These findings are relevant for the development of more effective population control strategies for mosquitoes that carry disease and for understanding the patterns of distribution and abundance of species that use temporary aquatic habitats.

10
  • VIRGÍNIA HELEN FIGUEIREDO PAIXÃO
  • Interactions between cacti and vertebrates in a northeastern Brazilian dry forest

  • Advisor : EDUARDO MARTINS VENTICINQUE
  • COMMITTEE MEMBERS :
  • EDUARDO MARTINS VENTICINQUE
  • MAURO PICHORIM
  • VANESSA GABRIELLE NÓBREGA GOMES
  • Data: Mar 17, 2020


  • Show Abstract
  • Cacti species play a major role in frugivory networks in arid and semiarid ecosystems. In such environments, where water and food resources are in short supply most part of the year, cacti stand out for their fruit rich in water and sugar, and its mucilaginous pulp. Several studies reinforced the role of birds, bats, and lizards as effective cacti seed dispersers, although little is known about how these interactions are distributed in a network. Network structure provides information about the system stability in the face of disturbances and how tight or weak are interactions between species. Our objective was to describe network structure of mutualistic network of cacti-seed dispersal by vertebrates in SDTF (Caatinga), Rio Grande do Norte State, Brazil. We also identified the main cacti fruits consumers and their ecological role as seed dispersers. For that, we monitored frugivory in six cacti species using camera-traps during a year. We found 23 vertebrate species feeding on fruits of four cacti species, in a way that these interactions were not nested or modular, which is a common pattern found in mutualistic networks in tropical and temperate regions. Our data show that cacti have a generalist strategy of attracting a wide variety of animals that provide different dispersal services, such as birds, reptiles, and mammals. During our study, we found new interactions between lizards Salvator merianae to P. gounellei fruits and Tropidurus hispidus feeding on T. inamoena flowers. These records were described in a second chapter. For natural regeneration, it is crucial to maintain ecological services provided by functionally diverse of animal seed dispersers and this should be taken in account in conservation actions that aim to restore Caatinga areas dominated by cacti species.

11
  • BRUNO CHARNAUX LONZETTI
  • Can ocean warming help zoanthids outcompete branching hydrocorals?

  • Advisor : GUILHERME ORTIGARA LONGO
  • COMMITTEE MEMBERS :
  • BÁRBARA SEGAL RAMOS
  • GUILHERME ORTIGARA LONGO
  • IGOR CRISTINO SILVA CRUZ
  • Data: Mar 31, 2020


  • Show Abstract
  • Given the spatial limitation in reefs, competitive interactions among sessile organisms often occur through physical contact, such as coral-seaweed competition. Ocean warming and acidification may affect the outcomes of these interactions, by changing the competitive ability and recovery potential of the interacting organisms. In the Southwestern Atlantic, one of the most important competitors to corals is the zoanthid Palythoa caribaeorum, which under warming scenarios may expand its distribution and likely dominate reefs, particularly in Northeast Brazil. If this occurs, it would likely outcompete the hydrocoral Millepora alcicornis, one of the most important species that adds structural complexity to Brazilian reefs. We studied the competitive interaction between the zoanthid (P. caribaeorum) and the hydrocoral (M. alcicornis) through field and laboratory experiments, particularly addressing: the effect of physical contact on the hydrocoral´s health (field and laboratory); the recovery potential of hydrocorals, once the contact is ceased (field and laboratory); and how ocean warming potentially affect these processes (laboratory only; 27°C vs. 30°C predicted for 2100). Additionally, as the competitive interaction may be potentially mediated by chemical compounds of the zoanthid, we extracted surface compounds and tested their effects on the hydrocoral in the field and in the laboratory under different temperature scenarios. We found that contact with the zoanthid caused more damage than with the mimetic control in the field and under 27°C after 24h of contact in the lab. Hydrocorals in the field did not recover over a short time span (10 days), but in the laboratory they partially recovered the damaged area in the same period, when under current temperatures (27°C). When under future temperatures (30°C), filamentous algae colonized the area of hydrocorals previously contacted by the zoanthid. Although hydrocorals presented similar symptoms when comparing the current and future temperature scenarios, the recovery potential decreased with warming as it favored colonization by filamentous algae. The greater damage observed in the field and on the first day at lab’s 27°C were signs of P. caribaeorum’s chemical activity favoring competition, which were confirmed with the chemical tests. Those tests indicated a chemical influence on the interaction and revealed that a 3°C raise in temperature makes any contact a damaging one. As ocean warms, the competitive interaction we studied will become more frequent and zoanthids more likely to overgrow the branching hydrocorals, and possibly other branching corals in areas where zoanthids are abundant, as in the Caribbean reefs, causing reef flattening and potentially loss of diversity. This highlights the importance of understanding how ecological interactions will be affected by global changes, as it allows us to predict future dominance scenarios.

12
  • GABRIEL HENRIQUE SANTOS SILVA
  • Importance of abiotic and biotic predictors of the plant community on litter decomposition in a seasonal tropical forest: A long-term approach via mass balance

  • Advisor : ADRIANO CALIMAN FERREIRA DA SILVA
  • COMMITTEE MEMBERS :
  • ADRIANO CALIMAN FERREIRA DA SILVA
  • GISLENE MARIA DA SILVA GANADE
  • ALAN MOSELE TONIN
  • Data: Jun 22, 2020


  • Show Abstract
  • Vegetal detritus decomposition is a key process in nutrient cycling and can be affected by both biotic and abiotic factors. Although many studies have evaluated the effects of litter diversity on its decomposition rate, most works use experimental and short-term approaches. Our aim were, using an observational approach based on estimates of the mass balance between the input and the debris stock during 3 years. For that, we assess, in 41 plots in a restinga forest fragment, the litterfall, soil litter, taxonomic, functional and phylogenetic litter diversity, C:P and C:K ratios and water-holding capacity of litter, in addition to the soil moisture and N, P and K concentrations. After building 54 models of path analysis, our significant models showed that soil moisture was the only variable to affect the decomposition rate of litter in our communities. The results suggest that the decomposition of the litter is not driven by any of the possible effects of diversity: neither by mechanisms of selection nor of complementarity. In fact, at our study site, the results indicate that the decomposition of plant debris is affected by physical attributes of the environment, i.e. soil moisture, probably because it affects the activity of the decomposing microorganisms.

13
  • ELLEN CRISTINA MÕES OLIVEIRA
  • PATTERNS OF HABITAT USE OF TATUS IN BRAZILIAN CENTRAL AMAZON FLOOD PLAINS

  • Advisor : EDUARDO MARTINS VENTICINQUE
  • COMMITTEE MEMBERS :
  • MAÍRA BENCHIMOL DE SOUZA
  • EDUARDO MARTINS VENTICINQUE
  • GUILHERME SANTOS TOLEDO DE LIMA
  • Data: Jul 27, 2020


  • Show Abstract
  • The distribution of mammals in the environment is modulated by habitat complexity and changes in resource availability. They respond to landscape components which direct how they will use the habitat. Far from being a homogeneous forest, the Amazon is formed by different types of vegetation due to the flood pulse that occurs throughout the hydrological cycle. This phenomenon dictates habitat use patterns for many species and explains the great diversity of mammals found in the biome. Tatus (Dasypodidae: Cingulata) are the main group of excavating mammals of the Amazon rainforests. In this study, our objective was to identify which areas tatus are occupying related to the hydrological cycle and which environmental characteristics are influencing the patterns in habitat use. Data were collected from the Piagaçu-Purus Sustainable Development Reserve and Abufari Biological Reserve, located in the central-western portion of the Brazilian Amazon through photographic trapping. 72 cameras were installed in non-flooded areas (solid ground), adjacent to wetlands (floodplains), with a total sampling effort of 23080 days, where three tatus species were detected.From this, we used occupation models, taking imperfect detection into account, to estimate the detection and occupation for each species between the phases of the hydrological cycle (flood and drought), and the influence of environmental variables (relief roughness, Altitude in relation to river level, Predator Density, Wetland boundary distance and Forest Biomass) and anthropogenic (Distance from human communities) at each sampling point. We obtained 700 records independently of the three tatus species. The main results of the occupation models was that Dasypus Novemcinctus and Priodontes Maximus showed a higher occupancy in the solid ground areas during the drought when flooded areas became available (Ѱ = 0.69 ± 0.02 and Ѱ = 0.95 ± 0.12 ), than during the Flood (When flooded areas are full, therefore unavailable for terrestrial species to occupy). For Dasypus Kappleri, the occupation was higher during the Flood phase of the river (Ѱ = 0.98 ± 0.10). Relief roughness and altitude in relation to the river level were the most important variables for Dasypus Novemcinctus occupation when the weight of all models was added. For Priodontes Maximus the distance from the limit of the flooded area was more important for its occupation. For Dasypus Kappleri, the most important variables were the distance from the human community and the roughness of the relief.

14
  • MARIA IOHARA QUIRINO AMADOR
  • Memory of active stakeholders can be used to identify recent and historical changes in reef environments

  • Advisor : PRISCILA FABIANA MACEDO LOPES
  • COMMITTEE MEMBERS :
  • VINICIUS JOSÉ GIGLIO FERNANDES
  • MARIANA BENDER GOMES
  • PRISCILA FABIANA MACEDO LOPES
  • Data: Jul 29, 2020


  • Show Abstract
  • Reefs are sensitive ecosystems affected by global changes (e.g., warming and acidification of the oceans) and local impacts (e.g., fishing and eutrophication). Recent records show that these ecosystems are changing rapidly, although the magnitude and timing of these changes are still unclear. We assessed changes in the seascape of Brazilian reefs, interviewing key stakeholders that make different uses of these ecosystems, such as fishermen, divers, and researchers. For most stakeholders, the health of Brazilian reef environments has been declining since the 1970s, evidenced by the decline of herbivorous fish within the Labridae: Scarinae (parrotfish) group and reef builders (massive corals). On the other hand, these authors also detected an increase in algae and smaller fish of the family Pomacentridae (damselfishes), in addition to pointing out the recovery of sea turtle populations. Assessing the memory of reef users allows determining the timing of these changes, to identify regional idiosyncrasies and groups of organisms that are most vulnerable to changes. This information is important to inform protection and conservation efforts, especially in developing countries, where marine research is relatively new or insufficient.

15
  • PAULO IVO SILVA DE MEDEIROS
  • Effects of water level reduction on the dynamics of zooplankton and their predators in two shallow lakes semi-arid tropical

  • Advisor : JOSE LUIZ DE ATTAYDE
  • COMMITTEE MEMBERS :
  • JOSE LUIZ DE ATTAYDE
  • ADRIANO CALIMAN FERREIRA DA SILVA
  • ROSEMBERG FERNANDES DE MENEZES
  • Data: Aug 7, 2020


  • Show Abstract
  • The reduction in the volume of lakes and reservoirs due to the increase in water deficit during periods of drought, should affect the structure and trophic dynamics of these ecosystems, increasing the concentration of organisms, the rates of encounter between predators and prey and, consequently, pressure of predation. The objective of this work was to investigate the effects of water level reduction caused by extreme drought events on the densities of zooplanktonic organisms and their predators in two reservoirs in the Brazilian semi-arid tropical region. The tested hypothesis is that the densities of zooplankton predators increase with the reduction of the volume of water caused by drought, favoring zooplankton prey less vulnerable to predation over the most vulnerable. To test this hypothesis, the densities of zooplanktonic organisms (rotifers, cladocerans and copepods) and their main predators (fish larvae and juveniles, shrimp larvae, hydracarina mite and chaoboridae larvae) were monitored for 24 months in two shallow artificial lakes of the Brazilian semi-arid region during a drought period (2012-2014). In one of the lakes, about 5.8 tons of adult fish were to remove to prevent massive fish mortality when the volume of water and oxygen reached a critical level. Zooplanktonic organisms were collected monthly by means of vertical trawls with a plankton net with a 68 µm opening and their predators were collected monthly by means of horizontal trawls with an ichthyoplankton mesh with a 500 µm mesh opening and a flow meter to measure the filtered volume. The organism densities were to analyze over the study period and Spearman correlations were to perform to evaluate the possible interactions between zooplanktonic organisms and their predators and the effects of reduced water volume on the studied organisms. In both lakes, rotifers dominated zooplankton and chaoboridae larvae were the most abundant predators. In the lake where there was no removal of adult fish, the densities of fish larvae to increase, the densities of chaoboridae larvae decreased and those of copepods increased with the reduction of the water level. On the other hand, in the lake where adult fish were remove, the densities of fish larvae, shrimp and rotifers decreased while the densities of chaoboridae larvae increased with the reduction of the water level. These results indicate that the water level reduction caused by drought tends to vary the abundance of predators, changing the relative importance of predation by vertebrates and invertebrates and causing changes in the structure of zooplankton communities depending on local conditions.

Thesis
1
  • LUDMILA DE MELO ALVES DAMASIO
  • USE OF ECOLOGICAL AND SOCIOECONOMIC INDICATORS TO ASSESS CHANGES IN FISHERIES

  • Advisor : PRISCILA FABIANA MACEDO LOPES
  • COMMITTEE MEMBERS :
  • PRISCILA FABIANA MACEDO LOPES
  • JOSE LUIZ DE ATTAYDE
  • CARLOS SEBASTIAN VILLASANTE LARRAMENDI
  • JOÃO VITOR CAMPOS E SILVA
  • RODRIGO SILVA DA COSTA
  • Data: Jan 22, 2020


  • Show Abstract
  • Providing fish and seafood from fishery catches is one of the most important ecosystem services that humans derive from the ocean, and as such, commercial fisheries regulation should be a priority. In order for the assessment of multi-specific fisheries to be broader and more sensitive to change, it is advisable to investigate various types of indicators, portraying the broadest possible scenario. Using reconstruct landing data and data provided by fishermen, this project proposes, through the Marine Trophic Index, Species Distribution Models and socioeconomic indicators to evaluate changes in fishing in the Brazilian equatorial region and how these changes impact fishermen, using communities from Rio Grande do Norte and Ceará as case studies. The results are expected to help better understand the changes and dynamics of fisheries and fish stocks in this region, helping to subsidize fisheries management decisions

2
  • MARINA VERGARA FAGUNDES
  • FUNCTIONAL TRAITS OF CAATINGA SEASONALLY DRY TROPICAL FOREST: FUNCTIONAL STRATEGIES, SPATIAL DISTRIBUTION, PLANT INTERACTIONS AND RESTORATION PRACTICES.

  • Advisor : GISLENE MARIA DA SILVA GANADE
  • COMMITTEE MEMBERS :
  • LUCY ROWLAND
  • FLÁVIA REGINA CAPELLOTTO COSTA
  • GISLENE MARIA DA SILVA GANADE
  • INARA ROBERTA LEAL
  • VANESSA GRAZIELE STAGGEMEIER
  • Data: Feb 13, 2020


  • Show Abstract
  • Functional traits are all physiological, morphological anatomical and biochemical features of an organism that allow it to survive and reproduce in its environment. The functional traits of organisms, here limited to tree species, in a given region, are primary selected by environmental filters. The understanding of how the environment modulates vegetation community is a worldwide question in Ecology. Once limited by environmental conditions, the functional traits will also exert effects on its environment, by changing abiotic resources and condition, affecting the surrounding organisms. Such effect can also modulate community structures. Understand both processes its fundamental to the understanding not only general ecological patterns, but to generate information in order to apply ecological theories to rebuild communities as in restoration programs. Mentioned that, this work is made by 3 independent chapters all focused in Seasonal dry Forest Caatinga. The first chapter aim to analyzed tree species coordinated trade-offs of one of the most biodiverse Seasonal tropical dry forest, determined its functional groups gathering above-below ground and biochemical traits, test if these groups are spatially associated over the biome and if the distribution is limited to a aridity gradient. We sampled several anatomical, physiological, structural and biochemical functional traits of 20 adult tree species in situ, and young plants of 2 and 6 months old cultivated in a greenhouse. We performed PCA test, K-means. Ripleys K analysys and gls to respond the aforesaid questions, respectively. We found distinct coordinated trade-offs representing the slow-fast growth strategies continuum. This continuum were collapsed in two main groups of acquisitive and conservative strategies, and the majority of species were selected to conservative group. Species of both groups are independently distributed over the biome, and fast-strategy species occurrence is more related to arid regions than slow-strategies. The second chapter aim to test which functional traits are important to explain facilitation capabilities of nurse plants, and if specific combinations of nurse-target functional traits explain the outcome of species-specific interaction. We performed a in-situ experiment with 60 adult plant-target tree species combination replicated 5 times. Using the already sampled functional traits as predictive variable and plant neighbour performance as response variable, we performed a GLMM followed by variable simplification. We found that both conservative and acquisitive species can exert positive effects and the outcome is highly dependent on the pair of species match. The positive outcome however, happened when the species exerting the effect, had functional traits which effect on environment, fulfill the ecological above- or below-ground requirements of its plants neighbour. At least, the third chapter, aim to disentangle the facilitation from functional complementarity effects, and test the importance of this components on biomass production and community function. We produced 4704 seedlings of 16 semiarid tree species using a new growing method. All individuals were planted in 147 experimental build communities of 13 m X 18 m, with 32 individuals each. The experimental communities were build at five levels of diversity and with distinct composition at each level replicated three times. The biomass production and the Net biodiversity Effect (NBE) were calculated and used as response variables. As a predictive variables we used facilitation community potential, community weighted mean and functional diversity based on above and below-ground traits. For both response variables, we performed a generalized linear mixed models to understand how they drive the productivity and function of communities. We showed that facilitation is a key process for restoration acting since the community biomass productivity until its net biodiversity effects. Both parts of complementarity effect, functional diversity and facilitation, are fundamental for a higher community function at the initial years of rebuilt communities.Additionally, we showed how to manipulate the three components of the Net biodiversity Effect, facilitation, functional diversity and community functional identity, in order to guide future restoration programs.

3
  • REGINA LÚCIA GUIMARÃES NOBRE
  •  

    EVALUATING THE INFLUENCE OF LAND USE, LANDSCAPE PROPERTIES, PRECIPITATION AND FISH ON AQUATIC ECOSYSTEM FUNCTIONING AND BIODIVERSITY THROUGH LARGE TEMPORAL AND SPATIAL SCALE ASSESSMENTS ACROSS LAKES AND RESERVOIRS     

  • Advisor : LUCIANA SILVA CARNEIRO
  • COMMITTEE MEMBERS :
  • JULIANA DEO DIAS
  • LUCIANA SILVA CARNEIRO
  • RAFAEL DETTOGNI GUARIENTO
  • ROSEMBERG FERNANDES DE MENEZES
  • VANESSA BECKER
  • Data: Feb 14, 2020


  • Show Abstract
  • Nutrient cycling is a fundamental ecosystem service as it provides an adequate balance of elements that are necessary for life. In freshwaters, the balance of nitrogen (N) and phosphorus (P) are of special interest as they often limit or control primary production and biomass formation. While the availability of these nutrients is fundamental for the maintenance of biodiversity and productivity of freshwaters, their excess can lead to eutrophic conditions that are associated with impaired water quality and biodiversity loss. The nutrient balance in freshwaters can potentially be affected by a variety of biotic and abiotic, external and internal pathways. In this thesis, two frameworks were explored. First, a spatial framework focused on external processes, where we investigated the direct and indirect effects that land use (i.e. type, extent), precipitation and landscape properties (i.e. lake origin, lake and catchment absolute and relative size and geomorphology) have on biotic and abiotic properties of freshwater systems. More specifically, in chapter one we evaluated, across 98 tropical lakes and reservoirs, the individual and interactive effects of land use, precipitation and landscape properties on patterns of water quality parameters (N, P and chlorophyll-a). In chapter two, we characterized the 98 lakes as natural or artificial and compared them regarding the landscape properties of their surroundings, their morphometry, and their physico/chemical characteristics to verify whether those factors can be associated with average patterns of phytoplankton community structure at both local and regional scales. The second approach, presented in Chapter 3, was a long-term temporal framework focused on internal processes related to nutrient cycling where we assessed whether an omnivorous fish with high biomass and growth rate is a source or sink of N and P to the pelagic zone of a temperate eutrophic lake, at various time scales ranging from days to 20 years. 


4
  • ELIZIANE GARCIA DE OLIVEIRA
  • Soundscapes and the use of acoustic monitoring in Brazilian biomes

  • Advisor : RENATA SANTORO DE SOUSA LIMA
  • COMMITTEE MEMBERS :
  • FLÁVIO HENRIQUE GUIMARÃES RODRIGUES
  • GILBERTO CORSO
  • GUILHERME SANTOS TOLEDO DE LIMA
  • JULIO ERNESTO BAUMGARTEN
  • RENATA SANTORO DE SOUSA LIMA
  • Data: Feb 28, 2020


  • Show Abstract
  • Soundscape studies has becoming more popular nowadays as an important tool with the potential to evaluate environmental health, changes in land use, climate change, in several temporal and spatial scales. In tropical environments, the high biodiversity associated with a restricted taxonomic knowledge for many taxa and the lack of financial resources make the acoustic ecology studies more challenging than in other regions. At the same time, tropical areas are the most important in terms of biodiversity conservation, and the use of acoustic monitoring is even more relevant once it can facilitate long-term studies at a lower cost than traditional ecological surveys. Facing a reality of rapid technological innovations and data analysis methods in the acoustic ecology field, this thesis has the main goal of evaluate the use of passive acoustic monitoring in Brazilian biomes, providing analysis protocols and contributing to advance of acoustic ecology in tropical regions. The thesis is divided in three chapters and an appendix with other production non-related to the thesis. In the first chapter we describe patterns in use of acoustic space in a Caatinga area by clustering multiple acoustic indices. During dry season, wind was predominant in the recordings, while in rainy season, was biophony. Daily variations included the birds and wind occupying the acoustic space during the day, while insects predominated at night. In the second chapter, also in a Caatinga area, we aimed to understand how a windfarm facility modifies the soundscape around it. We’ve found that biophonic activity increases as we move closer to the turbines, suggesting that both birds and insects have their acoustic activity patterns modified in response to wind turbines presence. In the third chapter, we used data from Caatinga, Cerrado and Atlantic Forest, to teste whether single indices are able to predict bird species richness and if a composition of several indices allow discrimination of different species’ composition. We’ve found that single indices performance is variable among habitats, and features of birds’ communities as predominance of species and frequency bands used may be affecting the indices results. Even so, a combination of indices was able to distinguish among biomes.

5
  • EUGENIA DE JESUS CORDERO SCHMIDT
  • Interactions, Persistence and Coexistence Mechanisms of Nectarivorous Bats and the Plants they Feed on, in a Seasonally Dry Tropical Forest in Northeastern Brazil

  • Advisor : EDUARDO MARTINS VENTICINQUE
  • COMMITTEE MEMBERS :
  • VALERIA DA CUNHA TAVARES
  • PATRICIO ADRIANO DA ROCHA
  • EDUARDO MARTINS VENTICINQUE
  • ERICH ARNOLD FISCHER
  • VANESSA GRAZIELE STAGGEMEIER
  • Data: Mar 2, 2020


  • Show Abstract
  • Seasonal Dry Tropical Forests (SDTF), such as the Caatinga, are considered adverse environments due to their high temperature, scarce and variable rainfall and seasonal restrictions on the availability of water and food resources. These characteristics can affect the assemblies of mammals and plants and, therefore, their life histories. Several mechanisms of persistence in neotropical SDTFs have been described for bats (migration, dietary plasticity, morphological differences, foraging strategies) and for plants (deciduity, spines, seasonal phenology), all influenced by precipitation and temperature. In this doctorate we delve into the lives of four species of nectar-feeding bats: Glossophaga soricina (Phyllostomidae: Glossophaginae), Lonchophylla inexpectata, Lonchophylla mordax and Xeronycteris vieirai (Phyllostomidae: Lonchophyllinae). We describe their interaction networks with plants (Chapter 1), explore their mechanisms of persistence and coexistence over time (Chapter 2) and, finally, tested the influence of precipitation and the availability of Cactaceae resources on the reproduction patterns of the nectar-feeding bats (Chapter 3). The field work was carried out in seven locations in the state of Rio Grande do Norte, between May 2015 and February 2019. Using mist nets to capture the bats, we noted the capture hour, species, reproductive status, sex and eco-morphological measures. To characterize the species' diet, we collected bat hair pollen samples (glycerin gelatin cubes) and fecal samples. To determine the availability of resources, we collected phenological flowering data of nine plant species.

    The studied nectarivorous bats interacted with 31 plant species forming a network with a highly generalized pattern of interactions, consistent over the seasons and years. The observed generalization may be a necessary condition for the persistence of nectarivorous bats and their specialized plants in variable and challenging environments such as the Caatinga. In chapter two, we were able to prove that the four species of nectarivores coexist and persist over time (years and seasons) mediated by a mixture of mechanisms (temporal partitioning, eco-morphological differences and resource partitioning). Finally in chapter three, we found that precipitation positively affected the probability of ocurrence of pregnancy in L. mordax and X. vieirai. None of the tested variables (precipitation nor Cactaceae resources availability) influence the pregnancy of G. soricina. On the other hand, the availability of floral resources of Cactaceae from the previous month, positively affected the probability of occurrence of lactation for all nectarivorous bats. With this research, we were able to emphasize the importance of interactions between cacti and bats. The Cactaceae family is a key resource for the persistence, coexistence and reproduction of nectarivorous bats in the Caatinga, therefore conservation initiatives should consider areas with high abundance and diversity of Cactaceae as a priority.

6
  • JUAN CARLOS VARGAS MENA
  • The spatial and temporal structure of bat (Chiroptera) assemblages in Caatinga dry forests in northeastern Brazil

  • Advisor : EDUARDO MARTINS VENTICINQUE
  • COMMITTEE MEMBERS :
  • MARLON ZORTÉA
  • EDUARDO MARTINS VENTICINQUE
  • ENRICO BERNARD
  • MAURO PICHORIM
  • VALERIA DA CUNHA TAVARES
  • Data: Mar 5, 2020


  • Show Abstract
  • Seasonal Dry Tropical Forests (SDTF), such as the Caatinga, are considered adverse In the Caatinga dry forest, key factors that controls the structure and dynamics of the bat assemblages have been attributed to the spatial heterogeneity of different ecoregions and phytofisiognomies,and to seasonality of rain and pulses of food resource. Almost 95% of Rio Grande do Norte (RN) state correspond to Caatinga where it harbors abundant subterranean cavities (~1000 caves). Because patterns of spatial and temporal diversity of the bat fauna are virtually unknown in the Caatinga, the main objective of this thesis was to explore the spatial and temporal patterns of richness and species composition of bat assemblages in different landscapes, phytofisiognomies and cave roosts. In Chapter 1, I explored the richness and spatial and temporal diversity in trophic and species composition of bat assemblages through mist-net captures in 5 different Caatinga habitats in six regions throughout RN. In 100 sampling nights, I captured 1575 individuals of 31 species with a net capture effort of 239 824 m2h. Differences in the structure was found at the species- and ensemble-level (trophic guilds) between the assemblages both in the different studied areas and in the different habitats. This is likely related to species specific preferences to favor specific landscape characteristics and foraging habitats. Richness and species composition presented no evident seasonal variation between season. Food resource found along the year may be the key factor that sustain a similar structure of the bat assemblage year-round. In Chapter 2, I monitored nine caves in four regions in RN to examine the effects of the seasons and cave size on the richness and species composition at a roost level. Using two methods we recorded 17 bat species of 2045 captured and 4181 observed individuals in 61 sampling days. Richness and species composition did not change seasonally and no temporal turnover of species was found as well. Yet, increase in overall bat abundance and for some species (insectivores and piscivores) was found mostly in the rainy season. High bat abundance in the rainy season did not coincided with precipitation peaks but an evident abundance decrease coincided with the driest months. A synergy between seasons and cave size was found where in the rainy season large caves tended to vary more in abundance than small caves. As well, differences in species composition was found between large and small caves. Seasonally abundance increase is likely attributed to reproductive purposes. Most of the species were reproductively active during the rainy season where their preferred food was more abundant (frugivores, insectivores and animalivores), while others that rely on year-round available food resources were active during both season (sanguinivores, omnivores and unexpectedly nectarivores). In Chapter 3, I did a taxonomic revision in collections and bibliographic review to determine the gamma diversity of RN and present the first official list of bats of the state, including new records and discussion on conservation and priority research areas. Overall, the data obtained from 44 bat species of 3630 captured individuals and more than 4000 observed bats in 161 sampling days indicates that in general, bat assemblages are adapted to stay year-round in the studied areas but are strongly affected by spatial and by the vegetational structure of their preferred foraging areas. While inside roosts, temporal factors such as food availability strongly affect the reproduction activity of bat assemblages and reinforces the importance of caves of all sizes for the reproduction and protection of Caatingas’ bat populations, including of endemic and vulnerable species. The effort of this thesis, with the key collaboration of many valuable people, is a way to describe and have a deeper insight into the natural history and ecology of the poorly known bat fauna of the seasonal Caatinga dry forest in Brazil

7
  • PAULO HENRIQUE DANTAS MARINHO
  • Occurrence and coexistence’s patterns of medium to large-sized mammals in Caatinga

  • Advisor : EDUARDO MARTINS VENTICINQUE
  • COMMITTEE MEMBERS :
  • EDUARDO MARTINS VENTICINQUE
  • MAURO PICHORIM
  • CLAUDIA BUENO DE CAMPOS
  • FABIANA LOPES ROCHA
  • RODRIGO LIMA MASSARA
  • Data: Apr 28, 2020


  • Show Abstract
  • Dry tropical forests are threatened and little-known ecosystems where the association between the semiarid climate and the generally high environmental degradation imposes challenges for the persistence of wild fauna. In this context, medium to large-sized mammals (MLSM) are especially affected by anthropogenic disturbances, among which, carnivores are intensely persecuted, impairing their role in structuring biological communities through predation and intraguild competition. In this thesis, we investigated the occurrence and coexistence patterns of MLSM in different landscapes of the Caatinga, the Brazilian dry tropical forest, using camera trapping data. Specifically, we 1) carried out the first systematic survey of MLSM in the Rio Grande do Norte state (RN), sampling 10 priority areas for conservation; 2) we described the daily and seasonal activity patterns and estimated the temporal overlap among mesocarnivores using circular statistics and non-parametric analyzes of activity overlap; 3) we investigated the patterns of spatial co-occurrence between a dominant mesopredator (Leopardus pardalis) and sympatric mesocarnivores, considering seasonality and using conditional co-occurrence models; and finally, 4) we tested the relative effects of environmental and anthropogenic predictors on MLSM’s occupancy in a landscape disturbed by high cattle density and during a period of extreme drought, using Bayesian occupancy models in a multi-species approach. As main results, we found 1) a wealth of 14 MLSM’s species in the Caatinga of RN, which represents 50% of the MLSM registered at north of the São Francisco River, including threatened species as a top predator (Puma concolor). 2) Mesocarnivores were mainly nocturnal throughout the dry and rainy seasons, overlapping most of their daily activity, but segregating the peaks of greater activity, which may represent a coexistence mechanism. Meanwhile, Herpailurus yagouaroundi was diurnal, avoiding encounters with competitors and synchronizing its activity with potential prey. 3) Spatially, the other mesocarnivores used the habitat regardless L. pardalis’ presence, with the exception again of H. yagouaroundi, which seems to prefer the same locations as this dominant mesopredator, probably because they have better conditions and resources, while temporal segregation decreases risk of aggressive encounters. 4) MLSM occurred mainly in patches of forest vegetation, which represent a key habitat for the persistence of this group in a degraded landscape under prolonged drought, and where many species showed an extremely low abundance. Therefore, these environments must be protected to guarantee MLSM’s persistence in Caatinga. Our results reinforce the relevance of priority areas and habitats for mammals’ conservation in the Brazilian dry tropical forest, in addition to elucidating the intraguild coexistence strategies that maintain the mesocarnivores diversity in this semiarid environment.

8
  • CAROLINA TEIXEIRA PUPPIN GONÇALVES
  • MACROALGAE BLOOMS AND THEIR EFFECTS ON FISHERY AND MACROFAUNA IN A NEOTROPICAL REGION

  • Advisor : FULVIO AURELIO DE MORAIS FREIRE
  • COMMITTEE MEMBERS :
  • CARLOS EDUARDO ROCHA DUARTE ALENCAR
  • ELIANE MARINHO SORIANO
  • FULVIO AURELIO DE MORAIS FREIRE
  • TIEGO LUIZ DE ARAÚJO COSTA
  • VINICIUS PERUZZI DE OLIVEIRA
  • Data: Jun 30, 2020


  • Show Abstract
  • Macroalgae play important ecosystem functions in aquatic ecosystems: they contribute to primary production and nutrient cycling, generate complex environments, act as shelter and provide food and nesting surfaces for many species. However, environmental changes related to anthropic activities have been causing the eutrophication of aquatic ecosystems due high nutrient inputs in the water bodies. Eutrophic environments favor the massive algae proliferation, commonly known as blooms. Blooms can cause drastic impacts on ecosystems by oxygen depletion and toxins releases, consequently generating social and economic issues. In this thesis, we aim to verify the impacts caused by macroalgae blooms encompassing the environmental, social, and economic effects. In the first chapter, we evaluate the Ulva lactuca blooms in a hypersaline estuary on the semiarid coast. We analyzed macroalgae abundance in relation to physical-chemical factors during dry and rainy seasons. Our results support greater abundance during dry season, mainly concentrated in the upstream region of the estuary. During dry seasons, the river exhibits slower currents and less turbid waters while nutrients are accumulated, providing the ideal scenario for U. lactuca development. In the second chapter, we intend to provide possibilities for macroalgae biomass uses. As a bioaccumulator species, we also verified the metal concentration on its tissues. Macroalgae exhibited high levels of metal concentration, limiting its use for biomanipulation, biofuels and biofilters agents. In the third chapter, we aimed to better understand the impacts of U. lactuca blooms on fishery using the local ecological knowledge provided by fishermen. Fishermen information’s indicated that blooms mainly occur during the dry period in the estuarine region. Net gears were heavily impacted by macroalgae blooms and fishes were the mainly impacted resource. Finally, in the fourth chapter, we evaluate the impacts of macroalgae on comercial shrimps and other benthic macroinvertebrates of bottom trawling fishery in two distinct climatic zones: tropical zone and dry zone. The dry zone showed greater algae biomass than in tropical zone. On the other hand, shrimp productivity was higher in the tropical zone. Shrimp diversity indexes were negatively related to algae richness, indicating that algal banks are usually avoided by the species. The benthic macrofauna density, on the other hand, exhibited a positive relationship with macroalgae biomass. However, when evaluating the relations for each species, the influences were positive and negative dependending on the species diet and preferential habitat.

9
  • ANDRESSA BÁRBARA SCABIN
  • Cascading effects of hunting on vertebrates and plant communities in Amazonian forest landscapes 

  • Advisor : CARLOS AUGUSTO DA SILVA PERES
  • COMMITTEE MEMBERS :
  • ALEXANDRE FADIGAS DE SOUZA
  • CARINE EMER
  • JOÃO VITOR CAMPOS E SILVA
  • MAÍRA BENCHIMOL DE SOUZA
  • RICARDO SIQUEIRA BOVENDORP
  • Data: Jul 30, 2020


  • Show Abstract
  • Overhunting is one of the greatest threats to wildlife worldwide and has caused a sharp decline in the abundance of large-bodied vertebrate populations in tropical forests. The implications are far-reaching since the most intensely hunted species are often involved in key ecological processes related to forest dynamics, including seed dispersal and predation. Defaunation disrupts these plant-animal interactions, which are essential for forest regeneration, and can compromise the maintenance of plant diversity and ecosystem services. This thesis explores the cascading effects of defaunation on vertebrate and plant communities using a hunting pressure gradient in the Médio Juruá region of western Brazilian Amazonia. In the first chapter, we analysed the direct and indirect effects of hunting on mammal and bird communities. For this, we estimated vertebrate biomass using camera trapping in both the understory and forest canopy at 30 sites distributed along the hunting gradient. Overhunted forests showed changes in the size structure of the animal community with a decline in the biomass of hunting-sensitive species and an increase in the abundance of nocturnal rodents, possibly related to a density compensation mechanism. The second chapter explores the cascading effects of defaunation on future forest composition and functionality. We compared functional traits of trees and saplings, inventoried in 30 plots of 0.25 ha (=7.5 ha) established along the hunting gradient, to test for an expected decrease in traits associated to seed dispersal by large vertebrates. Our results indicated a modest decrease in the abundance of large vertebrate dispersed saplings compared to conspecific trees, and an increase in the prevalence of saplings from abiotically dispersed species. However, this effect did not reflect the community-wide pattern for the continuous traits of wood density, leaf mass/area (LMA) and seed mas. In the third chapter, we used dendrometric data from our forest inventory and comprehensive wood density sampling to estimate current and future carbon stocks, and thereby assess the potential impact on carbon stocks in intensively hunted forests. Of the 30 plots sampled, 22 could lose forest carbon in the future and the mean projected loss was 2.2 MgC ha-¹. For two protected areas (PAs) in the study landscape, the projected loss was approximately 1,560 MgC. Considering the currently predicted monetary values in the international carbon market, the projected decrease in the PAs future carbon stock was valued at US$15,600 to US$120,000.

10
  • NADIA SELENE ZAMBONI
  • VALUATION OF COASTAL ECOSYSTEM SERVICES IN CLIMATE CHANGE SCENARIOS

  • Advisor : ADRIANA ROSA CARVALHO
  • COMMITTEE MEMBERS :
  • ADRIANA ROSA CARVALHO
  • FULVIO AURELIO DE MORAIS FREIRE
  • EURICO MESQUITA NOLETO FILHO
  • CARLOS HENRIQUE FIGUEIREDO LACERDA
  • JORGE LUIZ RODRIGUES FILHO
  • Data: Jul 30, 2020


  • Show Abstract
  • The current scenario of climate change and population growth in coastal areas has led to loss of habitat and ecosystem services (ES) for coastal populations. Currently, there is little understanding about the effect of these drivers on the distribution and value of ES in coastal environments over time. In order to understand the dynamics of loss in the supplying of coastal ES and their corresponding loss in economic values, in this thesis we proposed to address these issues over three chapters. The main objectives were (1) to map the bias of the most valued coastal environments and ecosystem services in the world, as well as the distribution of economic benefits generated by them in relation to some indicators of human and socioeconomic development (CH 1 - Global Distribution and Value of Coastal-Marine Ecosystem Services); (2) to assess the effects of land conversions in a future period of 33 years, on the dynamics of Coastal Blue Carbon services provision by mangroves in Northeast Brazil (CH 2– Effects of Land Use Changes on Blue Carbon Services in Northeast Brazilian Mangrove Areas); and (3) evaluate the vulnerability and the temporal changes in coastal landscape by measuring the erosion/accretion rates in the shoreline and the economic losses and costs from long-term retreats in the coastline and mangroves loss in Northeast Brazil (CAP 3- Coastal Protection Service Delivery in Northeast Brazil in Face of Sea Level Rise). The results obtained in Chapter 1 indicate that a) the most quantified and valued coastal ecosystems worldwide are wetlands and mangroves; b) the most valued ES are recreation, commercial fishing and coastal protection; c) the most widely used valuation methods are willingness to pay and market values; d) The total annual average economic benefits of ES observed worldwide ranged from US$1,100 to US$77 billion; and (e) there is a positive relationship between the ES economic values and the human and socioeconomic development indicators (Gross Domestic Product and Human Development Index). The results obtained in Chapter 2 indicate that the forest area in northeastern Brazil can decrease by almost 35% and the total carbon stored by 22.2% by 2050, driven in large part by the expansion of salt and shrimp farming activities. The total Net Carbon Sequestration (NCS) could reach about 17.3 tCO2e/ha/year, and the Net Present Value (2017) is US $ 2,044.3/ha. Although there are apparently no major variations in the NCS values between periods over 33 years, high values of carbon emissions (1,351.2 tCO2e/ha) could be observed during 2017-2035. The results obtained in Chapter 2 indicate that one third of coastline is under erosion process and the prediction is of losing 630,000 m2 of shoreline until 2026. Mangroves reduce in 20% the moderate-high vulnerability levels of coastal areas from sea-level rise effects, while protecting a fourth part of the total exposed population. Probably this proportion could increase to half the population if total mangrove area were lost, causing costs of more than USD6.1billions (BRL32.4 billions).

11
  • EMERSON SILVA DIAS
  • Biodiversity effects on aquatic ecosystem functioning on multiple trophic levels – an observational study.

  • Advisor : ADRIANO CALIMAN FERREIRA DA SILVA
  • COMMITTEE MEMBERS :
  • ADRIANO CALIMAN FERREIRA DA SILVA
  • CAMILA RODRIGUES CABRAL
  • JOSE LUIZ DE ATTAYDE
  • RAFAEL DETTOGNI GUARIENTO
  • REGINA LÚCIA GUIMARÃES NOBRE
  • Data: Aug 28, 2020


  • Show Abstract
  • Lakes and reservoirs are essential components for human development and carry out important ecosystem processes. Understanding the mechanisms that determine these processes is necessary in a scenario of climate change and consequent increase in the interdependence between society and natural resources. In lentic ecosystems, the production and transfer of matter and energy are largely carried out by the phyto-zooplankton communities. Diversity effects on ecosystem functioning of (BFE), driven by niche partitioning and selection effects in the community can affect these processes positively or negatively. However, it is necessary to elucidate which components of diversity are most important and what is the shape of the relationship between each function and its predictors, in addition to studies that observe these effects in natural environments. Testing the effects of biodiversity in conjunction with abiotic variables over a wide spatial range provides the necessary support to advance knowledge about BFE to predictive and applied models. The aim of this work was to analyze the relationship between different aspects of phytoplankton and zooplankton diversity on the functioning of aquatic ecosystems in 98 lagoons and reservoirs in the state of Rio Grande do Norte, Brazil. To measure functional diversity, metrics were calculated based on the distance of the functional traits of the communities, generating a functional trait space from which the richness, equitability and functional divergence were analyzed. In the first chapter, the effects of the taxonomic and functional diversity of phyto and zooplankton and the intraspecific functional diversity of phytoplankton over biomass and resource use efficiency of nitrogen and phosphorus were assessed. In the second chapter, the relationship between biomass and resource use efficiency of zooplankton and its relationship with the taxonomic and functional diversity of zooplankton and phytoplankton were analyzed. The effects of diversity were analyzed in regressions in Random Forest models, with selection of variables for the measure of importance, analyzing the partial dependence and the magnitude of the effect (ME) between the diversity and the focal ecosystem function. Significant diversity effects of high magnitude of zooplankton functional divergence for zooplankton biomass (ME = 1.09) and negative effects of taxonomic (ME = -0.4) and functional phytoplankton (ME = -0.77) on the rate of resource use of zooplankton. Phytoplankton functional divergence had a strong positive effect (ME = 0.82) on phytoplankton biomass, as well as phytoplankton functional richness (ME = 0.43) and negative effects of phytoplankton functional equitability (ME = -0.56 ). The nitrogen use efficiency of the phytoplankton community was positively affected by its functional divergence (ME = 0.65). The efficiency of phosphorus use has not been shown to be affected by diversity or environmental variables. The inclusion of intraspecific functional richness did not present good predictive abilities for phytoplankton. Dominance effects on ecosystem functions were observed, indicating selection effects of super-dominant cyanobacteria species and strong effects of functional divergence pointing to niche differentiation in highly productive communities at both trophic levels. Non-linear, positive and negative, effects, were observed between diversity and the functioning of ecosystems on a large spatial scale. Observing these effects in real ecosystems in conjunction with environmental variables confirms predictions made in experimental studies and expands the application of BFE in freshwater environments.

12
  • LARISSA NASCIMENTO DOS SANTOS SILVA
  • Ecological patterns and butterfly diversity in dry tropical forests

  • Advisor : MARCIO ZIKAN CARDOSO
  • COMMITTEE MEMBERS :
  • MARCIO ZIKAN CARDOSO
  • MIRIAM PLAZA PINTO
  • MARINA ANTONGIOVANNI DA FONSECA
  • MARILIA BRUZZI LION
  • Solange Maria Kerpel
  • Data: Aug 31, 2020


  • Show Abstract
  • Dry ecosystems are biodiverse and are distributed across the globe, with climatic seasonality being a strong environmental characteristic, which imposes adaptive challenges on the seasons and physiognomic variations on organisms. However, the distribution of dry tropical forests and species has historically been altered by global environmental changes and the intense conversion of habitat into agricultural and logging areas. Currently, the importance of these ecosystems for the maintenance of species is known, including in those areas of the ecotone with humid forests and other biomes. Moreover, studies of taxonomic and ecological comparisons on large scales are scarce, and the patterns of influence of habitat loss are unclear. To investigate how butterfly species are distributed in dry tropical forests and how environmental elements influence communities in fragmented landscapes, the thesis is divided into three main thematic axes: distribution of research effort and wealth patterns, gradient effects impacts on community structure, and the influence of changes in the landscape on species diversity. The objective of chapter 1 was to survey the research effort on butterflies (Papilionoidea and Hesperioidea) to identify the main thematic and geographical research gaps, and to characterize the profile of studies aimed at knowledge and preservation of the biodiversity of these forests. For this, we use scientometric methodology, using keywords in English encompassing dry forests and savannas (Pennington et al. 2018) and the taxon butterflies, on the ISI Web of Knowledge platform. We collected information from 167 screened and mapped studies, published between 1981 and 2019. Most articles are from Brazil (24.6%), Mexico, Malawi and Australia, carried out at different spatial scales and research approaches. Ecological interactions (18.6%) and life history (13.8%) were the main themes, and Nymphalidae (36.5%), the most studied family. We find, mainly in the Americas, inventories, studies of communities and interactions, such as myrmecophilia and host plants associated with Lycaenidae and Pieridae. While several phenological and evolutionary studies have been tested with Satyrinae species in the African region, and seasonal and biogeographic studies in the Australian region, including comparisons with other taxa, such as birds and mammals. Some of the richest areas for butterfly species (Papilionoidea) are in Mexico and Australia. Dry Forests are richer in butterfly species (average 138.2) than Savanas (115.3), corroborating our hypothesis of greater wealth in more heterogeneous and less unstable environments. Considering the less addressed topics, fragmentation (2.4%) and anthropic impacts (1.8%), we warn of the need for research on environmental changes at different scales, as well as the effects of forest fragmentation on biological communities and conservation. In chapter 2, we estimate the effects of habitat structure and the seasonality of resources on the abundance, richness and composition of fruit-feeding butterflies in gradients of productivity and fragmentation, in a dry Brazilian forest. We collected data on the fauna of frugivorous butterflies, in the Seridó region, and on habitat variables in 9 landscapes (6x6 km) of different habitat coverings, during three periods (low, medium and high productivity), between 2017 and 2018. We recorded 16 species and 5,997 individuals, whose greatest abundance occurred in high productivity and in landscapes with high habitat coverage. We identified that communities have their dynamics related to productivity and habitat structure in spatial and temporal gradients. In addition, the butterfly species will respond to changes in the environment according to their functional characteristics, making it possible to observe the most pronounced effects on species-specific characteristics, with alternation of species along the time gradient, mainly. In chapter 3, our objective was to estimate the effects of habitat structure and anthropogenic impacts on the abundance, richness and composition of fruit-feeding butterflies in fragmented landscapes. Our hypotheses are related to theories of niche partition and environmental filters, where the diversity and dynamics of communities are determined mainly by the biota's response to environmental change. In the same 9 landscapes of Seridó, we investigated the elements of the habitat structure and characteristics of anthropic impact, locally and on a landscape scale, using classified images of MapBiomas coverage and land use and local collections. We tested the effects of landscape variables on the wealth and abundance of butterflies and on species composition. We recorded greater wealth and most species had more individuals registered in high and medium forest cover. The species composition differed between the landscapes, as well as the proportion of species of different niche ranges, with a higher proportion of tree forest species (83%) in high coverage landscapes (56-60% of habitat), these species being also those most affected by anthropic changes. We use niche partition tools and identification of bioindicator species to understand the dynamics of communities and rank landscapes in terms of environmental quality. Finally, we present some of these results in products for scientific dissemination, which have been developed with the help of undergraduate students and in partnership with other institutions (UFCG, UFPE, ICMBio and Fund. Boticário): the Seridó Butterfly Guide and the dissemination page for the monitoring project in UCs in Caatinga and Mata Atlântica, @borboletasnonordeste.

2019
Dissertations
1
  • DANIEL ROVIRA PEREIRA TORRES
  • Influence of an incised valley on benthic and fish assemblages on recently described biogenic reefs in NE Brazil.

  • Advisor : GUILHERME ORTIGARA LONGO
  • COMMITTEE MEMBERS :
  • CARLOS EDUARDO LEITE FERREIRA
  • GUILHERME ORTIGARA LONGO
  • JORGE EDUARDO LINS OLIVEIRA
  • LIANA DE FIGUEIREDO MENDES
  • Data: Feb 22, 2019


  • Show Abstract
  • Natural communities are structured by physical and biological factors that drives local dynamics of species coexistence. On reef habitats, conditions such as current dynamics, waves, temperature, depth and nutrient availability plays an important role on structuring communities. Nutrient availability is a frequent limitation on marine environments. The island mass effect, for instance, when the allochthonous nutrient supply supports a diverse ecosystem, and the transformation of dissolved organic carbon into particulate matter by sponges (sponge-loop) have an important role on maintaining ecosystems on oligotrophic conditions. Most Brazilian reefs are rocky or sandstone formations with a great influence of continental run-off, being mostly dominated by macroalgae and presenting low coral cover. Biogenic reefs in Brazil occur in the Abrolhos bank and southern Bahia state, presenting high coral cover. Recently, biogenic reefs with high coral cover were geologically described on northern Brazilian coast. We described benthic and fish communities in these reefs using photoquadrats of benthic substrates and visual census of fish community. Three reef areas were chosen around an incised valley on marine floor, a potential pathway for nutrient input to the reefs, exploring variations among reefs at east, west and at the center of the valley. We found higher coral cover and lower macroalgae cover on reefs located within the incised valley. Fish biomass was similar among areas, but biomass distribution differed among functional groups. Invertivores and piscivores biomass was greater on reefs within the valley, potentially resulting from higher food availability resulting from increasing nutrient input. Our results reveal that nutrient inputs from incised valleys may structure reef communities similarly to what happen with the island mass effect. This work contributes to description of biological communities composing these recently described biogenic reefs, elucidates the potential effects of the incised valley on these reefs, and fills a gap on the knowledge on these kind of reef formation in Brazil, generating information that can be further used for guiding management and conservation of those unique ecosystems.

2
  • LUIZA SOARES CANTIDIO
  • Atlantic Forest bioregionalization and its relation with environmental factors

  • Advisor : ALEXANDRE FADIGAS DE SOUZA
  • COMMITTEE MEMBERS :
  • ALEXANDRE FADIGAS DE SOUZA
  • VANESSA GRAZIELE STAGGEMEIER
  • GUILHERME GERHARDT MAZZOCHINI
  • Data: Feb 26, 2019


  • Show Abstract
  • Geographic bioregionalization is the practice of delimiting regions based on the distribution of biota in space, generating units that carry biological significance. The increasing modernization of classification techniques and the abundance of data from currently available vegetation inventories are an incentive to the practice of bioregionalization with the use of such data. The objective of this study was to elaborate the bioregionalization of the Atlantic Forest based on data of presence and abundance of plant species, and to identify the environmental and historical factors that structure the distribution of the generated groups. In order to classify the biome into groups, we used sorting and grouping techniques, and to investigate the influence of environmental and historical factors on the groups, we used multinomial logistic regression models. From the presence and abundance data, 21 and 14 groups were generated, respectively.

3
  • ÁTILA DANTAS ESCÓSSIA DE MELO
  • Spatio-temporal variation in fish assemblages of mangrove ponds

  • Advisor : HELDER MATEUS VIANA ESPÍRITO-SANTO
  • COMMITTEE MEMBERS :
  • HELDER MATEUS VIANA ESPÍRITO-SANTO
  • MARIO BARLETTA
  • TOMMASO GIARRIZZO
  • Data: Mar 1, 2019


  • Show Abstract
  • Intertidal mangrove forests play important roles for especies persistence, providing food and shelter from predators for marine and estuarine small fishes. Despite the great progress in knowledge of estuarine and mangrove systems in the last decades, little is know about fish community dynamics in the temporary enviroments of mangroves. The present study aims for understand how fish species are distributed inside the mangrove forest in temporary ponds along the estuary (spatial dynamics), between seasonal surveys (temporal dynamics) and according to microhabitat characteristics. Field work was conducted from november 2017 to september 2018 on the Ceará-Mirim river mangrove (Northeastern Brazil). We stabilished 17 10m x 10m quadrats distributed along the estuary, which were used as sample units. Our fish collection followed a standardized protocol. Limnologic and microhabitat variables (density of roots, ponds, crab burrows, propagules, canopy cover and pond number and depth) were mesured. 1189 individuals belonging to 10 species were collected. with Kryptolebias hermaphroditus being the dominant species (52% of total fish abundance), followed by Poecilia vivipara (24%), Ctenogobius smaragdus (11%), Ctenogobius shufeldti (2%), Ctenogobius boleosoma (2%), Evorthodus lyricus (3%), Dormitator maculatus (<1%), Eleotris pisonis (1%), Guavina guavina (4%) and Erotelis smaragdus (<1%). Abundance, richness and diversity increased in the rainy months. P. vivipara and Gobiidae species followed this pattern, with major abundances in this period. K hermaphroditus and Eleotridae species were more constant. We found a inverse relationship between diversity and abundance along the estuary, with major diversity and minor abundance occurring closer to de ocean, in constrast with upper areas with minor diversity and major abundance. P vivipara occured more in the upper areas of the estuary, while C. boleosoma and E. pisonis tended to occur more in areas close to ocean. Other species were more constant. The different microhabitat characteristics within the mangrove forest were also important in species distribution. We found evidences that the fish assemblages in the mangrove forest are modulated by rainfall cycle, the closeness to the ocean and to microhabitat characteristics and discuss these findings in light of the current knowledge on mangrove fish.

4
  • RAYANE FERNANDES VANDERLEY
  • Abiotic driving factors of phytoplankton structure community and cyanobacteria dominance in tropical semiarid reservoirs

  • Advisor : RENATA DE FÁTIMA PANOSSO
  • COMMITTEE MEMBERS :
  • JULIANA DEO DIAS
  • RENATA DE FÁTIMA PANOSSO
  • ROSEMBERG FERNANDES DE MENEZES
  • VANESSA BECKER
  • Data: Mar 25, 2019


  • Show Abstract
  • Harmful cyanobacterial blooms are one of the most severe problems in freshwater ecosystems and since the mid-20th century has become more recurrent due to anthropic disturbances. Some waterbodies face permanent cyanobacterial blooms, such as many semiarid reservoirs in Brazil, and the drivers regulating bloom formation are still poorly understood. Comprehend these regulators are crucial to develop an effective management strategy, macronutrients levels and light have been considered key factors to comprehend cyanobacteria blooms dynamics. Despite this, in environments that are constantly enriched and illuminated, other factors should regulate the permanent blooms of cyanobacteria. In light of this, the aim of the present study was to evaluate the abiotic drivers of (1) phytoplankton total biomass; (2) phytoplankton community structure based in functional traits and (3) cyanobacteria dominance. Water from six reservoirs located in the semi-arid region from Brazil was sampled during 12 months for analyses of limnological parameters, nutrient, and phytoplankton density and biomass. Species were classified into morphologically based functional groups (MBFG).  Four reservoirs were characterized as eutrophic and two of them as mesotrophic. Depth, total phosphorous and temperature were the mean variables driving phytoplankton biomass. In addition, the use of MBFG was efficient to access the trophic state of the reservoirs. Light and nutrients explained the dominance of different genus of cyanobacteria. Overall, light and macronutrients partially explained the structure of the phytoplankton community and cyanobacteria dominance, this may indicate that the influence of nutrients on assemblage’s structure is weaker in environments enriched. We suggest that biological interactions, such as competition, allelopathy and grazing, could be a significant driver shaping the phytoplankton community in environments that are permanently enriched and dominated by cyanobacteria.  

5
  • VICTORIA HELEN FIGUEIREDO PAIXÃO
  • BIOLOGY AND REPRODUCTIVE SUCCESS OF COCCYZUS MELACORYPHUS (AVES: CUCULIDAE) IN A CAATINGA AREA.

  • Advisor : MAURO PICHORIM
  • COMMITTEE MEMBERS :
  • ANDROS TAROUCO GIANUCA
  • LEONARDO FERNANDES FRANÇA
  • MAURO PICHORIM
  • Data: Mar 27, 2019


  • Show Abstract
  • The Dark-billed Cuckoo (Coccyzus melacoryphus) is a species of 136 species of the Cuculidae family, which occurs throughout Brazil. In part of its distribution performs periodic movements, as in the Caatinga. In Rio Grande do Norte, its period of permanence is related to rainy season, occurring between the months of February and June when they arrive to reproduce. Studies on the reproductive dynamics of birds in seasonal environments have been focused in temperate regions, generating a knowledge gap for neotropical regions. This research tries to understand more about the reproductive dynamics of birds from seasonal environments, describing aspects of The Dark-billed Cuckoo’s breeding biology: reproductive period, nest and egg description, posture size, incubation and nesting period. We monitored nests at intervals of 2-3 days in the Estação Ecológica do Seridó – ESEC-Seridó, during the rainy season of 2017 and 2018. We recorded 63 nests of The Dark-billed Cuckoo, 31 between March 1 and May 8, 2017 and 32 nests between February 8 and June 10, 2018. The nests were built on shrubs and trees at a mean height of 1.61 ± 0, 88 m, and the pereiro tree (Aspidosperma pyrifolium) was the main plant used as support. The nests showed a “simple/platafformformat, with sticks showing a tendency to present the outer ones larger in length and diameter than the inner ones. The eggs were short subelliptical with light green coloration (color 81 Pearl Gray by Smithe 1975). The eggs mean weight was 9.7 ± 0.9 g, the length was 28.4 ± 1.5 mm and width was 22.1 ± 1.5 mm. The mean number of nestlings per nest was 2.60 ± 0.96 (n = 32). In its breeding biology, we believe that The Dark-billed Cuckoo acts like the other members of the genus, presenting a long reproductive period when compared to birds of temperate regions, with a probable short period of incubation and of the nestlings’ permanence.

6
  • ADRIANO SOARES MOTA
  •  

    EFFECTS OF HABITAT IDENTITY AND DIVERSITY ON LITTER DIVERSITY-DECOMPOSITION RELATIONSHIP

  • Advisor : ADRIANO CALIMAN FERREIRA DA SILVA
  • COMMITTEE MEMBERS :
  • ADRIANO CALIMAN FERREIRA DA SILVA
  • ALEXANDRE FADIGAS DE SOUZA
  • JOSÉ LUIZ ALVES SILVA
  • Data: Mar 28, 2019


  • Show Abstract
  • A growing number of empirical evidences have pointed to the importance of the litter diversity as mediating factor of the decomposition process in terrestrial ecosystems. At the same time, studies have shown that both identity and habitat diversity can also interfere in the dynamics of determinants of ecosystem processes, such as decomposition. However, little is known, whether and how factors such as habitat identity and diversity operate individually and interactively to the effects of the litter diversity on decomposition. In a restinga forest located in the northeastern coast, we evaluated experimentally over 8 months, if and how the effects of the litter diversity on decomposition varied according to the identity and diversity of habitats, as well as the occurrence of non-additive effects diversity of individual habitats. For this, a functional diversity gradient of litter was established through the allocation of detritus of five local tree species in microcosms formed by monocultures and all possible combinations of two species, totaling 15 different compositions (5 monocultures + 10 mixtures). This experimental design was replicated orthogonally along two levels of identity (i.e., above and belowground) and diversity (i.e. presence or absence of adjacent habitat) of habitats. The results showed that the litter richness explained most of the variation in the decomposition process, but that its effects were also significantly mediated by habitat identity, and for most species the litter diversity exerted an effect habitat above the ground. Habitat diversity did not have a significant effect on the decomposition process either individually or interactively with the litter diversity. In addition, functional diversity also did not affect decomposition in a systematic way in any type of habitat and also did not interact with the diversity of habitats. Our results demonstrate that particular characteristics of soil habitats can mediate the effects of the litter diversity on decomposition. However, these effects seem to occur independently of each habitat type (i.e., absence of interactive effects between habitats). In addition, the lack of effects of functional diversity confirms the results of recent studies in the literature that characteristics of functional identity (i.e., interactions between particular functional traits of the community) are more prevalent than systematic effects of the functional diversity of litter on decomposition.

7
  • ANDRÉ YURI SANTOS PORTIOLE BELO
  • Do litter diversity effects on decomposition vary between environments where decomposition is regulated by abiotic vs biotic mechanisms? The importance of functional of functional traits sensitive to photodegradation and the litter positioning in the litter bed

  • Advisor : ADRIANO CALIMAN FERREIRA DA SILVA
  • COMMITTEE MEMBERS :
  • ADRIANO CALIMAN FERREIRA DA SILVA
  • LUCIANA SILVA CARNEIRO
  • JOSÉ LUIZ ALVES SILVA
  • Data: Apr 5, 2019


  • Show Abstract
  • Studies over the last two decades have pointed to an important role of the litter diversity, especially the functional one, as a determinant of decomposition rates. So far, it has been known that the mechanisms by which the diversity of litter affects decomposition results from biotic mechanisms mediated by the interactions between the decomposing fauna and the detritus. However, abiotic factors such as photodegradation also have a direct effect on decomposition rates in many ecosystems, especially in regions or habitats with a high incidence of UV radiation. In this way, it is conjectured that non-additive effects of the debris diversity in the decomposition should be weak or nonexistent under environmental conditions that do not favor the decomposition through biotic mechanisms. In this work, we tested this conjecture through two field experiments carried out under distinct environmental contexts, in a restinga in the State of Rio Grande do Norte. In the first experiment (Exp. 1), we verified whether and as non-additive effects of the richness and functional diversity of litter vary in magnitude and direction between a habitat more conducive to decay-mediated decomposition (ie soil under vegetation) and another where Photo-degradation-mediated decomposition assumes greater relevance (ie soil exposed to direct solar radiation). In the second experiment (Exp. 2), we observed only in the habitat with high solar exposure if and as the overlap (ie overlapping or not between) and the position with which the litter is vertically in the litter (ie in contact with the soil , or on the litter surface) measured the effects of the diversity of debris on decomposition. In the Exp. 1 litter of four species, presenting discrepant values of specific leaf area (AFE) were placed to decompose in monocultures and all possible bicultures over 6 months in litterbags. In Exp. 2 the decomposition was also evaluated in litterbags over 6 months, but only for monocultures and mixtures formed by two species that presented more discrepant values of AFE, Erythrina velutina (Ev) and Sterculia chicha (Sc). The results of Exp. 1 showed that the rate of decomposition at sites exposed to the direct action of photodegradation was on average 34% higher than that observed in shaded sites under vegetation. There was no significant effect of species richness on decomposition in any of the environmental contexts, indicating that on average the decomposition of the detritus mixtures can be predicted through the decomposition of their monocultures. However, this effect was not homogeneous among the bicultures. The functional dissimilarity between the bicultures had a significant effect on the decomposition, but only in the environment exposed to the sun. In general, combinations of foliar litter with greater discrepancy in the AFE values presented slower decomposition in bicultures than in monocultures. This result was mediated by a trade-off between effect and response of the debris of different species to shade. Species with higher AFE were more sensitive to shading, while species with lower AFE had a greater shading effect. In addition, in Exp. 2 we observed that the overlap and vertical positioning of the detritus also modify the effects of diversity on decomposition. Effects of the debris diversity on decomposition occurred only in the treatments with overlapping litter. However, the effects were significant only for the S. chicha (Sc) species, whose decomposition in the near-soil (less exposed to the sun) and surface (more exposed to the sun) differed from their monoculture decomposition (ie major and minor respectively ). Contrary to our expectations, abiotic mechanisms from photodegradation determine non-additive effects of the functional diversity of debris that consistently retard decomposition in environments exposed to the sun, but such effects have been shown to be dependent on the vertical position of the debris in the litter. Together, the results show that the functional diversity of the detritus, as well as factors that determine the vertical position of the debris in the litter (ie phenological pattern) can act as important mechanisms of carbon retention in the soil in regions, ecosystems or habitats, with high exposure solar

8
  • MARINA SILVA MOURA
  • Effect of plant diversity on the insect community in a Caatinga restoration program

  • Advisor : GISLENE MARIA DA SILVA GANADE
  • COMMITTEE MEMBERS :
  • EDUARDO MARTINS VENTICINQUE
  • GISLENE MARIA DA SILVA GANADE
  • GUILHERME GERHARDT MAZZOCHINI
  • Data: Apr 11, 2019


  • Show Abstract
  • Forest restoration experiments are of great importance for the recovery of degraded areas of Caatinga, providing the development of new restoration technique. A possible approach to evaluate the success of restoration techniques would be to understand the way tree species diversity would affect the colonization of degraded areas by other trophic levels, such as insects. This work aims to analyse how plant diversity in restored plant communities influence insect colonization during the initial stages of restoration. The study was conducted at the National Forest of Açu (RN, Brazil). The experiment was implemented in 2016, for the restoration of a Caatinga area, in which 4,704 seedlings of 16 native tree species were planted. The species were distributed in 155 plots of 8 x 13 m implemented using five levels of plant diversity: 1 species, 2 species, 4 species, 8 species and 16 species, per plot. In the rainy session of 2017, June and July, all plants were surveyed and the insects found  were manually collected, stored and identified. To understand the relationship between plant diversity and insect richness and abundance, factorial ANOVAs were performed. A total of 799 insects were collected and 66 OTUs registered. Insect diversity and abundance were significantly higher when plant diversity was higher (8 and 16 species). In addition, the leguminous tree species Mimosa tenuiflora and Piptadenia stipulacea were more attractive to insects than the other plant species studied. We conclude that restoration plots planted with high plant species diversity improved the colonization of new trophic levels. Therefore, planting using high plant diversity might be a promising technique for Caatinga restoration.

9
  • FÁBIO HENRIQUE DANTAS DE CARVALHO
  • HISTORICAL RESCUE AS A TOOL TO REBUILD THE PASSED ABUNDANCE OF SHARKS ON THE COAST OF THE BRAZILIAN NORTHEAST

  • Advisor : PRISCILA FABIANA MACEDO LOPES
  • COMMITTEE MEMBERS :
  • PRISCILA FABIANA MACEDO LOPES
  • GUILHERME ORTIGARA LONGO
  • RONALDO ANGELINI
  • ANTOINE LEDUC
  • ANA HELENA VARELLA BEVILACQUA
  • Data: Apr 23, 2019


  • Show Abstract
  • Knowing the situation of fish stocks is essential for the management and maintenance of fisheries. However, in Brazil little is known about most stocks, even those of interest to small-scale fisheries. In the absence of this information, historical surveys using interviews with fishers and other groups of people that directly observe fishing resources (e.g., researchers and divers) serve as a tool to evaluate the actual trends of these stocks. Nevertheless, there may be a common distortion associated with this methodology, known as the shifting baseline syndrome. In this syndrome, the informant tends to believe that the moment he or she began to observe the resource, the resource was at its peak of abundance, which disregards past exploitations and can lead to a false perception of the current state of the stocks. One way to alleviate this distortion is to include informants of different ages and experiences, seeking to retrieve the oldest information possible. The general objective of the present research was to do a historical survey of the sighting of some species of sharks by artisanal fishers on the northeastern Brazilian coast, evaluating possible changes in shark occurrences and their sizes along the last six decades, using for that information provided by artisanal fishers. The data were collected along part of the northeastern coast (states of Rio Grande do Norte, Paraíba, Pernambuco and Bahia). Out of the eight species analyzed, in three (Carcharhinus leucas, Ginglymostoma cirratum and Sphyrna lewini) the fishers perceived a decreased in their maximum size over the years. Coastal species were the most likely to suffer from these size variations. The different groups of fishers, classified into age groups, had different perceptions of the average sizes of the species Carcharhinus leucas and Isurus oxyrinchus. With the ever-increasing risk of extinction of large predators, we hope to contribute to the understanding of the patterns of abundance and size changes of fish and their stocks over the recent past through the knowledge accumulated by fishers.

10
  • BRUNA LAYZ CARVALHO DE MELLO
  • THE ROLE OF CLIMBING PLANTS AND HERBIVORY ON THE RESTORATION SUCCESS OF CAATINGA PLANT COMMUNITIES

  • Advisor : GISLENE MARIA DA SILVA GANADE
  • COMMITTEE MEMBERS :
  • GISLENE MARIA DA SILVA GANADE
  • ADRIANA PELLEGRINI MANHÃES
  • MARINA ANTONGIOVANNI DA FONSECA
  • Data: Apr 30, 2019


  • Show Abstract
  • Semi-arid ecosystems are highly susceptible to landscape degradation. Among them, the Caatinga is one of the most vulnerable regions. Caatinga restoration has advanced with new successful methods like the use of facilitation and new techniques of planting. Nevertheless, there are after planting problems that interfere with restoration program success, such as climber plant interference and insect herbivory, which frequently have negative impact on transplant survival and growth. This work aims to investigate how insect herbivores and plant climbers affect growth and survival of different native tree species planted in a restoration project implemented at a degraded area of Caatinga. Sixteen native tree species from Caatinga were planted in 147 plots with 5 diversity levels: 1, 2, 4, 8, 16 species. Seedlings were monitored over a two years period. For all planted individuals we measured survival, growth, incidence of leaf herbivory and incidence of plant climbers. Survival differed between species, however, four species had their survival impaired by the incidence of climbers. Climber occurrence did not affect the growth of any transplanted species. Herbivory has positively affected the survival of two species while one species had its survival negatively affected. Regarding growth, the incidence of herbivory positively affected only one of the studied species. Neither diversity nor its interaction with herbivory and climbers affected tree growth and survival during the initial stages of Caatinga restoration. Because only one plant species was affected by herbivory, we suggest that no method of herbivory control should be applied in the first years of Caatinga restoration, but if applied methods should target the most sensitive species. This work suggests that species diversity does not have a relevant role on the early phases of restoration regarding its influence on survival, growth, incidence of climber and incidence of herbivory of transplanted plants. This experiment shows that plant climbers can have a negative effect on survival of transplanted tree saplings, even after frequent removal management. Therefore, new techniques to control plant climbers should be developed in future Caatinga restoration projects.

11
  • LUIS WAGNER FERREIRA GUIMARÃES
  • Populational Biology of the Goiamum Crab in areas of different profiles of use and occupation of a Marine Extractive Reserve

  • Advisor : FULVIO AURELIO DE MORAIS FREIRE
  • COMMITTEE MEMBERS :
  • FULVIO AURELIO DE MORAIS FREIRE
  • ROSANGELA GONDIM D OLIVEIRA
  • TIEGO LUIZ DE ARAÚJO COSTA
  • Data: May 31, 2019


  • Show Abstract
  • Extractive Reserves are conservation units whose objective is to guarantee the sustainable use of natural resources by traditional extractive populations. The Acaú-Goiana Extractive Reserve is located in the estuary of the Goiana river, on the border of the states of Paraíba and Pernambuco, and involves areas of Atlantic forest, restinga, mangroves and apicums, being an important supplier of fishery resources such as Goiamum (Cardisoma guanhumi LATREILLE, 1828). The goiamum inhabits mainly the transition areas between the mangroves and areas of forest or restinga, known as apicuns. Due to the intense fishing exploitation and the marked degradation of its occurrence, C. guanhumi has been included in the list of endangered species, which imposes a series of restrictions of use and management measures aimed at the recovery of the populations and their habitat. Thus, the present work aims to analyze the population and fishing dynamics of the species, comparing areas of family farming (very common in the reserve) and preserved areas, aiming to subsidize effective management measures for the species in a territory with multiple anthropic activities. To date, 1619 burrows were sampled in the area and 500 animals were analyzed in the laboratory. The results indicated that there were significant differences between the two sampled areas in relation to the abundance of occupied burrows (ꭓ² = 12,929, df = 3, p <0.01), as well as in the carapace width - CW (ꭓ² = 1,186, df = 1, p <0.001) and weight (ꭓ² = 34,950, df = 1, p <0.001) of the subjects. However, there were no differences in burrow densities, abundance of empty burrows, moulting, and captured animals. There was also no difference in gonadal maturity size, LCxPeso ratio and condition factor between areas of agriculture and preserved areas. C. guanhumi is a generalist species, able to survive in environments altered by humans. However, management measures are necessary in relation to the zoning of agricultural activities, as well as the techniques and types of cultivation, which minimize the suppression of habitats and allow a greater growth and conservation of the species.

12
  • CLARA DANTAS NAVARRO
  • Effects of application of polialuminium chloride (PAC) and benthivorous fish removal on benthic macroinvertebrates assemblages of a shallow eutrophic lake

  • Advisor : JOSE LUIZ DE ATTAYDE
  • COMMITTEE MEMBERS :
  • JOSE LUIZ DE ATTAYDE
  • ROSEMBERG FERNANDES DE MENEZES
  • VANESSA BECKER
  • Data: Jun 25, 2019


  • Show Abstract
  • The application of aluminum salts and the removal of benthivorous fish are two techniques of water quality management of eutrophic lakes that tend to reduce the internal contribution of phosphorus from the sediment to the water column and to mitigate the effects of eutrophication. However, the isolated and combined effects of these two management techniques on the structure and dynamics of aquatic communities are poorly understood. The application of aluminum polychloride (PAC) increases the flow of organic matter from the water column to the sediment, increasing the availability of detritus to benthic invertebrates, while the removal of benthic fish reduces competition and / or predation pressure on themselves. Therefore, the increased availability of detritus should have a stronger positive effect on benthic macroinvertebrates in the absence than in the presence of detritus-eating benthivorous fish and therefore we should note a synergistic effect of the two techniques on the density and diversity of these organisms. To test this hypothesis, a field experiment with a 2 x 2 factorial design was carried out, combining the application or not of PAC with the presence and absence of the benthivorous fish Prochilodus brevis, a very common and abundant detritus species in the Brazilian semiarid reservoirs . The experiment was carried out in 20 mesocosms of 6 m 3 inserted in a tropical semiarid lake and the 4 treatments were randomly allocated in the mesocosms. Water and sediment samples were collected in each mesocosm at the beginning, middle and end of the experiment, which lasted 8 weeks. The benthic macroinvertebrates were identified and quantified in each sample and the density data of these organisms were treated with a two-way ANOVA. The techniques of water quality management and the interaction between them did not present effects on the benthic macroinvertebrates. Therefore, the results refuted the hypothesis of research, and suggest that the high availability of organic matter, typical of eutrophic environments, determines the lack of effect of the two techniques on benthic macroinvertebrates assemblages.

Thesis
1
  • ALINA ROCHA PIRES BARBOZA
  • BENTHIC MOLLUSCS AND ECHINODERMS IN TROPICAL SANDSTONE REEFS: METHODS EVALUATION AND COMMUNITY STRUCTURING

  • Advisor : TATIANA SILVA LEITE
  • COMMITTEE MEMBERS :
  • CARLOS EDUARDO ROCHA DUARTE ALENCAR
  • CRISTIANE XEREZ BARROSO
  • EDSON APARECIDO VIEIRA FILHO
  • JULIANA DEO DIAS
  • ROSANGELA GONDIM D OLIVEIRA
  • Data: Feb 1, 2019


  • Show Abstract
  • Intertidal rocky environments are important feeding, growth and reproduction areas to a variety of benthic organisms, including molluscs and echinoderms. They can be found worldwide and their benthos’ composition and temporal and spatial patterns are influenced by environmental and biological factors. Nevertheless, most studies on these environments have focused on rocky shores of temperate and subtropical regions. On the other hand, there is a lack of studies in other rocky formations and tropical regions, specially testing proper methodologies to their unique characteristics. This study had three main objectives: 1) to identify the main types of method used for quantifying benthonic organisms, through scientometric analysis; and, in tropical sedimentary reefs: 2) to test random and stratified quadrats and transects with quadrats to test the survey method that best represent richness of molluscs and echinoderms in these environments; 3) and, after defining the most suitable survey method, to test which environmental factors influence occurrence, abundance and richness of these organisms, and testing whether these is seasonal variation of occurrence of species. The organisms’ mobility is one of the determinant factors when choosing benthonic survey method. Quadrats and transects with quadrats were the main methods used to delimit areas of countage of mobile individuals and estimation of sessile cover. Random transects with quadrats showed better richness results with less collection effort, including sampling under boulders when they were present. Substrate cover, reef typology, habitat complexity and exposure time were the main environmental factors determining the structure of communities over the reefs. Substrate cover, habitat complexity and exposure time were the main structurers of communities under boulders. The abundance of organisms of the studied communities varied between dry and rainy stations, although this only occurred within a few taxa. 

2
  • CAROLINA TAVARES DE FREITAS
  • The arapaima (Arapaima sp.) management in the Amazon: ecological and socioeconomic aspects

  • Advisor : PRISCILA FABIANA MACEDO LOPES
  • COMMITTEE MEMBERS :
  • PRISCILA FABIANA MACEDO LOPES
  • ALEXANDRE SCHIAVETTI
  • JUAREZ CARLOS BRITO PEZZUTI
  • LEANDRO CASTELLO
  • NATALIA HANAZAKI
  • Data: Mar 28, 2019


  • Show Abstract
  • Since the 1980s, the participatory management (collaborative management) of natural resources has been increasingly adopted in management systems around the world. This type of management represents the transition from a centralized control to a more democratic and inclusive arrangement in which local people have the right of participating in the decision making and control of resource use. Despite the increasing number of collaborative management systems being implemented worldwide, the establishment of these systems often occurs without any theoretical basis on aspects related to the success or failure of the initiatives. Furthermore, scant attention is given to the social and economic dimensions, even if they are spheres of great importance, and directly related to the ecological success. In the Amazon, several collaborative management regimes have already been implemented - among them, the arapaima management has had great repercussions in recent years. The arapaima (Arapaimaspp.) is one of the largest freshwater fish in the world, and is an element of great ecological, economic and cultural importance in the Amazon. Although it used to be the main fishing resource of the Brazilian Amazon for more than a century, little is known about the arapaima populations’ historical due to the lack of fishery statistics. However, in light of some evidence of over-exploitation, arapaima fishing has been banned, and is currently allowed only under a management plan approved by the government. The arapaima management initiatives are proliferating throughout the Amazon, and seem to be promoting both the increase of the stocks, and socioeconomic benefits. This study aims to (1) evaluate the benefits of using culturally important species, such as the arapaima, as umbrella species in management plans and conservation of natural resources; (2) to evaluate patterns of change in the abundance and size of arapaima over time; (3) to estimate the economic impact of the arapaima management for rural families inside and outside Conservation Units; (4) to verify the impact of the arapaima management in increasing gender equity in fisheries through the recognition of women participation. Each of these objectives corresponds to a chapter of the thesis. The data for the first chapter were obtained from the literature, while the others chapters were based on data from semi-structured interviews with fishermen living in communities from three Amazonian rivers’ basins. With our results we expect to provide subsidies and incentives for the development of more effective natural resource management systems seeking to reconcile ecological and socioeconomic sustainability.

3
  • MARIANA RODRIGUES AMARAL DA COSTA
  • PHYTOPLANKTON MIXOTROPHY ACROSS NUTRIENT AND LIGHT GRADIENTS

  • Advisor : VANESSA BECKER
  • COMMITTEE MEMBERS :
  • VANESSA BECKER
  • JULIANA DEO DIAS
  • HUGO MIGUEL PRETO DE MORAIS SARMENTO
  • IRINA IZAGUIRRE
  • KEMAL ALI GER
  • LUCIANE OLIVEIRA CROSSETTI
  • Data: Apr 26, 2019


  • Show Abstract
  • Precipitation events and water level fluctuations are environmental factors that affects aquatic ecosystem functioning influencing phytoplankton dynamic and their resources. Nutrient availability and trophic state of arid and semi-arid regions are controlled by quantity and rain periodicity. Future climate scenario predicts an increase in intensity and frequency of droughts in semi-arid regions. Drought leads to water level reduction and consequently increase nutrients concentrations, turbidity, salinity and conductivity, favoring cyanobacteria blooms. However, recent studies shows that mixotrophic algae can be better competitors under more extreme conditions, such as prolonged periods of droughts. Mixotrophic organisms play important role as producers and consumers reflecting in the structure of food webs. In this work, we evaluate the effect of precipitation gradient in semi-arid region on the structure of phytoplankton community based on a trait-based approach. We confirm the hypothesis that in dry period the main phytoplankton traits are related to a high cyanobacteria biomass (nitrogen fixation, filaments, coloniality), however, in extremely drought periods with critical water level, cyanobacteria collapse and shifts the dominance to mixotrophic algae. To confirm that the reduction on light availability caused by sediment resuspension was the main factor on phytoplankton pattern, we performed laboratory experiments with competition between cyanobacteria and a mixotrophic species, manipulating light and sediment addition in systems with high levels of nutrients. Besides this, we also performed grazing experiments to estimate bacterivory by flagellate algae in distinct light and nutrients conditions and propose new methodologies to facilitate ingestion rates quantification. Our study shows the importance of mixotrophic algae in eutrophic environments, such as semi-arid systems affected by hydric deficit, and compare methodologies in order to facilitate bacterivory rates quantification, allowing a better knowledge about this kind of mixed nutrition. Therefore, research about mixotrophy implies in paradigmatic changes in how we understand aquatic food webs nowadays, in particular this is even more critic when it links to shifts in environmental conditions in a changing climatic world.

4
  • NATÁLIA CARVALHO ROOS
  • Brazilian parrotfishes: from assemblages to individuals 

  • Advisor : ADRIANA ROSA CARVALHO
  • COMMITTEE MEMBERS :
  • ADRIANA ROSA CARVALHO
  • BEATRICE PADOVANI FERREIRA
  • JORGE EDUARDO LINS OLIVEIRA
  • ROBERTA MARTINI BONALDO
  • RONALDO BASTOS FRANCINI-FILHO
  • Data: Apr 30, 2019


  • Show Abstract
  • Parrotfishes may affect the structure of benthic communities and reef ecosystem functioning. Despite being extensively studied worldwide, parrotfishes in Southwestern Atlantic are relatively understudied and critical information to understand their functional roles is scarce. The abundance, biomass and size class distribution of parrotfish assemblages in Northeast Brazil were assessed and habitat preferences were identified based on reef attributes. Benthic cover, reef structural complexity, depth and distance from the coast affected the composition of parrotfish assemblages, but had different effects on each species. The occurrence, abundance and biomass of the endemic greenbeak parrotfish Scarus trispinosus were associated to calcareous substrates and higher-complexity reefs. Sc. zelindae and Sparisoma amplum were more common in deeper biogenic reefs further from the coast, covered by sponges, stony corals and cyanobacterial mats. Sp. axillare and Sp. radians were associated to reefs with high cover of large-bladed macroalgae, while Sp. frondosum was conspicuous across all the studied reefs. Outer-shelf reefs sustained larger-sized individuals and higher biomasses of all species (except for Sp. radians), while inner-shelf reefs concentrated higher abundances of small-sized individuals. This may result from juvenile parrotfish preferring shallow inshore reefs as nursery areas, but also from fishing activities depleting larger-sized individuals in more coastal reefs. Habitat preferences of bioeroder excavating parrotfishes (Sp. amplum and Sc. trispinosus) differed from the grazing sparisomatines, likely because of their different nutritional targets and grazing capacity. Our results that: (1) functional role of parrotfishes in structuring benthic communities is variable and potentially predicted by reef attributes; (2) there may be more complementarity than redundancy occurring among the Brazilian endemic parrotfish; and (3) inshore and offshore reefs may be distinct with respect to maturation schedules and rates of mortality, what should be taken in account in management planning. Conservation of Brazilian endemic parrotfishes requires protecting reefs with diverse attributes, including the protection of inshore reefs that are potentially nurseries habitats.

     

5
  • ÁLVARO CARVALHO DE LIMA
  • Excretions of Amazonian fishes using Ecological Stoichiometry and Metabolic Theory of Ecology approaches

  • Advisor : RONALDO ANGELINI
  • COMMITTEE MEMBERS :
  • CARLOS EDWAR DE CARVALHO FREITAS
  • GUILHERME GERHARDT MAZZOCHINI
  • JOSE LUIZ DE ATTAYDE
  • RAFAEL DETTOGNI GUARIENTO
  • RONALDO ANGELINI
  • Data: May 30, 2019


  • Show Abstract
  • Fishes are important to uptake processes as well as energy and nutrients transfer in aquatic food webs. Fish excretion supplies nutrients for autotroph organisms, representing the main source of nitrogen and phosphorous for primary producers in several freshwater ecosystems. Body size, diet, as well as environment light-nutrient conditions, affect excretion rates and ratios of nutrient recycled by fish. The Amazon basin encompasses the most diverse fish fauna in the world, however nutrient recycling by fish in that ecosystem had never being surveyed so far. The main purpose of this thesis was to assess nitrogen and phosphorus release by fish, measuring their excretions in field conditions. One hundred fifty-three incubation experiments were performed using 59 native species. This thesis is structured in five sections: the first one presents a general introduction; the second section describes the study area, and methods used to get field data and the laboratory analysis; The third section deals about the results, which are presented in form of two independent chapters, each one with a brief contextualization about the problem addressed, results and discussion. The fourth and fifth sections, respectively, present a general conclusion and all the references cited. The main two results showed that: 1) excretion rates were negatively related to body mass and body stoichiometry, while excreted N:P ratio was positively related to body mass. We could reveal the indirect effect of body mass on excretion because body mass also affects body stoichiometry; 2) we used literature data to create a proxy to growth rate, assuming the fish growth is faster as smaller they are far from their maximum size, than we compared body stoichiometry and excretion ratios of juvenile in contrast to adult fishes. Results revealed that growth affects body stoichiometry and excretion ratios in the beginning of the juvenile phase. Overall, our conclusions point out that body size, body stoichiometry and growth affect N and P release by fishes.   

6
  • FELIPE PEREIRA MARINHO
  • Influence of functional traits on plant fitness in response to drought and aboveground biomass removal

  • Advisor : GISLENE MARIA DA SILVA GANADE
  • COMMITTEE MEMBERS :
  • CARLOS ROBERTO SORENSEN DUTRA DA FONSECA
  • GISLENE MARIA DA SILVA GANADE
  • GUILHERME GERHARDT MAZZOCHINI
  • LEONARDO HENRIQUE TEIXEIRA PINTO
  • MARCIO ZIKAN CARDOSO
  • Data: May 31, 2019


  • Show Abstract
  • Biotic and abiotic stressors reduce plant productivity through of changes in levels of limiting conditions affecting important functions such as photosynthesis. Drought and aboveground biomass (AGB) removal by land use activities are two recurrent stresses in semiarid environments. However, effects of these stresses applied simultaneously on plant growth is still poorly understood. The purpose of this thesis is to understand the response of plants to water stress and aboveground biomass (AGB) removal, besides to identifying functional traits that promote resistance to these stresses. The thesis is structured in four chapters: 1) which leaf traits are related to the plant susceptibility to grazing by goats, 2) How the combination between AGB removal and water stress affect the biomass growth and non-structural carbohydrates contents (starch and non-reducing sugars) in plants, 3) As functional traits are related with resprouting vigor in different Caatinga plant species, and 4) How non-structural carbohydrate content in leaves and roots affect the survival and biomass recovery of plants in a restored system. In the first chapter it was verified that although the domestic goat be a generalist herbivore, juvenile plants of the Caatinga presented foliar traits that promote resistance to grazing or minimize the chances of being grazed. In the second chapter we verified that water stress and AGB removal reduced the growth rates in Mimosa tenuiflora saplings and that the magnitude of the effects were similar between the two applied stresses. When applied simultaneously the stresses showed a strong reduction in the growth rates and the root starch content. In the third chapter it was verified that the resprouting capacity in Caatinga species is mainly related to storages of non-structural carbohydrates in leaves and roots. These results demonstrate that herbivory pressures by exotic animals when practiced in low rainfall years may prevent the regrowth and recovery of important root reserves for survival during the dry season.

7
  • PHOEVE MACARIO
  • Population and reproductive parameters of granivorous birds in the Caatinga: life strategies in a seasonally dry tropical environment

  • Advisor : MAURO PICHORIM
  • COMMITTEE MEMBERS :
  • MAURO PICHORIM
  • VANESSA GRAZIELE STAGGEMEIER
  • ANA MARIA DE OLIVEIRA PASCHOAL
  • ANGELICA MARIA KAZUE UEJIMA
  • Luciana Vieira de Paiva
  • Data: Jun 28, 2019


  • Show Abstract
  • The establishment of patterns that explain latitudinal variations in avian life history is based on data from tropical rainforests, and there are gaps regarding the evolution of their traits in seasonal tropical environments. The strong seasonality of these environments is related to the rainfall regime, with wet and dry seasons well-marked. In addition, they have atypical climatic variation, exhibiting cycles with prolonged dry periods. As consequence, they limit the availability of food, shelter and nesting sites, altering the dynamics of bird populations. The effects of these periods reflect what is to come in a scenario of global climate change, where is foreseen the increase of shorter rainy seasons. Thus, it is important to understand the strategies of bird populations to keep up with seasonality, and how they respond to severely dry periods, especially granivorous, which are among the most abundant species in such environments. The Caatinga is an example of a tropical seasonally dry ecosystem. This domain presents a variable and stressful rainfall regime, where in many regions annual rainfall does not exceed 500 mm. Therefore, the aim of this thesis was to estimate population and reproductive parameters of granivorous birds in a Caatinga area, during and after a severely dry period. We developed the study at the Estação Ecológica do Seridó, city of Serra Negra do Norte, RN, Brazil. The thesis is structured in three chapters. In Chapter 1, we estimated detection and survival rates of the passerine Ammodramus humeralis. We tested the hypotheses that apparent survival would be lower than that described for tropical rainforests, influenced by seasonality and negatively affected by the prolonged dry period. To analyze the data, we used Huggins' robust design model in the MARK program. Contrasting our hypotheses, the best fit model considered apparent survival as constant, and the annual estimates among those observed in rain forests. We believe that the population studied here was able to maintain a constant survival, even in the face of a period where resources were severely scarce, because they did not reproduce. Since reproduction involves an energy cost, not reproducing compensates the waste that reduces survival rates. In chapter 2, we describe reproductive characteristics (egg size and weight, incubation and nestling period, nest density and behavioral traits) of Columbina minuta and Columbina picui. We also estimated nest daily survival rates (TSD) investigating whether the height, plant support, camouflage, stage (egg or nestling) and nest age influence this parameter. From it, we obtained rates of reproductive success and predation. We evaluated the hypothesis that TSD would be affected by environmental characteristics, higher during the nestling stage, and that predation would be lower than other orders species. We used the Mayfield method and developed nest survival models in the MARK program for data analysis. We verified that both species nest in several plant species at heights between 0 and 400 cm, and that only camouflage was an important factor in TSD. The estimates were higher during the nestling phase, corroborating our hypothesis. Predation was the main cause of losses, however with rates similar to those observed for species of other orders and other environments. Our results contribute to a better understanding of the evolution of life history of birds inhabiting tropical regions, since the existing pattern is based on data from rain forests. In chapter 3, we estimated detection rates and abundance of C. minuta and C. picui in two different physiognomies. We evaluated the hypothesis that the density is higher in the open physiognomy, that the species are more abundant during the wet season, and that they are able to perform regional movements. For analyzes, we developed Huggins’ closed population models in MARK program. The results corroborate our three hypotheses. The population size suggested greater abundance in savanna shrub and during the wet season. Recoveries of C. minuta in other Caatinga localities, combined with low capture and recapture rates, and low fidelity to the sample areas, indicate that nomadism can be the main strategy adopted by this species to maintain its populations in face of the climatic unpredictability of the Caatinga. The present thesis presents unprecedented results regarding the natural history of birds inhabiting tropical seasonally dry environments. In addition, it contributes to the understanding of the strategies adopted by granivorous species to maintain their populations in periods of severe resource scarcity, which will be much more frequent in a climate change scenario.

8
  • HELOÍSA DANTAS BRUM
  • Ecology and economy of açai (Euterpe precatoria) in riverine communities in Central
    Amazon

  • Advisor : ALEXANDRE FADIGAS DE SOUZA
  • COMMITTEE MEMBERS :
  • ALEXANDRE FADIGAS DE SOUZA
  • EDUARDO MARTINS VENTICINQUE
  • BRÁULIO ALMEIDA SANTOS
  • CRISTINA BALDAUF
  • JOÃO VITOR CAMPOS E SILVA
  • Data: Jul 24, 2019


  • Show Abstract
  • The historical interdependence between human populations and the traditional use of biodiversity and ecosystems shaped the Amazon as one of the most rich and complex social-ecological systems. Amazon forest still facing a huge set of threats through deforestation to cattle ranching, soy production and road paving, besides the several damages on short and long-term of dam’s construction and over-exploration of natural resources. All these threats have a global impact, as innumerous studies already show the key role of the largest world tropical forest for climate regulating. Protected areas are one of the most efficient way to protect biodiversity but the simple creation is not a guarantee of their effectiveness. Conservation is dependent on the integration of ecological and social aspects of stakeholders responsible for use and protection of biodiversity. Nontimber forest resources are an important cultural component of traditional people and can represent a significative source of household income. Specifically, the palm tree açai (Euterpe precatoria, Arecaceae) is the most iconic Amazon plant species with a huge cultural value in Central and Westerns Amazon till Central America. Recently, it is gaining attention of national and international markets because of its nutritious and energetic contents and antioxidant properties. This study was developed to provide information on social and ecological aspects of the use and commercialization of natural resources in riverine communities in Central Amazon, and specifically on açaí palm tree (Euterpe precatoria) in different habitats. We intend this study to be the first step to provide scientific knowledge and support for social organization to assist locals in a larger participation along the supply chain and management decisions, aiming to achieve the goals of the Sustainable Development Reserve.

9
  • JÚLIA TOVAR VERBA
  • Seascape effects on commercially important fish populations

  • Advisor : PRISCILA FABIANA MACEDO LOPES
  • COMMITTEE MEMBERS :
  • ADRIAN ANTONIO GARDA
  • BEATRICE PADOVANI FERREIRA
  • GUILHERME ORTIGARA LONGO
  • PRISCILA FABIANA MACEDO LOPES
  • RICARDO RODRIGUES DA SILVEIRA FILHO
  • Data: Aug 27, 2019


  • Show Abstract
  • Fisheries science is characterized by several knowledge gaps that prevent the development of more sound research for fish stock conservation. Understanding how these stocks are spatially distributed and which genetic and environmental characteristics explain this distribution is crucial for fishery planning. In this thesis we describe conservation status, population genetics structure and connectivity, and effective population size of commercially important marine fish in Brazil. The first chapter presents an analysis of catch data for 132 species for 61 years. The results indicate a complex interaction between climatic and biological factors, besides exploitation type, affecting the species collapsing risk. The second chapter, using COI and CytB mitochondrial markers analysis, we identified the population genetics structure and historical demography for 17 commercially exploited marine fish species. Most species presented a lack of environmental barriers to gene flow along the Brazilian coast. However, population structure of Pomatomus saltatrix and Cynoscion jamaicensis results indicate genetic discontinuity due to temperature changes and isolation by distance, respectively. The goal of the third chapter was to identify effective population size variability for two reef species – Lutjanus jocu and Sparisoma axillare – and test the influence of past climatic variability on population size changes. Sparisoma axillare population expanded until five thousand years ago and is mostly stable until today, with a population expansion justified by increase in suitable habitat. For Lutjanus jocu, results suggest that, after a period of population expansion, is has been stable for the last one million years. Habitat suitability for L. jocu is apparently stricter nowadays than in the past, but this change does not seem related to population size. Distribution range of L. jocu is larger than S. axillare (endemic to Brazil), so it might be less susceptible to regional climatic changes. In the fourth chapter, we identified which seascape characteristics explain genetic connectivity patters of S. axillare, by analyzing samples collected in six sites on the Brazilian coast and in the islands of Fernando de Noronha, Abrolhos and Trindade. The results indicate that only Trindade Island population is genetically distinct. We found that seascape factors, as bathymetry and oceanic currents, can be more important to explain genetic variation than geographical distance. The results of this thesis indicate an important effect of environmental variables, such as temperature, oceanic currents and depth, on the vulnerability, connectivity and population size of marine fish in Brazil. However, we found a low environmental effect on species population structure. Our results can be applied for marine planning in the region.

10
  • RAFAEL DOMINGOS DE OLIVEIRA
  • Experimental gradientes of diversity influencing herbivory and plant-insect interactions in plant communities

  • Advisor : GISLENE MARIA DA SILVA GANADE
  • COMMITTEE MEMBERS :
  • GISLENE MARIA DA SILVA GANADE
  • GUILHERME GERHARDT MAZZOCHINI
  • LEONARDO HENRIQUE TEIXEIRA PINTO
  • MARCIO ZIKAN CARDOSO
  • MARILIA BRUZZI LION
  • Data: Aug 30, 2019


  • Show Abstract
  • There is evidence that biodiversity directly influences or correlates with functions and services offered and regulated by ecosystems. In addition, plant diversity can affect aspects related to higher trophic levels, such as abundance and diversity of insect herbivores, herbivory patterns, and multitrophic interactions between plants, herbivores and their natural enemies. Therefore, this thesis examines how herbivory by insects can be affected by the diversity of plant species, by the diversity of functional characteristics of the plant species, as well as investigates the configuration of the interaction networks between insects and plants. The study was performed in large-scale experiments in the Brazilian Caatinga and in Germany grasslands. In these experiments, plant communities were constructed with different levels of plant diversity. Chapter 1 studies how insect herbivory affects plant mortality and is affected by planting diversity in a Caatinga restoration program in the Brazilian semi-arid region. The results indicate that plant diversity at this early stage of restoration does not affect herbivory rates. It was also verified that the presence of herbivore insects did not jeopardize the initial establishment of plants during the Caatinga restoration, hence, it is not necessary to use any insecticide to combat possible pests that could harm the restoration. Chapter 2 studies the characteristics of the interaction network between insects and plants in the first two years of the Caatinga restoration experiment. The number of links was higher in older communities, as well as they seems more nested compared to the young ones. The presence of highly generalist insect species are evident, and some plant species act as hubs of interaction in the networks. Chapter 3, conducted in Germany, discusses how insect herbivory can be influenced by both the plant diversity and the morpho-functional traits of these plants. A positive relation between plant richness and insect herbivory rates was found. Furthermore, herbivory rates are influenced by seasonality. However, functional diversity and species compositions grouped sorted by different functional traits (species pools) did not affect herbivory.

     

2018
Dissertations
1
  • EWALDO LEITÃO DE OLIVEIRA JÚNIOR
  • Copepods functional traits determine duration of facilitation on filamentous cyanobacteria

  • Advisor : RENATA DE FÁTIMA PANOSSO
  • COMMITTEE MEMBERS :
  • JULIANA DEO DIAS
  • RENATA DE FÁTIMA PANOSSO
  • ROSEMBERG FERNANDES DE MENEZES
  • Data: Feb 16, 2018


  • Show Abstract
  • Top-down regulations in trophic chain depend on herbivore grazing traits and producers edibility. By actively selecting nutritious eukaryotic phytoplankton and rejecting toxic cyanobacteria, grazing copepods may contribute to cyanobacteria blooms dynamics. In tropical environments, for instance, copepods commonly co-occur with cyanobacteria blooms, raising the question whether they can facilitate cyanobacteria dominance. We experimentally tested the effects of two groups of copepods with different feeding modes – calanoid Notodiaptomus iheringi (active filter feeding) and cyclopoid Thermocyclops decipiens (raptorial feeder) – on the competition of an eukaryotic phytoplankton Cryptomonas and the filamentous cyanobacteria Cylindrospermopsis raciborskii. We assessed grazing in 1L batch cultures for seven days, starting with 10-fold initial dominance of Cryptomonas. Copepods demonstrated initial rejection of Cylindrospermopsis filaments, but while cyclopoids slightly increased grazing on cyanobacteria in extended experimental periods, calanoids reversed to clear more particles of cyanobacteria. Despite differences on grazing, both zooplankton shredded cyanobacteria filaments, reducing filament size in ~70%. We also performed experiments testing competition between phytoplankton that showed no interference on each other growth rates, assuring that results from grazing experiment are addressed to zooplankton feeding. Here, we demonstrated that copepod selectively avoidance of filamentous cyanobacteria Cylindrospermopsis is not constant. Copepods were able to decrease overall biomass and shorten filaments of prey. Copepods grazing may not be the most appropriate mechanism to explain filamentous cyanobacteria blooms. While environmental correlations due to long term monitoring are important and may reveal interesting trends, a mechanistic approach to understand trophic dynamics of separate different groups (i.e. copepods and filamentous cyanobacteria) is necessary. This is especially relevant in light of the more intense warmer and eutrophic world that will promote cyanobacteria bloom, and increase complexity of such interactions.

2
  • AUGUSTO CÉSAR DA SILVA
  • Floristic groups and their environmental relations in the Caatinga seasonally dry vegetation, northeastern of South America.

  • Advisor : ALEXANDRE FADIGAS DE SOUZA
  • COMMITTEE MEMBERS :
  • ALEXANDRE FADIGAS DE SOUZA
  • CARLOS ROBERTO SORENSEN DUTRA DA FONSECA
  • MARCELO FREIRE MORO
  • Data: Feb 20, 2018


  • Show Abstract
  • Aim Biogeographical regionalizations are representations of the organization of organisms in the geographical space in function of the various biotic to abiotic factors to past or present. Our aim was to propose a vegetacion bioregionalization of Caatinga based in floristic data, identifying the factors main that determine the grups distribuition patterns.

    Location Caatinga phytogeographical domain

    Methods We compiled 266 floristic inventories that to composse the “Caaporã” database. The floristic inventories were used to build a species-by-site matrix and used unconstrained ordination and clustering techniques to identify the number of floristic groups in Caatinga. We applied an interpolation method to map axes of compositional variation over the whole extent of the Caatinga and then classified the compositional dissimilarity according to the number of floristic groups identified a priori. In addition, we performed a hierarchical analysis (UPGMA) to verify the relationship between the groups. We used multinomial logistic regression models with AIC and wAICc criteria to investigate the influence of contemporary productivity, topographic complexity, historical climate shifts and human footprint in explaining the floristics groups.

    Results We identified a total of 2872 species of plants organized into nine floristic groups, some are distributed latitudinally (North-South), while others are restricted to certain specific regions in the southern and western portions of the domain. The results of the multinomial regression show that the aridity index (AI) individually was the variable that best explains the distribution pattern of the groups. Therefore productivity was the significant model that best describes the distribution pattern of the groups. The models evaluating soil, topography and historical variables were not significant.

    Main Conclusions The distribution pattern of the Caatinga biogeographic groups was shown to be largely determined by aridity. Due to its climatic variability and instability throughout the domain it is possible that many of the floristic groups present in the Caatinga are composed of groups of species from the Atlantic Forest, the Cerrado or even the Amazon. Overall, the regionalization of the Caatinga into floristic groups provides a cohesive spatial representation of the biogeographic distributions in the Caatinga. Therefore, our proposed classification together with the other suggestions contribute to a better understanding of the floristic distribution patterns of the caatinga and the processes that govern these floristic groups.

3
  • ADRIANA ALMEIDA DE LIMA
  • Influence of climate change on the alfa and beta diversity of the Atlantic Forest primates

  • Advisor : MIRIAM PLAZA PINTO
  • COMMITTEE MEMBERS :
  • LEANDRO JERUSALINSKY
  • MIRIAM PLAZA PINTO
  • SIDNEY FEITOSA GOUVEIA
  • Data: Feb 23, 2018


  • Show Abstract
  • Changes in climatic conditions influenced by human activities have an impact on biodiversity. Modifications in species distributions can alter diversity patterns over time and space. The Atlantic Forest is a region of high primate vulnerability due to climate change. We will investigate how these changes, in optimistic and pessimistic scenarios, will influence the patterns of primate diversity in the Atlantic Forest. Specifically: i) where are the largest changes in species richness expected? ii) the spatial pattern of beta diversity will undergo homogenization or heterogenization? and iii) where are the major changes in species composition projected? We generated geographic distributions for species from current climate suitability models. The richest regions in species will be more concentrated on the coast of the biome and the richness will decrease in areas of ecotone. Changes in richness will occur predominantly due to species loss. Spatially, communities will be more heterogeneous in the future, with increased beta diversity. The heterogenization should be driven by the reduction of the area of species geographic distributions. In the future, ecotone regions, especially the central Atlantic Forest and the westernmost region, both in contact with Cerrado, will become more heterogeneous and will undergo great changes in species composition. The changes in the precipitation regime predicted for these areas influence the  primates diversity directly, due to the physiological tolerances of the organisms, and indirectly, through changes in the forest structure and resources availability. The results should be observed with caution, since there are sources of uncertainties in the projections. Nevertheless, we consider that the changes detected are underestimated because the projections were restricted to the known area of the species and the dispersion in the future is extremely compromised by the high loss and fragmentation of habitat in the Atlantic Forest.

4
  • MAURÍCIO DÁLIA NETO
  • Species richness, evolutionary history and functional traits: relationships between the diversity geographic patterns of Caatinga birds.

  • Advisor : MIRIAM PLAZA PINTO
  • COMMITTEE MEMBERS :
  • MIRIAM PLAZA PINTO
  • CARLOS ROBERTO SORENSEN DUTRA DA FONSECA
  • Marcos Figueiredo
  • Data: Feb 26, 2018


  • Show Abstract
  • The biological diversity can be divided into at least three distinct and complementary types, which include taxonomic, phylogenetic, and functional diversity. Understanding how these components vary in space is the key to better understanding the threat to biodiversity.In addition, analyzing communities from a local perspective (alpha component) and between communities (beta component) generate more information on how the various forms of diversity can be distributed geographically. In recent years, the relationship between spatial patterns of diversity has occupied the attention of ecologists, especially to understand how these components change locally and geographically. With this, we aim to describe the geographic patterns of richness, evolutionary history, phylogenetic and functional differences of birds in the Caatinga dry forest, in the alpha and beta components of diversity.We also investigate whether spatial scale and different phylogenetic sources influence the results. For this, we selected 405 bird species from distributions from BirdLife, their phylogenetic information from the online BirdTree database, and the functional data from EltonTrait 1.0. We used measures based on species richness, evolutionary history, phylogenetic and functional mean differences, to represent the alpha component. As well as the turnover of evolutionary species and history and average and functional differences between the eight neighboring communities, to measure beta diversity. Comparing the results of the correlations between the different scales (1, 0.5 and 0.25) and phylogenetic topologies, we identified that they do not interfere in the type of result. Contrary to expectations, species richness does not correlate with other forms of diversity. The phylogenetic mean diversity in the alpha component correlated with evolutionary history (r = 0.5) and with functional mean diversity (r = 0.66). In the beta component, the mean phylogenetic diversity is correlated with the functional mean diversity (r = 0.57), as well as the turnover of species with phylogenetic turnover (r = 0.8). The diversity of birds presents a high heterogeneity in their geographical distribution. Probably, this pattern should be highly influenced by climatic and topographical heterogeneity. In general, our results can create subsidies that support the choice of areas for spatial prioritization for bird conservation in the Caatinga.

5
  • PAULO FERNANDES DA COSTA NETO
  • Patterns of habitat use and co-occurrence of the Herpsilochmus genus in a forest remnant in the northern of Atlantic Forest distribution

  • Advisor : MAURO PICHORIM
  • COMMITTEE MEMBERS :
  • MAURO PICHORIM
  • EDUARDO MARTINS VENTICINQUE
  • RODRIGO LIMA MASSARA
  • Data: Feb 28, 2018


  • Show Abstract
  • The bird distribution in the environment is modulated by habitat complexity and seasonal changes in resource availability, characteristics whose understanding is essential for accurate inferences about how species use the habitat. In addition, interspecific interactions also affect the distribution and the way in which the species use the habitat and may be an important factor to understand the coexistence, especially between congeneric species. Here, we used occupancy models for one and two species to investigate how vegetation structure and interspecific interactions affect patterns of habitat use and co-occurrence in three sympatric species of the genus Herpsilochmus (H. atricapillus, H. pectoralis and H. rufimarginatus). The study was carried out in a forest remnant at the northern portion of the Atlantic Forest distribution (RPPN Mata Estrela), northeastern Brazil. For this, we performed point-count surveys in 80 sample units, in the dry and rainy season, and collected variables related to the vegetation structure. From this we created sets of occupancy and co-occurrence models and selected the best ranked for each species and combination of species. As results of occupancy models we verified that the species H. atricapillus and H. pectoralis had high occupancy rates (Ѱ > 0.89 ± 0.07), whereas H. rufimarginatus had moderate, which was higher in forest areas (Ѱ = 0.47 ± 0.34 - 0.68 ± 0.15). The density of trees was the most important variable in the occupancy of the species, but with positive effect on H. pectoralis and negative effect on H. rufimarginatus. Although the best model for H. atricapillus also includes tree density, the effect of the variable seems uncertain. The detection probabilities ranged from low (p = 0.19 ± 0.03) to moderate (p = 0.59 ± 0.05) between species. The co-occurrence models brought evidence that H. pectoralis is related with a decrease in H. rufimarginatus occupancy, which was stronger in restinga areas, while the detection probabilities were independent for both. In the other side, the presence of H. atricapillus positively affected the occupancy of H. rufimarginatus, mostly, in restinga areas. Finally, the occupancy of H. pectoralis was independent of H. atricapillus, but the detection was negatively affected by the presence of H. atricapillus. Our results indicate that the tree density is the most important factor in the habitat use by the species studied here. In addition, the occupancy pattern of H. pectoralis and H. rufimarginatus could be influenced by competitive interactions, which associated with different micro-habitat preferences may be modulating the coexistence among these species. In contrast, H. rufimarginatus may be benefiting from the presence of H. atricapillus by following mixed flocks, either by increasing foraging efficiency or by protecting themselves against predators, but more studies are needed to understand this pattern of aggregation among species.

6
  • JOÃO LUCAS GOMES DE SOUZA SILVEIRA
  • Environmental inffluence over the cooccurrence patterns of two congeneric bird species in a forest fragment within NE Brazil

  • Advisor : MAURO PICHORIM
  • COMMITTEE MEMBERS :
  • EDUARDO MARTINS VENTICINQUE
  • LEONARDO FERNANDES FRANÇA
  • MAURO PICHORIM
  • Data: Mar 8, 2018


  • Show Abstract
  • One of the main explanations for the high tropical species diversity is the possibility of coexistence between species with similar niche. Coexistence studies investigate how species are organized in time and space, also focusing on the interactions between them and with the environment. Although the interspecific competition seems to explain alone the cooccurrence patterns, environmental characteristics may have the same power of explanation. Therefore, identify which factors influence species coexistence is essential for elucidating the community regulation mechanisms. Creating theoretical models that incorporate species detection and occupancy estimates allows one to simultaneously evaluate multiple hypothesis about the species occurrence patterns. Occupancy estimates have been increasingly used as a tool in modelling species dynamics, also guiding monitoring strategies and management actions. This study focused on two Passeriformes species Conopophaga cearae (Chupa-dente-do-nordeste) e Conopophada melanops (Cuspidor-de-mascara-preta) for a better understanding the patterns of space usage by the ornithofauna at the North-eastern Brazilian Atlantic Forest. Our assessments were conducted at the RPPN Mata Estrela, south coast of RN state, via hearing spots (?), visited over two distinct seasons: a dry one (September, October and November 2016) and a wet one (May, June and July 2017). To clarify the field-collected data, we created and tested static and conditional occupancy models in the program MARK. With the static occupancy models, we observed that the environmental preferences are different between species and the niche plasticity of C. cearae seems to contribute significantly for the species cooccurence. In addition to that, the conditional occupancy modelling pointed that environmental characteristics (both seasonality and habitat structural conditions) are more relevant for the choice of areas by these species than the interaction between them.

7
  • MAIARA MENEZES
  • DYNAMIC OF PICOPLANKTON IN THE WESTERN COAST OF EQUATORIAL ATLANTIC OCEAN

  • Advisor : ANDRE MEGALI AMADO
  • COMMITTEE MEMBERS :
  • ANDRE MEGALI AMADO
  • GUILHERME ORTIGARA LONGO
  • RODOLFO PARANHOS
  • Data: May 4, 2018


  • Show Abstract
  • Most of the ocean biomass is microbial, and picoplankton microorganisms, which consists of small cells (<3 µm), are central players of global nutrient cycle and C production. Heterotrophic bacteria, cyanobacteria (Synechococcus) and autotrophic picoeukaryotes comprise picoplankton and commonly dominate microbial abundance and biomass production in oligotrophic waters of low latitude oceans. Thus, evaluate temporal dynamics of these organisms is crucial for understand microbial stocks and fluxes in equatorial regions. Here, we performed monthly samplings between 2013-2016 at Equatorial Atlantic Microbial Observatory (EAMO) situated on the coast of RN state – Brazil, to evaluate variations in abundance, biomass and activity (bacterial production and respiration) of picoplankton assemblage; and to identify the environmental factors that may regulate it in a scenario of greater environmental stability, where rainfall marks seasonality. Our results revealed that seasonality expressed a weak influence on picoplankton assemblage considering abundance, biomass and metabolic activity, with exception of Synechococcus, which peaked during dry seasons. Heterotrophic bacteria dominated picoplankton during entire study period; and showed higher abundances in July months, as well as picoeukaryotes. Interannual influence related to El Niño (ENSO) event in 2015 was also evidenced for total picoplankton assemblage. Autotrophic picoplankton (Synechococcus + picoeukaryotes) contributed in average for 30% of total picoplankton biomass (in contrast with heterotrophic fraction), and for 58% of total chlorophyll a. Among environmental factors, salinity proved to be the variable that best explained the abundance of picoplankton, with greater abundances during periods of low salinity water. However, weak environmental relationships found may suggest a greater importance of biological interactions (as competition and/or grazing) leading to picoplankton fluctuations throughout the year.

8
  • GIESTA KRISHNA DE SAINT GEORGE
  • Modeling Primate Corridors In The Brazilian Northeast

  • Advisor : ADRIANA MONTEIRO DE ALMEIDA
  • COMMITTEE MEMBERS :
  • ADRIANA MONTEIRO DE ALMEIDA
  • EDUARDO MARTINS VENTICINQUE
  • LEANDRO JERUSALINSKY
  • Data: May 17, 2018


  • Show Abstract
  • Fragmentation and loss of habitat associated with anthropic activities are the most cited causes of loss of biological diversity. The reduction of forest habitats results in the isolation of populations and the greater risk of extinction. Arboreal primates are threatened mainly by fragmentation and loss of habitat. In the present study we approached two species of primates: Callicebus coimbrai (Primates, Pitheciidae) is endemic to the Northeastern Atlantic Forest, while Callicebus barbarabrownae endemic to the Caatinga. Both live in fragmented landscapes with high degree of isolation, with distribution in the states of Sergipe and Bahia, northeastern Brazil. The objective of this work was to identify possible connection routes between forest remnants occupied by the species, as well as to model ecological corridors within previously defined priority areas for the conservation of Callicebus coimbrai (Atlantic Forest) and Callicebus barbarabrownae (Caatinga). Corridors were simulated for 12 priority areas for Atlantic Forest and seven for Caatinga. For this, we used images classified as land use (MapBiomas 2016), on which we generate resistance surfaces. Altogether, we simulated 570 corridors, with 30 replicates for each priority area. A total of 74 fragments were identified for connection in priority areas of C. coimbrai and 36 in priority areas of C. barbarabrownae. The greatest coverage of land use in priority areas in the Atlantic Forest was Agriculture or Pasture (60.37%), while in the Caatinga it was Open Forest (52.16%). The total areas of the Caatinga polygons are larger than those of the Atlantic Forest, as well as the number of fragments. However, the density of fragments was higher in the Atlantic Forest, indicating high fragmentation. Ecological corridors were longer in the Caatinga and had lower costs per meter than in the Atlantic Forest. Landscapes in the Caatinga are more permeable to the crossing of the studied species, in relation to the Atlantic Forest. We recommend conservation actions primarily for the species C. barbarabrownae, which is classified as "critically endangered" from extinction. For Callicebus coimbrai we recommend the implementation of stepping stones to reduce the problems related to the low permeability of the matrix to which it is inserted.

9
  • DANIELE COSME SOARES DE MORAES
  • Population aspects of Xiphopenaeus kroyeri (Heller, 1862) (Crustacea, Decapoda, Penaeidae) on the eastern coast of northeastern Brazil

  • Advisor : FULVIO AURELIO DE MORAIS FREIRE
  • COMMITTEE MEMBERS :
  • FULVIO AURELIO DE MORAIS FREIRE
  • ROSANGELA GONDIM D OLIVEIRA
  • TIEGO LUIZ DE ARAÚJO COSTA
  • Data: Jun 26, 2018


  • Show Abstract
  • Seabob shrimp Xiphopenaeus kroyeri has great economic interest in several regions of the Brazilian coast. Despite its importance, its life history is still poorly understood, making it difficult to assess the impact of fishing and climate change on the natural stocks of this species. In this way, the biology and the population growth and the reproductive biology of the species in Baía Formosa, RN were investigated. Besides the relation of its abundance with environmental factors. The shrimp were captured monthly from March / 2013 to February / 2015, in 6 sampling points. The individuals were measured, evaluated for sex and the stage of gonadal development. The environmental factors were obtained using a multiparameter probe, in addition to collecting pluviometric data and sedimentological material. The intra-population groups presented negative correlation with the hydrological variables of temperature and background salinity, water transparency and depth, while the young ones presented a lower degree of relation with the environmental factors. There was significant influence of background temperature, presence of algae and water transparency, with the total abundance of shrimp. Females presented larger sizes than males. Reproduction of the continuous type was observed, with higher reproductive peaks at the beginning of each year. The average length of the first gonadal maturation was 13.6 mm and 14.2 mm for males and females, respectively. There was an inversely proportional relation between the total rainfall and the percentage of reproductive females. Growth parameters showed larger females and showed lower growth coefficient (k), resulting in a longer longevity than males.

10
  • POLIANA MARIA TRINDADE ALVES MORAIS
  • Circadian rhythm of the flowering of Melocactus zehntneri: Who are your pontential visitors and pollinators?

  • Advisor : EDUARDO MARTINS VENTICINQUE
  • COMMITTEE MEMBERS :
  • ALICE DE MORAES CALVENTE
  • EDUARDO MARTINS VENTICINQUE
  • JOSÉ EDUARDO ZAIA
  • Data: Jul 27, 2018


  • Show Abstract
  • The resources in the Caatinga vary with the seasonality of the region and are less abundant in the dry season. In this period few plants are in the flouring period, among them are some Cactaceae, there are few resources for the nectarívoros. For this reason, opportunistic pollinators can visit them and / or steal the nectar. The work will describe the circadian cycle, the nectar production and pattern of secretion, consumption and visitation in Melocactus zehntneri, seeking possible explanations about the interactions between this cactus and bats (Glossophaga soricina, Lionycteris spurelli, Lonchophylla sp. and Xeronycteris vieirai) in the Caatinga of Lajes do Cabugi / RN. Recently, a parallel study has reported that these bats are visiting the cactus because large amount of pollen of the species was found in their hairs or feces. But their flowers do not indicate signs of chiropterophily, therefore data were collected in the field and an experiment was carried out to investigate the existence of floral rewards and responses, in the circadian cycle and in the pattern of nectar secretion, related to this interaction. The volume and concentration of sugar in the nectar decreased after 5:30 pm, but it continues with quality to compensate nocturnal pollinators that begin to forage at that time, such as small bats that living in Caatinga. The hummingbirds are pollinators more efficient of M. zehntneri, and probably they’re sharing the nectar with other floral visitors, including the bats of the region. There is a change in the pattern of nectar secretion before and after at 17:30 pm, which may be associated to the same floral visitors of this plant. This fact may increase the genetic variability in the population of the cactus, since it would also benefit other floral visitors besides the hummingbird that shows a very territorialist behavior. In addition, bats may be using the nectar of this plant as an alternative source of energy in the dry period of the Caatinga, because the resources are scarcer.

11
  • CLETO JOSÉ FREIRE COSTA JUNIOR
  • Effects precipitation reduction on the benthic macroinvertebrate communities of the Brazilian semiarid region.

  • Advisor : JOSE LUIZ DE ATTAYDE
  • COMMITTEE MEMBERS :
  • JOSE LUIZ DE ATTAYDE
  • JULIANA DEO DIAS
  • JOSELINE MOLOZZI
  • Data: Aug 31, 2018


  • Show Abstract
  • The global warming expected consequences for the Brazilian semi-arid region are increased evapotranspiration and reduced precipitation, increasing the hydric deficit and prolonging drought periods. This study hypothesizes that the increase in water deficit, increases the trophic state of semi-arid reservoirs and accordingly reducing the alpha and beta diversity of benthic macroinvertebrates and increasing the susceptibility of lentic aquatic ecosystems to the elevation of trophic state. Eutrophication coupled with a negative water balance driven by climate change tends to promote cyanobacteria blooms, increase salt concentrations and the reduction of oxygen in the water column, which may reduce the complexity of lakes and benthic communities, as this phenomenon acts as an environmental filter selecting species more apt to colonize these environments.To test our hypothesis, we compared the benthic macroinvertebrate communities between two sets of reservoirs located in two neighbouring sub-basins of the Brazilian semi-arid region with contrasting precipitation regimes. The two sets of reservoirs were compared between two periods (dry and extremely dry) to evaluate the effect of drought intensity on benthic macroinvertebrates alpha and beta diversities. The results show that drought intensification increases reservoirs trophic state, especially in the sub-basin with lower annual mean precipitation. However, Contrary to what was expected for the driest basin where the reservoirs presented worse water quality there was increase in benthic macroinvertebrates beta diversity, due greater environmental heterogeneity. Deterministic mechanisms may have been responsible structuring the communities in our study. These results imply understanding the structure of communities in  climate change events of semi-arid regions.

Thesis
1
  • MARIA CLARA BEZERRA TENÓRIO CAVALCANTI
  • Rural livelihoods, poverty and conservation opportunities: understanding the social-ecological resilience in semi-arid regions

  • Advisor : PRISCILA FABIANA MACEDO LOPES
  • COMMITTEE MEMBERS :
  • PRISCILA FABIANA MACEDO LOPES
  • ADRIANA PELLEGRINI MANHÃES
  • CRISTINA BALDAUF
  • FELIPE SILVA FERREIRA
  • JOÃO VITOR CAMPOS E SILVA
  • Data: Feb 16, 2018


  • Show Abstract
  • To date forests remain a source of several goods and services for human groups all over the globe. Dryland forests, for instance, play a crucial role in promoting ecological, social and economic balance, supporting people’s livelihoods. Nevertheless, dryland regions have been imperiled by ineffective environmental policy, droughts that are increasingly more intense and sequential, and adverse human activities, such as intensive land use for agriculture and pasture, rapid urbanization, and population growth. Also, human populations living in dry landscapes are often some of the poorest and most vulnerable in the world. Poverty is one of the aspects that lead people to overexploit natural resources to supply their needs, accelerating environmental degradation. This situation claims for effective policies to promote social equality and biodiversity conservation, which could be facilitated through an integrated understanding of: (1) the conditions that drive people to use and depend on local natural resources; (2) the importance of the environment to supply subsistence and financial needs for the poor; and (3) how vulnerable people would respond to strategies to promote local biodiversity conservation that limit the access to the natural resources they depend upon. This research approaches these three points, each one corresponding to a different chapter, with the overall goal of achieving a better understanding of the social, economic, and ecological dimensions of the resilience of social-ecological systems in semi-arid regions. The study was conducted in the Caatinga, a biodiversity rich biome that lies in the northeast portion of Brazil and encompasses the highest rates of poverty in the country. We used semi-structured questionnaires to interview 254 respondents living in 21 rural communities, spread throughout five distinct previously selected polygons in the state of Rio Grande do Norte. In the first chapter, we found that some of the rural households’ socioeconomic characteristics, together with urban insertion conditions that rural communities are submitted to, played a part in driving the frequency of use of natural resources in a local context. Cultural habits may explain why some resources are continuously used regardless of differences in income or of urban influences amongst the respondents. In the second chapter, we estimated that the economic value of semi-arid natural resources exceeded US$ 40,000.00 and we verified that these resources accounted primarily for the household’s subsistence income (23.5% of the total income). We also noticed that forest environmental income is higher for wealthier households what may result from the use of high economically valued products, such as timber for construction and game meat. Finally, in the third chapter we found that people who felt that an eventual prohibition to access the resources would harm their families tended to accept less restrictive conservation scenarios, in opposition to those with a higher level of formal education. Thus, we should direct environmental policies to support especially those people that depend the most on local resources in order to enhance their adaptation process to deal with the impacts of promoting conservation efforts. By doing so, the resilience of this social-ecological system could be improved.

2
  • JANAINA FREITAS CALADO
  • Impacts of recreational dive in Brazilian reefs

  • Advisor : LIANA DE FIGUEIREDO MENDES
  • COMMITTEE MEMBERS :
  • ALEXANDRE DE GUSMÃO PEDRINI
  • GUILHERME ORTIGARA LONGO
  • JOSE GARCIA JUNIOR
  • LIANA DE FIGUEIREDO MENDES
  • PRISCILA FABIANA MACEDO LOPES
  • Data: Feb 26, 2018


  • Show Abstract
  • Recreational diving is a touristic activity fastest growing in the world, generating employment, income and contributing to the visibility of the importance of the conservation of the reef environments. Despite the socioeconomic advantages, when performed without control, recreational diving can cause negative impacts to the reef ecosystem. Several studies on coral reefs in the world have characterized these impacts by proposing management strategies and biological indicators for monitoring. The peculiarities of Brazilian reefs, with low coral cover and high seaweed and sponge cover, make it necessary to identify and define proper management strategies for this type of use. The present study aims to evaluate the impact of recreational diving causes in a Brazilian Marine Protected Area (MPA). The first chapter presents the survey of the main tourist destinations of recreational diving in Brazil, evidencing their similarities and the current state of research in which they are, regarding the impacts of recreational diving. The results indicate the growth of recreational diving in Brazil and its potential as a promoter of the conservation of reef environments. In the second chapter, it was characterized the behavior of recreational divers in an MPA in the brazilian northeast, quantifying the frequency of touches on the reef substrate related to the profile of the diver and characteristics of the type of diving performed. The average frequency of touches (FT) observed was significantly lower in the studied reef when compared to other studies on coral reefs in the Caribbean, Mediterranean and Australia. The variables that influenced the FT were: type of diving (scuba > snorkel), sex (men > women) and in the age group (above 50 years, higher than in the other age groups). The discussion in this chapter approaches how the physical characteristics of the place of study may have influenced the reduction of FT, as well as the posture of tourism professionals. The third chapter is under construction and deals with the impacts of recreational diving on the ichthyofauna and the benthic reef community, proposing appropriate indicators to the characteristics of Brazilian reefs. In this chapter, it is possible to observe changes in the richness, composition, biomass and trophic classes of fish, and analyze changes in substrate cover, biologic vulnerability, invertebrates’ megafauna and coral health in high and low use areas over two years. The fourth and final chapter approaches with the use of alternative methodologies in an Environmental Education (EE) project aimed at its effectiveness, focusing on the impacts that tourism promotes. The results indicate that the combination of scientific knowledge, local knowledge, use of media and visits to non-formal environment are fundamental to the effectiveness of an EE project. This thesis presents pioneers data on the impacts that recreational diving generates in Brazilian reef environments, effectively contributing to the management and development of sustainable tourism in marine protected areas.

     

3
  • MONALISA RODRIGUES OLIVEIRA DA SILVA
  • Coastal social-ecological system: an integrative analysis to fishery conservation in Brazil

  • Advisor : PRISCILA FABIANA MACEDO LOPES
  • COMMITTEE MEMBERS :
  • ADRIANA ROSA CARVALHO
  • BEATRICE PADOVANI FERREIRA
  • GUILHERME ORTIGARA LONGO
  • MARIA GRAZZIA PENNINO
  • PRISCILA FABIANA MACEDO LOPES
  • RONALDO ANGELINI
  • Data: Apr 4, 2018


  • Show Abstract
  • Promoting fisheries conservation in Brazil is important given its dense hydrographic network and its huge coastline, marked by a strong dependence on this ecosystem service by the society. However, it is known that the majority of fish stocks are overexploited worldwide, risking the sustainability of fisheries and the livelihoods of human communities that depend on these resources. In this context, fishing management strategies are important for maintaining the stocks and sustainability of these communities. However, if poorly planned, these strategies can interfere in the resilience of socioecological systems and in the provision of ecosystem services. In this study, socioeconomic, political and ecological relations of the marine socioecological system were investigated using an integrative analysis along the Brazilian coast. Information on the regional fishing dynamics, socioeconomic aspects, geographic and ecological variables were collected from online databases. Questionnaires were also used to collect data directly with fishers. In the first chapter, the current situation of fish stocks of some endangered species was analyzed, as well as the changes of these stocks and the economic gains from fishing under different conservation scenarios. In the second chapter, a vulnerability index was created to access the socioecological vulnerability of coastal states. Finally, in the third chapter, fishers’ compliance behavior and its consequences to the sustainability of fisheries were analyzed in fishing communities in the Rio Grande do Norte state. Our findings can be used in the zoning and selection of areas for conservation actions, and in the implementation of new management strategies or evaluation of those already in place. It is expected that this study will contribute to the maintenance of fishing activities, the protection of fishing resources and the sustainability of the fishing communities.

4
  • PABLO LÚCIO RUBIM COSTA DOS SANTOS
  • Effects of omnivorous planktivorous and benthivorous fish in tropical lakes

  • Advisor : JOSE LUIZ DE ATTAYDE
  • COMMITTEE MEMBERS :
  • GUSTAVO HENRIQUE GONZAGA DA SILVA
  • JOSE LUIZ DE ATTAYDE
  • JULIANA DEO DIAS
  • RODRIGO FERNANDES
  • VANESSA BECKER
  • Data: Apr 27, 2018


  • Show Abstract
  • Plankivorous and bentivorous fish are key drivers of phytoplankton biomass and water turbidity. Therefore, restoration techniques for eutrophic lakes based on the selective removal of these fish (or biomanipulation) have been developed and used with relative success in temperate lakes. The viability of these techniques in tropical lakes, however, is uncertain due to differences in fish communities in tropical and temperate lakes. For instance, in warmer lakes fish assemblages shows higher degree of omnivory. To evaluate the effects of omnivorous fish on phytoplanktonic biomass and turbidity in tropical lakes and their implications for biomanipulation, mesocosms experiments were conducted with two omnivorous species. Nile tilapia (Oreochromis niloticus Linnaeus 1758) is an exotic planktonic species that is able to filter-feeds on suspended particles, including phytoplankton and zooplankton. The curimatã (Prochilodus brevis Steindachner 1875) is a native bentivorous species that feeds on algae, detritus and microinvertebrates. The results of the experiments are presented in three chapters. The first chapter deals with the mechanisms by which each species affects planktonic production and water turbidity. The second chapter deals with the consequences of the interaction between the two species for turbidity and phytoplankton biomass. The density dependent effects of curimatã on aquatic communities and water quality are analyzed in the third chapter. The results suggest that, through different mechanisms, the two species contribute to phytoplankton increase and water turbidity and that theres no synergistic interaction between the effects of the two species. It is possible to conclude, based on the results, that the removal of tilapia and curimatã can be a viable alternative of biomanipulation in tropical environments.

5
  • CARLOS ADRIÁN GARCÍA RODRÍGUEZ
  • Ecological drivers of macro and microevolutionary processes in complex regions

  • Advisor : GABRIEL CORREA COSTA
  • COMMITTEE MEMBERS :
  • ADRIAN ANTONIO GARDA
  • DIOGO BORGES PROVETE
  • FABRICIO VILLALOBOS
  • GABRIEL CORREA COSTA
  • SERGIO MAIA QUEIROZ LIMA
  • Data: May 10, 2018


  • Show Abstract
  • Mountain areas around the world cover less than 15% of global land surface; nevertheless, they concentrate around 90% of the hotspots of species diversity and 40% of the hotspots of endemism. Available evidence suggest that ecological factors such as landscape features (i.e topographic complexity, climatic heterogeneity and their historical dynamics) of mountains may play an important role in the evolution and maintenance of rich biotas at such regions.  In my dissertation I aim to evaluate the role of such factors in both macro (i.e global speciation patterns) and microevolutionary (i.e intra-specific genetic and trait divergence) processes using amphibians as study system. In the first chapter, we tested in a global scale the Montane Pumps hypothesis, which proposes that speciation rates are faster in mountains explaining higher diversities in those regions. To this end we used a near complete Amphibian phylogeny containing 7238 species (>90% of the group’s extant diversity) and conducted a Bayesian Analysis in Macroevolutionary Admixtures (BAMM) to estimate speciation rates. Then we combined this information with available range maps to explore Amphibian geographic patterns of speciation and evaluated its association with complex terrains (mountains) by estimating a global index of topographic complexity. We found that globally, speciation rates are faster in regions of high topographic complexity independently of latitude. We repeated our analyses using the Wallace’s Zoogeographic regions, taking into account regional independent evolutionary histories, and found the same pattern in eight out of the total 11 zoogeographical realms. In a second chapter, we assess the relative role of different components of the landscape in promoting lineage diversification across the roughed topography of Isthmian Central America (Costa Rica & Panama), a geologically young but highly biodiverse region. Here we use available mitochondrial DNA to estimate genetic divergence within 10 amphibian species (8 anurans and 2 salamanders) with different biologies that co-occur in the region. Then, we use a Multiple Matrix of Regression with Randomization to assess the relative role of isolation by distance, by environment and by resistance (topography, current climate, and LGM paleoclimate) in shaping thegeographic patterns of genetic structuration within each species. So far, we have not found a general force that explains genetic divergence in all studied species. Instead, we have found idiosyncratic responses that may reflect specific aspects of their life histories, such as dispersal capabilities, range size or reproductive potential. In the third chapter, we test how climatic and topographic barriers may influence variation in an important behavioral trait such as are advertisement calls. In anurans, such calls has species-specific features that play an important role in recognition. Then, variation in spectro-temporal features between populations has been proposed as a mechanism of reproductive isolation that may promote speciation in the long term. For this chapter I recorded advertisement calls of 170 males from 2 species of Diasporus frogs distributed in Costa Rica. I made recordings at 21 sites in all the country ranging from sea level to 2800 meters elevation. We use such information we conduct bioacoustics analyses to first document geographic variation and then test if the geographic distance, physical or ecological barriers between populations, or adaptation to local conditions could shape such patterns. To this end, we incorporate spatial analyses (niche models, terrain roughness estimations and circuit theory) to generate levels of population isolation and apply Generalized Dissimilarity Matrix test to address this question. In both species, I found high levels of acoustic variation and among population isolation derived by the tested factors. However, only topography significantly explained acoustic divergence in D. diastema while climatic dissimilarity and geographic distance are only marginally associated with the patters of acoustic variation in D. hylaeformis. In conclusion, other forces operating independently in the local scale -such as sexual selection, character displacement or genetic drift- may be more determinant in the evolution of acoustic signals in these species.

6
  • JOSÉ LUIZ ALVES SILVA
  • UNDERSTANDING PLANT FUNCTIONING, COMMUNITY ORGANIZATION, AND EFFECTS OF PLANTS ON THE RESTINGA ECOSYSTEM

  • Advisor : ALEXANDRE FADIGAS DE SOUZA
  • COMMITTEE MEMBERS :
  • ALEXANDRE FADIGAS DE SOUZA
  • ADRIANO CALIMAN FERREIRA DA SILVA
  • EDSON APARECIDO VIEIRA FILHO
  • BERNARDO MONTEIRO FLORES
  • MARIANA BENDER GOMES
  • Data: Jul 9, 2018


  • Show Abstract
  • Plant form and function depend on internal stimuli (genetics and phenotypic plasticity) as well as external stimuli (environment) that act in the leaf, stem, and root. Water shortages and poor-nutritional sandy soils in the coastal region are cited as the main external stimuli to plants in the Restinga ecosystem. It has been proposed that coordination among plant organs tends to increase with environmental harshness due to a decrease in the viable niche space and an increase in the costs to adopt ecological strategies out of this viable niche space. The first thesis chapter aimed to test this hypothesis in the Restinga. Pairwise correlations of 21 functional traits of 21 species revealed that the stem had greater internal coordination than the leaf organ. In addition, a multivariate analysis showed high independence between stem and leaves, suggesting that stressful environments do not necessarily have plants with high coordination between organs. These results were published in Ecology and Evolution. Functional coordination is directly linked to the success of plant occurrence and may interfere in the community organization. It is still not clear whether weak neutral effects can influence the distribution of functional traits, even though the community shows random patterns of compositional and phylogenetic structure. We address this question in the second thesis chapter. Functional variation in the community resulted from phenotypic responses of all species and individuals rather than particular sets of species or individuals, indicating environmental responses, but not strong patterns in the spatial distribution of traits. In this regard, we accept that the Restinga in the Northeastern South America is influenced by weak neutral effects. We concluded that occurrence and phylogenetic analyses may be insufficient for a complete understanding of the community and should be complemented with functional analyses. The manuscript was submitted to the Journal of Vegetation Science. A weak environmental response may result from low niche partitioning among species, which has been described as the main mechanism underlying the relationships between biodiversity and ecosystem processes. The third chapter assessed the extent to which biodiversity and the environment influence annual litter production, as well as the combined role of rare to abundant species. A path analysis showed that the canopy cover had the greatest influence on production, followed by species richness. Environmental factors had only indirect effects. In addition, the combined contribution of several rare species was lower than the contribution of a few common species. These results suggest that diversity is important not only in short-term and small-scale experiments in the temperate region but also in the plot-scale of tropical forests, mainly through the role played by common species. As a general conclusion, Restinga ecosystem has patterns that deviate from the ones expected in the literature, which highlights the relevance of its biodiversity

7
  • GUSTAVO BRANT DE CARVALHO PATERNO
  • Sex, herbivores and flower evolution

  • Advisor : CARLOS ROBERTO SORENSEN DUTRA DA FONSECA
  • COMMITTEE MEMBERS :
  • CARLOS ROBERTO SORENSEN DUTRA DA FONSECA
  • HARRY OLDE VENTERINK
  • JOHANNES KOLLMANN
  • MARK WESTOBY
  • VANESSA GRAZIELE STAGGEMEIER
  • Data: Jul 30, 2018


  • Show Abstract
  • Parasites represent a strong evolutionary force driving the evolution and maintenance of sex in different organisms. Species with a higher range of parasites should invest more in outcrossing and show more developed secondary sexual characters. In the last decades, many studies found support for this theory in different groups of animals. Nonetheless, a more general test of this theory to plants still poorly explored. Angiosperms show the most diverse range of reproductive strategies among organisms, representing an interesting model for the study of evolutionary forces shaping reproductive strategies. Sexual reproduction in angiosperms happens in flowers which can be divided into four basic components: androecium (male function); gynoecium (female function); corolla (pollinators attraction) and calyx (ovary defense). Surprisingly, comparative studies evaluating resource partition between these flower components remain overlooked. The study of flower allometry in a global scale offer great potential to unveil new macro-evolutionary patterns in plant sex strategy. This thesis is organized in four chapters that investigate patterns of sex allocation in angiosperms and the role of herbivores in the evolution of flower sexual strategies. In the first chapter, flower biomass data was collected across four continents (South America, North America, Europe and Oceania) to test the existence of a general allometric pattern in flower sex allocation of Angiosperms. It was shown that resource allocation to flowers follow a general allometric rule in which species with large flowers invest more in the male and petals components. In the second chapter, I tested the hypothesis that a higher pressure of herbivores at the evolutionary scale favors the evolution of reproductive strategies with higher investment in outcrossing. These results provide strong evidence that the parasite-mediated sex evolution theory (Red Queen Hypothesis) also applies to the plant kingdom. In the third chapter, It was estimated the stoichiometric cost of flowers and leaves for 56 Angiosperm species from the european flora. Its demonstrated that flowers are costly structures, representing a honest signal of quality in the competition for pollinators (Zahavi’s handicap). Flowers are phosphorus rich organs and have a distinct stoichiometric signature showing much higher P:C and P:N ratios than leaves. In the fourth chapter, I present the sensiPhy software which was developed (R package) to perform sensitivity analyses considering multiple types of uncertainties in phylogenetic comparative methods (phylogenetic, intra-specific and sampling uncertainty). With this thesis, I expect to contribute with a more solid and general understanding of the factors driving the evolution of plant sexual strategies at the macroevolutionary scale.

8
  • EDUARDO MATHEUS VON MÜHLEN
  • The Effect of Flood Pulse in Felids Habitat Use in the Amazon Forest

  • Advisor : EDUARDO MARTINS VENTICINQUE
  • COMMITTEE MEMBERS :
  • EDUARDO MARTINS VENTICINQUE
  • CARLOS ROBERTO SORENSEN DUTRA DA FONSECA
  • MAURO PICHORIM
  • JOÃO VITOR CAMPOS E SILVA
  • Wilson R. Spironello
  • Data: Jul 31, 2018


  • Show Abstract
  • A Amazônia é composta em grande parte por florestas que nunca (ou muito raramente) são submetidas ao alagamento sazonal causado pelo pulso de inundação. Entretanto, uma grande parcela do Bioma é formada por áreas que são geralmente submetidas ao alagamento todos os anos no período da cheia dos rios. As florestas alagadas são reconhecidas como uma importante fonte de recursos alimentares para animais das florestas de terra firme adjacentes e estudos recentes demonstram que utilizadas por diversas espécies de mamíferos que buscam diferentes recursos quando as águas estão baixas. Neste sentido, o objetivo principal deste estudo é a identificação de como o pulso de inundação altera a forma de uso dos habitats de várzea e terra firme pela comunidade de felinos e demais mamíferos terrestres de médio e grande porte na Amazônia, além de discutir a importância das áreas de várzea para estas espécies. Complementarmente, discutimos o efeito das populações humanas na ocorrência de felinos em uma área de terra firme da Amazônia. Para isso, utilizamos em todos os capítulos a técnica de armadilhamento fotográfico, em diferentes áreas da bacia do Rio Purus, localizado no Estado do Amazonas, Brasil. No primeiro capítulo deste estudo, realizado em três Terras Indígenas Paumari, localizadas no trecho médio da Bacia do Rio Purus, testamos hipóteses relacionadas ao pulso versushabitat para três níveis: a comunidade de mamíferos de médio e grande porte em geral, três grupos funcionais (Carnívoros, Herbívoros e Edentados) e as espécies separadamente. Desta forma, foi possível compreender as especificidades das respostas dos grupos funcionais e espécies ao pulso de inundação. Aplicamos uma análise de ordenação NMDS sobre uma matriz de dissimilaridade de Bray-Curtis para toda a comunidade e para os diferentes grupos. Para apoiar a interpretação das ordenações, calculamos a dissimilaridade entre os Habitats a partir da técnica de SIMPER (Similarity Percentages) utilizando a distância de Bray-Curtis, que foi a mesma utilizada na ordenação NMDS. Agrupamos cinco modelos como fatores de pressão ambiental que representam fatores moduladores de resposta da comunidade, dos grupos e das espécies (Cota, Habitat, Cota:Habitat, Cota:Habitat:Fase e Nulo). A comparação e seleção dos modelos foi realizada por meio do Critério de Informação de Akaike. Neste estudo, registramos 6574 ocorrências de mamíferos, sendo 5177 (média = 0.573 registros/noite câmera) na Terra Firme e 1577 (média = 0.313 registros/noite câmera) na Várzea. No geral, a maioria das espécies apresentou mais ocorrência em Terra Firme do que em Várzea. O habitat foi o termo com maior importância para todos os grupos, no entanto, houve grande variação entre espécies que apresentaram respostas completamente diferentes em relação ao habitat. Esse padrão geral indica que, mesmo parcialmente, a exploração dos recursos temporariamente disponíveis na floresta alagada na fase terrestre afeta a distribuição e a abundância dos mamíferos nestas regiões. Para várias espécies, identificou-se uma diminuição do número de registros na Terra firme quando a Várzea está disponível. Conforme esperado, estes resultados indicam que a mastofauna utiliza a várzea quando disponível e que a composição de espécies pode variar ao longo do nível do rio. No segundo capítulo, procuramos entender como ocorre o uso do habitat por de felinos Amazônicos nos mesmos tipos de habitat do Bioma (Várzea e Terra Firme), quando a) ambos estão disponíveis ao forrageio, e b) como isto pode estar associado às flutuações na ocupação da terra firme durante as diferentes fases do ciclo hidrológico. Este estudo foi realizado na Reservas de Desenvolvimento Sustentável Piagaçu-Purus (RDSPP) e Reserva Biológica de Abufari (Rebio Abufari), pertencentes ao mosaico de Áreas Protegidas do 

    baixo Rio Purus. Utilizamos 120 armadilhas fotográficas distribuídas em seis blocos de 20 câmeras cada, em áreas de terras firmes contíguas a áreas de várzea, totalizando 648 km2 de amostragem geral. As câmeras permaneceram ativas durante 483 dias contínos em áreas de terra firme e por um período de 162 dias nos ambientes sujeitos a alagação sazonal (várzeas), durante a época seca, quando o habitat fica disponível para forrageio dos felinos. Estimamos a ocupação de grandes felinos na paisagem de duas formas, sendo a) entre os diferentes habitats (várzea e terra firme) e b) entre diferentes fases do ciclo nos habitats de terra firme, visando detectar mudanças ao longo do ciclo, nas mesmas localidades, que pudessem indicar uma movimentação destas espécies para outras áreas. Para ambas as questões, utilizamos modelos hierárquicos baseados em máxima verossimilhança que lidam explicitamente com o problema das detecções imperfeitas.  Nosso esforço total de amostragem foi de 30174 dias-câmera, caracterizando o maior esforço de amostragem contínuo com armadilhas fotográficas para a Amazônia brasileira. Obtivemos 624 registros independentes das cinco espécies de felinos que ocorrem na Amazônia. Nossos dados demonstraram que as espécies utilizam estes habitats de forma distinta. Para onça-pintada e gato-maracajá, a ocupação no período de seca foi maior na várzea do que na terra firme. O oposto foi registrado para onça-parda e jaguatirica, que apresentaram maior ocupação na terra firme. Em relação as fases do ciclo, na terra firme, para onça-pintada, jaguatirica e gato-maracajá, a probabilidade de ocupação na terra firme foi diretamente proporcional ao nível do rio, onde quanto maior a cota (mais elevado o nível), maior a probabilidade de ocupação, que vai decrescendo conforme a baixada da água. Somente as onças-pardas não obedeceram este padrão, apresentando uma probabilidade de ocupação maior durante o período intermediário. Isso demonstra a grande importância das áreas de várzeas para a manutenção destas espécies ao longo do ciclo de vida. No terceiro capítulo, avaliamos o efeito da pressão antrópica e de variáveis de paisagem na ocupação de felinos em uma reserva de uso sustentável na Amazônia central. Nosso esforço total de amostragem (número de dias em que as câmeras permaneceram em funcionamento) foi de 2653 dias-câmera (x =53 + 24.41). Obtivemos 79 registros independentes de quatro das cinco espécies de felinos Amazônicos. Dentre as variáveis testadas para explicar as probabilidades de detecção e ocupação de felinos, a importância de cada uma foi completamente distinta para cada espécie, evidenciando que mesmo espécies de porte e hábitos semelhantes, não encontramos um fator principal dentre os testados que determinasse como as espécies utilizam o ambiente. Nossos resultados demonstram, ao contrário do esperado, que comunidades humanas não afetaram negativamente a probabilidade de ocupação da onça-pintada e da onça-parda. Apenas para jaguatirica, houve uma relação positiva entre a distância dos assentamentos humanos e a sua probabilidade de ocupação. Embora registros de abate de felinos sejam comuns na literatura, nossos resultados demonstram que essa interação conflituosa não afeta a ocorrência dos mesmos em áreas próximas às comunidades humanas residentes em áreas protegidas de uso sustentável na Amazônia.

     

9
  • DHALTON LUIZ TOSETTO VENTURA
  • Water quality and temporal dynamics of the phytoplankton biomass in man-made lakes of the Brazilian semiarid region: an optical approach

  • Advisor : JOSE LUIZ DE ATTAYDE
  • COMMITTEE MEMBERS :
  • JEAN-MICHEL MARTINEZ
  • JOSE LUIZ DE ATTAYDE
  • RENATA DE FÁTIMA PANOSSO
  • THIAGO SANNA FREIRE SILVA
  • VENERANDO EUSTAQUIO AMARO
  • Data: Dec 21, 2018


  • Show Abstract
  • All over the world, scientists, managers and policy-makers have been challenged by several ecological and economic issues caused by the artificial eutrophication of lakes, whose most visible effect is the excessive phytoplankton biomass, commonly represented by the chlorophyll a concentration (chla). While nutrients play a primary role in the temporal dynamics of the phytoplankton biomass, the lakes’ hydraulic regime can exert an external control over such dynamics. In this study, we assessed the influence of the hydraulic regime on the temporal dynamics of the phytoplankton biomass in man-made lakes of the Brazilian semiarid region. Lakes are a crucial source of water resources for human consumption and irrigation in that region, but they are frequently affected by eutrophication and lack an adequate limnological monitoring. To overcome this data deficiency, we assessed the relationships among water quality and optical properties in 13 lakes of the study region, validated an algorithm for estimating chla from images of the MODIS orbital sensor, and generated a 15-year time series for the three largest study lakes: Orós (OROS), Castanhão (CAST) and Eng. Armando Ribeiro Gonçalves (EARG). Because lakes in the Brazilian semiarid region are subject to a seasonally marked hydraulic regime, we hypothesized that it would be reflected on the temporal variation of chla. The comparison between the time series of chla and lakes’ volume supported such hypothesis. The concentrations steeply dropped with intense rainfall-driven water renewal and kept high during the dry periods. The intense rainfall of 2004 abruptly reduced the phytoplankton biomass in EARG and OROS lakes and, for the latter, its effects even extended to the subsequent years. Our results encourage the exploration of the MODIS archived imagery for further studying the temporal dynamics of the phytoplankton in natural and man-made lakes, at both seasonal and interannual scales.

2017
Dissertations
1
  • EMANUEL MASIERO DA FONSECA
  • Phylogeography, evolutionary hotspots and conservation throughout South American open vegetation formations

  • Advisor : ADRIAN ANTONIO GARDA
  • COMMITTEE MEMBERS :
  • ADRIAN ANTONIO GARDA
  • HENRIQUE BATALHA FILHO
  • SERGIO MAIA QUEIROZ LIMA
  • Data: Feb 16, 2017


  • Show Abstract
  • One of the main goals of biogeography is to unveil the processes and mechanisms involved on the generation and maintenance of biodiversity over time and space. Accessing species’ genetic information, coupled with conceptual, methodological, and computational advances have revolutionized the comprehension of evolutionary process. These advances have enabled reconstructing the evolutionary history of species and testing diversification hypotheses (e.g. refugee, physical barriers, diversification time) in a refinement level that once was unfeasible. The diagonal of open formations stretches from northeast to southwest South America, encompassing three biomes: Caatinga, Cerrado, and Chaco. Historically considered species-poor biomes with no evolutionary identity, these regions have witnessed a change in paradigm due to increase of research and, currently, are recognized as holding high levels of richness, endemism, and unique evolutionary histories. However, tempo and mode of fauna diversification throughout this region are still poorly known and the debate remains largely open. This dissertation is composed of two chapters. (i) In the first one, we used a phylogeography approach to test the effects of historical events on the diversification throughout the diagonal of open formations using the lizard Polychrus acutirostris as study model. In order to reach this goal, we infer population structure, phylogenetic relationships between lineages, intraspecific genetic diversity, migration patterns, demography and the spatio-temporal diffusion history. Finally, we tested 12 diversification scenarios using approximate Bayesian computation (ABC). We recovered three non-overlapping lineages that are spatially structured in the Caatinga, northeastern Cerrado, and southwestern Cerrado. Diversification among lineages took place during the Neogene and was associated to a complex scenario involving simultaneous divergence, early stages of diffusion, symmetrical pattern of migration among neighbor lineages, distinct effects of physical and environmental barriers. (ii) The second chapter aimed to identify areas in the Caatinga biome where the genetic diversity is spatially restricted (Evolutionary Hotspots) and propose areas that should be protected in order to maintain the evolutionary history of those areas. For this purpose, we used available mitochondrial data for six animal species widely distributed in the Caatinga, including: three lizard species, one amphibian and one spider. We used an interpolation method to generate a genetic diversity surface for each species. Finally, we overlapped the genetic diversity surfaces of all species to determine areas that concentrate high genetic diversity. In general, southern, central and northwestern portions of Caatinga harbor the highest values of genetic diversity, despite being poorly represented within protected areas. Our results highlight the complex evolutionary history within the diagonal of open formations. Besides, we identified genetically diverse areas within the Caatinga that are of utmost importance for biodiversity conservation.

2
  • FLÁVIA MÓL LANNA
  • Evolutionary history of dwarf-geckos (Lygodactylus, Gekkonidae) in South American continent

  • Advisor : ADRIAN ANTONIO GARDA
  • COMMITTEE MEMBERS :
  • ADRIAN ANTONIO GARDA
  • FABRÍCIUS MAIA CHAVES BICALHO DOMINGOS
  • SIMONE NUNES BRANDÃO
  • Data: Feb 21, 2017


  • Show Abstract
  • What processes and mechanisms are responsible for species diversification? This old question has been revolutionized with technological and methodological advancements, and is now being understood in a way that was previously not possible. Phylogeography is a multidiscipline that uses tools derived from biogeography, molecular phylogeny, and population genetics to understand the context of gene distribution in time and space. The present study uses phylogenetic and phylogeografic analyses to infer the determinant processes in the diversification of the lizard genus Lygodactylus in the Seasonally Dry Tropical Forests (SDTF) in South America. In the first chapter we investigate the relationships among South American Lygodactylus species, seeking to understand the influence of the Pleistocenic Arc on its diversification and whether these species represent a monophyletic group. Through phylogenetics and species delimitation analyses we recovered the group's monophyly when compared with African species and recognized L. klugei as a complex o cryptic species. We suggest an increase from two to five species of Lygodactylus in South America. The divergence time among L. klugei and candidates species endemic from SDTFs was not congruent with the Pleistocenic Arc Hypothesis. However, we suggest the fragmentation of SDTFs likely influenced the divergence of L. wetzeli and a candidate species endemic from a SDTF enclave within Cerrado biome (São Domingos, Vale do Paranã region). In the second chapter we investigate the diversification within the Caatinga, testing the role of the São Francisco River (SFR) as a prominent geographic barrier. We used a lizard endemic from this region (L. klugei) as study model. We delimited the existent lineages, investigated the genetic relationships between them, the spatio-temporal diffusion history and to test the riverine hypothesis (barrier to gene flow) we used a migration analysis. We recovered two lineages structured to respect to SFR: one northern and other southern. The lineage divergence occurred 295 kya, congruent with the change of course of the SFR to the current position. We found no influence of the paleo-SFR on L. klugei structure.

3
  • ISABELA FREITAS OLIVEIRA
  • fruit-feeding butterflies in an urban landscape

  • Advisor : MARCIO ZIKAN CARDOSO
  • COMMITTEE MEMBERS :
  • DANILO BRANDINI RIBEIRO
  • MARCIO ZIKAN CARDOSO
  • MIRIAM PLAZA PINTO
  • Data: Feb 22, 2017


  • Show Abstract
  • Com o crescimento populacional e a expansão das cidades, o processo de urbanização e sua influência sobre a biota local entraram no hall de estudos ecológicos. Áreas verdes em meio a prédios e ruas tendem a se comportar como ilhas, servindo de refúgios para diversas espécies. O presente estudo teve o objetivo de entender quais fatores (e.g. cobertura vegetal) determinam a estrutura das comunidades de borboletas frugívoras em praças públicas e qual a influência de grandes áreas preservadas (Parque das Dunas e Parque da Cidade) na dinâmica das borboletas nas praças. Além disso, averiguamos se as comunidades de borboletas em diferentes hábitats possuem diferentes características ecológicas. Foram selecionadas 18 praças em três categorias de distância para o Parque das Dunas: Camada 1 (0 a 1000 m), Camada 2 (1001 a 2000 m ) e Camada 3 (2001 a 3000 m). Em cada camada de distância selecionamos 2 praças pequenas (1000 - 3000 m2), 2 médias (3001 - 5001 m2) e 2 grandes (> 5001 m2). Três pontos dentro do Parque das Dunas foram escolhidos como área controle. Após 11 meses de coleta, foram registrados 635 indivíduos de 13 espécies de borboletas frugívoras. Nas 18 praças encontramos 475 indivíduos de 9 espécies, e nos três pontos no Parque das Dunas registramos 160 indivíduos de 12 espécies. O baixo número de espécies encontradas na cidade é reflexo de uma homogeneidade local consequente de uma matriz quase impermeável. Foi possível verificar que nos períodos de chuva, a abundância aumenta significativamente nas praças, revelando que, quando a precipitação aumenta, a matriz se torna mais permeável, permitindo o deslocamento dos indivíduos e até mesmo o aparecimento de espécies encontradas predominantemente em florestas. As curvas de rarefação mostraram que o Parque das Dunas abriga mais espécies do que as praças, e que a riqueza de espécies não foi significativamente diferente entre as categorias de distância para o Parque e nem entre o tamanho das praças. A composição de espécies também foi significativamente diferente entre parque e praças e os valores dos componentes da beta diversidade revelou que a comunidade de borboletas é dominada por aninhamento. Com a seleção de modelos, foi possível selecionar os melhores modelos que explicam a riqueza e abundancia das espécies nas praças. Para riqueza, o melhor modelo foi o nulo, seguido por número de árvores frutíferas. Já para abundância, dois modelos foram selecionados: o primeiro, com as variáveis árvores frutíferas, cobertura vegetal e distância para o Parque das Dunas. E o segundo, árvores frutíferas, cobertura vegetal, distância para o Parque das Dunas e cobertura vegetal do buffer de 100 metros. Esses resultados indicam que tanto o efeito local quanto da paisagem são importantes para entender a distribuição de borboletas em uma paisagem urbana e para que estratégias de conservação sejam tomadas corretamente. 

4
  • MARCOS ROBERTO MONTEIRO DE BRITO
  • Effects of habitat fragmentation on fruit-feeding butterflies (Lepidoptera: Nymphalidae) in Atlantic Forest remnants in Rio Grande do Norte

  • Advisor : MARCIO ZIKAN CARDOSO
  • COMMITTEE MEMBERS :
  • DANILO BRANDINI RIBEIRO
  • MARCIO ZIKAN CARDOSO
  • MIRIAM PLAZA PINTO
  • Data: Feb 23, 2017


  • Show Abstract
  • Habitat loss and fragmentation are among the biggest threats to biodiversity, contributing to declines in biological communities. The response to these disturbances depends on landscape metrics and also metrics intrinsic to the fragments, and can also vary among different species. Our study test how fragment area, isolation, shape, matrix quality and distance to the nearest permanent course of water (river or pond) affect fruit-feeding butterflies richness and abundance in the northeastern portion of Atlantic Forest. We sampled 15 fragments, surrounded by a heterogeneous matrix, consisting predominantly of sugarcane crop fields, ranging from 1,7 to 27,4 hectares, spread in distance classes to a permanent course of water ranging from zero and 2000 meters. Species richness and abundance decreased with increased distance to water. Model selection suggested distance to the water as the main factor affecting species richness and abundance, but matrix quality is also an important predictor for species richness, while fragment shape is important for abundance. Our results highlight the conservation value of small fragments, and sheds light to a new relevant factor in distance to a permanent course of water as a key factor for fruit-feeding butterflies communities in the Atlantic Forest.

5
  • BRUNA MARIA BRAGA FIGUEIREDO
  • Seasonality as a modulator of the diversity of Decapoda crustaceans of  tropical region

  • Advisor : FULVIO AURELIO DE MORAIS FREIRE
  • COMMITTEE MEMBERS :
  • FULVIO AURELIO DE MORAIS FREIRE
  • TIEGO LUIZ DE ARAÚJO COSTA
  • ARIÁDINE CRISTINE DE ALMEIDA
  • Data: Mar 29, 2017


  • Show Abstract
  • The decapod crustaceans represent one of the groups more plentiful and diverse in  marine environments in consolidated and unconsolidated areas. Constituent coastal regions are the major portion of human population density and, through direct and indirect actions, may negatively impact diversity and population structure and assembly. So, the study aimed to analyze the richness and seasonal and spatial crustacean fauna decapod accompanying the shrimp trawling Xiphopenaeus kroyeri, in city of Baía Formosa, Rio Grande do Norte, constituting an official first species list, with bycatch data of trawling, for the state and a distribution study. The field work were in the litoral regions of not consolidated in the municipality of Baía Formosa, monthly (March / 2013 to February / 2015), through a small fishing boat with a single type door net trawl, 6 tows georeferenced standardized time (20min), collected as being environmental variables susceptible to seasonal variation like water transparency (g / L), pressure (kPa), salinity (ppm), dissolved oxygen (mg / L), pH, temperature (° C ), rainfall (mm) and wind speed (m / s). Were captured total hum of 23,218 animals, which belong to Achelata, Brachyura, Caridea, Dendrobranchiata and Anomura, totaling 57 species, among them: Acetes americanus, Alpheus intrinsecus, Nematopalaemon schmitti Xiphopenaeus kroyeri, Litopenaeus schmitti, Callinectes ornatus and Petrochirus Diogenes, as the specie more abundant. Besides the new occurrence for state (Lysmata. cf. bahia), there are species with a lot of economic appeal, as Xiphopenaeus kroyerii, which got a greater abundance, showing the importance of preservation this area. For the other species, the result already expected for the region, since the animals described are found in regions with similar geographical features.

6
  • RENATO JUNQUEIRA DE SOUZA DANTAS
  • Trophic ecology of Octopus insularis: methodological comparisons and new perspective through the use of stable isotopes

  • Advisor : TATIANA SILVA LEITE
  • COMMITTEE MEMBERS :
  • CRISTIANO QUEIROZ DE ALBUQUERQUE
  • RODRIGO FERREIRA BASTOS
  • RONALDO ANGELINI
  • TATIANA SILVA LEITE
  • Data: Apr 10, 2017


  • Show Abstract
  • Octopuses are mollusks that play a significant role in marine food webs, not only for their importance as prey to top predators, but also because they are carnivorous consumers of the benthic environment. For this reason, their feeding ecology has been studied using multiple methodologies applied to a variety of species of the group. However, there is no consensus on which technique would be more effective in this type of research, or even if there is only one "ideal and self-sufficient" method. Another issue relates to the positioning of the octopus in the marine food webs. It is known that they feed on a wide variety of crustaceans, mollusks, fish and other organisms and that they serve as food for many top consumers, but their ecological function remains undefined, making it difficult to predict the effects of their increase or decrease in shallow water marine communities. Therefore, in order to bring answers to these two questions, this study aims to compare three distinct quali-quantitative methods to characterize the food habits of octopuses (i.e. analyses of gut contents, of prey remains in midden piles and of stable isotopes) and to identify the trophic position of these cephalopods and their importance as prey and predators. The study object is the Octopus insularis, the most frequent octopus on the northeast coast of Brazil and its oceanic islands, and which have already being regularly exploited by artisanal fisheries in the country. The study areas are the Rocas Atoll Biological Reserve, an insular, pristine and unique environment in terms of Southern Hemisphere; and Rio do Fogo, a costal environment with human presence and fisheries impact

7
  • MARYANE CHRISTINA SILVA DAMASCENO FERREIRA
  • The influence of the fragmentation in the occurrence of neotropical primates in risk of extinction in Brazil

  • Advisor : ADRIANA MONTEIRO DE ALMEIDA
  • COMMITTEE MEMBERS :
  • ADRIANA MONTEIRO DE ALMEIDA
  • LEANDRO JERUSALINSKY
  • MARCIO ZIKAN CARDOSO
  • Data: May 15, 2017


  • Show Abstract
  • The species of Brazilian primates Callicebus barbarabrownae, Callicebus coimbrai e Sapajus xanthosternos are at risk of extinction. One of the causes of this scenario is the fragmentation of the areas of occurrence of these species in the Caatinga and Mata Atlântica. This study has as objective characterize the fragments with occurrence to each one of these three species, as well compare them with a) remaining presence in the landscape where each species is inserted; b) compare the three species about the characteristics of the fragments where they inhabit, considering the inherent differences between each species and each biome. To generate the forest fragments of the distribution area of each species and identify fragments with confirmed presence it was utilized records of occurrence of the species and images of satellite of the Normalized Difference Vegetation Index (NDVI) shared by Hansen at al (2013). To characterize the fragments were utilized several metrics of the landscape. These three species of primates usually occurred in small, regular and with complex borders fragments. However, when it was compared with their respective distribution areas, the three studied species usually occurred in fragments with bigger area and more complex borders, demonstrating that these primates do not occur by coincidence. To C. coimbrai the size of the nearest neighboring fragment showed as more important than isolation. Their fragments with occurrence have bigger rate of proximity than the fragments of the area of the distribution, what infer in a bigger presence of fragments in the matrix. Among the analyzed characteristics of the fragments, the form (perimeter/area and complexity of the border) was the most determined in the occurrence of these three species of primates in fragmented environments. After the form, the most important explanatory variables were area and isolation (to C. coimbrai). When the there species were compared, it was observed that C. barbarabrownae had inhabited smaller and more regular areas, with less complex borders and more isolated than other two species, possibly because of its inhabitation in Caatinga, when the other two species predominately or just occurred in Mata Atlântica. Callicebus coimbrai and S. xanthosternos showed fragments with similar occurrence about their characteristics of form and isolation, possibly because they have inhabited the same over-fragmented habitat despite that they have differences not only in the use, as in the requirement of resources. Thus, it was concluded that these three primates require emergency measures of conservation that consider the characteristics that determine the occurrence of these species and promote the protection, restoration, and connectivity of the areas with the occurrence of these species of primates.

8
  • RAUL MARIO DA SILVA PEIXOTO NETO
  • LITTER DECOMPOSITION PROCESS ACTING AS A FACILITATION MECHANISM

  • Advisor : GISLENE MARIA DA SILVA GANADE
  • COMMITTEE MEMBERS :
  • ADRIANO CALIMAN FERREIRA DA SILVA
  • ALEXANDRE VASCONCELLOS
  • GISLENE MARIA DA SILVA GANADE
  • Data: May 29, 2017


  • Show Abstract
  • Facilitation is a interaction in which one plant species (nurse) has a positive effect on the development and survival of other plant species by increasing resource availability or providing better abiotic conditions. Nurse tree species might facilitate other plants growing under their canopy by providing nutrient supply below and around their crown. Leaf litter decomposition, is the major nutrient transfer pathway from vegetation to soil. Thus, leaf quality, leaf biomass production and leaf decomposition rates can influence soil fertility and consequently plant productivity below nurse canopies. However, external sources such as animals, atmospheric dust and leaching also contribute to soil fertility. Although the studies that investigate plant facilitation through nutrient availability below tree canopies acknowledge the role of leaf litter decomposition, they do not assess how facilitation might act directly on litter decomposition. Leaf decomposition depends on biotic and abiotic factors, and leaf nutritional quality is one of the most determinant for defining the speed of decomposition. However, several studies report the effects of diversity and species richness on leaf litter decomposition. In forest ecosystems with high diversity, leaves of several trees form a mixed leaf litter layer. Therefore it is also necessary to assess the effects of leaf species richness on decomposition rates.  The present study aims to investigate whether nutrient transfer from tree species to soil by leaf decomposition is able to influence facilitation and inhibition interactions between plant species. Fourteen typical and abundant Caatinga species were classified as facilitators, neutral or inhibiters, according to their interspecific interaction index “INE” (Fagundes et. al., 2016).  Leaf fall rates, leaf nutritional content (C and N) and leaf decomposition rates of each species were measured. The product of these three measurements was considered as the nitrogen transfer potential from tree to the soil for each species (PTN). The results indicated that nurse species have a greater nutrient transfer potential than inhibitory species, indicating that "PTN" may be one of the factors that influence facilitation interactions between plants. A leaf mixed litter experiment using nurse or inhibiting species was also carried out to assess richness effects on decomposition. Leaves were mixed at 04 different richness levels (2, 4, 7 and 14), forming 15 different compositions. The species compositions containing nurse species showed a positive effect on decomposition rates, while species compositions containing inhibitory species had a negative effect. There was no significant effect of increasing species richness on leaf litter decomposition processes. These results indicate that leaf mixture effects on litter decomposition rates depend on the species present in the compositions and not on richness. From the results obtained in this study it is concluded that leaf litter decomposition might play an important role on the Facilitation process.

9
  • LEONARDO DANTAS MACHADO
  • Demographic and movement parameters in frugivorous butterflies in contrasting environments

  • Advisor : MARCIO ZIKAN CARDOSO
  • COMMITTEE MEMBERS :
  • MARCIO ZIKAN CARDOSO
  • GILBERTO CORSO
  • ONILDO JOÃO MARINI FILHO
  • Data: Aug 15, 2017


  • Show Abstract
  • Currently, habitat fragmentation has been one of the major factors in changing the physiognomy of landscapes and habitats. Understanding how this influences the dispersal and movement of animal species may be crucial for future, conservation and management projects, to take into account this type of behavior of the species. In this study, using as an experimental model a food guild of frugivorous butterflies, we tried to understand how species specialists in forest and generalist species move in a landscape where there is a fragment of Atlantic Forest and neighboring habitats with distinct characteristics of the original forest, a plantation of Acacias and a coqueiral, in different seasons of the year (dry and rainy). Using a capture-mark-recapture method and a multi-state mode approach, we observe that specialists individuals move less between habitats during the dry season and move more during the rainy season and that the reverse occurs with generalist individuals. It is concluded that the movement behavior of frugivorous butterflies depends both on the group (specialist or generalist) in which the species is, and on the season (dry or rainy), as well as on the preferential habitat. From now on, it is necessary to consider the o movement behavior and dispersion in future studies and conservation of the species projects

10
  • CLARICE DE ANDRADE CORDEIRO DA SILVA
  • Global trends on inland fishery

  • Advisor : ADRIANA ROSA CARVALHO
  • COMMITTEE MEMBERS :
  • ADRIANA ROSA CARVALHO
  • JULIANA STRIEDER PHILIPPSEN
  • RONALDO ANGELINI
  • Data: Aug 29, 2017


  • Show Abstract
  • The benefits of small-scale freshwater fisheries In addition to consumption for food security, they make an important contribution to an economy both locally and regionally, as well as on an international scale, in this way, with the objective of investigating how the Quantities, hake and the values generated by different modes of freshwater fishing in the world and test a hypothesis of an economic contribution of small-scale continental fisheries is higher in developing countries than other forms of freshwater fishing in developed countries. For this, a systematic review of the literature and synthesis of information was made. Thus, it could be observed that in the period 1998-2015 the freshwater fisheries production, accumulated a loss of 1.3 millions of ton. Freshwater fishery production abruptly decreased markedly from 2010 onwards. At first the lower fishery production could be attributed to the fewer recording. However, from 2010- 2015 the gross returns globally increased at USD 10 trillions per year. Subsistence fishery was chiefly recorded in Africa and the small-scale fishery was prevalent in South America. The highest fishing production was recorded in USA (mostly recreational) and in Mali, in western Africa. The development of FWF is still encouraged in those areas were inland water bodies are under-utilized and poor managed, but data gathered here suggested otherwise; freshwater environments should be indeed monitored and conserved aiming management since fishery has been intensively performed in these areas through the world

11
  • DANIEL RODRIGO DE MACÊDO MAGALHÃES
  • The Role of EPA (Environment Protected Area) on Conservation of Brazilian’s Biodiversity

  • Advisor : EDUARDO MARTINS VENTICINQUE
  • COMMITTEE MEMBERS :
  • EDUARDO MARTINS VENTICINQUE
  • LUIZ ANTONIO CESTARO
  • ROSE EMÍLIA MACEDO DE QUEIRÓZ
  • Data: Nov 24, 2017


  • Show Abstract
  • Protected Areas are the main strategy to protected biodiversity. Protected Areas are not equal and vary in their management objectives and level of human occupation. Brazil has 12 protected area's categories. Among those, "Environment Protected Area" (EPA, Category V in IUCN Classification), is the one with least restriction to human activity. This category has many critics, that argue EPAs should not be account as Protected Areas, as has defenders who argue that EPA belong to a “New Paradigm” of Protected Areas, aimed to reconcile biodiversity conservation and human development. EPAs has special importance because it covers a third of the protected land, and more than 60% on biomes such as Atlantic Forest, Cerrado, Caatinga and Pampa, and more than 80% of all marine protected areas. Therefore, understand the implementation, land cover and management patterns is crucial for Brazilian biodiversity conservation. We find levels of human occupation is low within EPAs if compare with the biome, especially if we consider only the biome that is not protected by other protected areas and indigenous
    areas. Nonetheless, we found about 7 million people live inside EPA and that in 2016, Amazon biome was the only biome with more than 50% of forest land cover. We find that if we do not account for the area with anthropogenic use inside EPA, the total area cover by protected area in Brazil would go from 17,6% to 12,8%. We also found that
    only 18% of EPA had a &quot;management plan&quot; and 45% had a "management council". Lastly, we recommend starting a discussion about specific management and support mechanism to the EPA category.

12
  • MARIA LENICE VENTURA DINIZ
  • Stoichiometric regulation of heterotrophic bacteria in low latitude freshwater ecosystems

  • Advisor : ANDRE MEGALI AMADO
  • COMMITTEE MEMBERS :
  • ANDRE MEGALI AMADO
  • JOSE LUIZ DE ATTAYDE
  • Simone Jaqueline Cardoso
  • Data: Dec 19, 2017


  • Show Abstract
  • The heterotrophic bacteria are important nutrient mineralizers (e.g. nitrogen [N] and phosphorus [P]) to the aquatic environment, subsidizing primary production and incorporating organic carbon from the organic matter into its biomass through secondary production. These processes are affected by environmental factors such as temperature and nutrient availability (Hall et al. 2009, Berggren et al. 2012, Fonte et al. 2013); are also determined by species identity and physiological status. The availability of nutrients can affect the chemical composition of bacteria, as these can affect the chemical composition of their predators and so on; This stoichiometric imbalance between the resource and the consumer influences the patterns of nutrient recycling in ecosystems, affecting their functioning and biogeochemical cycles (Sterner et al. 1998). One way to deal with nutrient variation is the regulating ability that individuals have, and in the face of disturbances in the stoichiometry of their resource, bacteria can behave in a homeostatic or flexible way. For bacteria these characteristics seem to be dictated by the composition of the community, influenced by the trophic state of the ecosystems. Thus, homeostatic behavior is expected to be predominant in eutrophic environments, while flexible behavior is predominant in oligotrophic environments (Godwin & Cotner 2015b). In order to determine the degree of community homeostasis, controlled trials are necessary to evaluate the composition of bacterial C, N and P against the exposure of a community to substrates with different C: N: P ratios. This type of experiment is performed on chemostats, which represent a method of culturing microorganisms under controlled growth stationary conditions in a stable chemical environment. The objective of this work was to test the effect of the degree of productivity of the system on the variability of the stoichiometry of bacteria and their resources in tropical lakes of low latitude. Hypotheses: (i) The variability of the stoichiometric ratios of the bacteria and their resources are smaller in a eutrophic reservoir than in an oligotrophic pond; and (ii) The degree of homeostasis of bacterial communities increases with the degree of productivity of the system. We first investigated the variability of stoichiometric ratios in two lakes, one eutrophic (Gargalheiras) and one oligotrophic (Bonfim) under an environmental approach, where monthly measurements were made of the chemical composition of the bacteria and their resource. Under an experimental approach, it was tested by manipulating the C:P ratios of the culture medium in chemostats, the degree of homeostasis of bacterial communities from 11 lakes distributed along a productivity gradient from the coast to the semi-arid region of Rio Grande do Norte. The results show that Bonfim has a high variation in the stoichiometry of the bacteria and its resource; in Gargalheiras, the C:N:P ratio of the bacteria varies little in relation to a greater variation of their resource, this shows an indicative of homeostasis in these communities. For the chemostats, the communities are homeostatic up to a C:P ratio of approximately 1000:1, with the increase of this ratio, they seem to accompany their resource, showing part homeostatic, part flexible, independent of the trophic state of the environment from where they came.

Thesis
1
  • ANA HELENA VARELLA BEVILACQUA
  • Ecological and socioeconomic factors for supporting Ecosystem Management of Fisheries

  • Advisor : ADRIANA ROSA CARVALHO
  • COMMITTEE MEMBERS :
  • ADRIANA ROSA CARVALHO
  • RONALDO ANGELINI
  • GUILHERME ORTIGARA LONGO
  • BEATRICE PADOVANI FERREIRA
  • CARLOS EDWAR DE CARVALHO FREITAS
  • Data: Feb 23, 2017


  • Show Abstract
  • Marine fishery resources are of great economic, social and ecological importance, as they guarantee food security and make up a significant part of the population's protein diet. They are still responsible for social integration and income generation for many fishers and workers directly and indirectly linked to Sector. Small-scale fisheries are of major importance in developing countries. However, although it occurs to a lesser extent, small-scale fisheries also exploit stocks that require proper management. It is known that the impact of fisheries goes beyond the more commercialized species, since often non-target species are caught accidentally during the activities. To date, fisheries management is still ineffective, focusing on a single target species, ignoring habitat, predators and preys of species and other components of ecosystems. In this way, the present work intends to bring updated and relevant information that can be used to subsidize the proposals of policies of ecosystem management of the fishing activity. The first chapter combines scientific knowledge and fisherman's traditional knowledge in the ecosystem modeling of fisheries. The second chapter provides modeling of the small-scale fishing value chain, identifying stakeholder participation and how the economic benefits are distributed along the chain. The third chapter has as main objective to analyze economically the relationship between income dependence of small scale fishing activity and the different degrees of influence of tourism in coastal communities. The 4th and 5th chapters present an analysis that aims to describe the characteristics of the composition of landed species, aiming at a better understanding of the dynamics of the socio-cultural system that influence the capture of natural resources, with emphasis on the coastal environment. The methodologies presented here and the results obtained open the way for the discussion of the use of the ecosystem approach to fisheries in the elaboration of management plans.

2
  • LEONARDO HENRIQUE TEIXEIRA PINTO
  • Restoration of plant diversity and ecosystem functioning: effects of species richness, phylogenetic distance, functional diversity and invasive plants

  • Advisor : GISLENE MARIA DA SILVA GANADE
  • COMMITTEE MEMBERS :
  • CARLOS ROBERTO SORENSEN DUTRA DA FONSECA
  • GISLENE MARIA DA SILVA GANADE
  • JOHANNES KOLLMANN
  • JOSE LUIZ DE ATTAYDE
  • WOLFGANG W. WEISSER
  • Data: May 24, 2017


  • Show Abstract
  • Biodiversity positively affects several ecosystem functions. Nevertheless, the mechanisms by which biodiversity affects ecosystems are still poorly understood and call for new experimental studies designed to identify its underlying components. Previous studies have suggested that more diverse plant communities can provide more ecosystem stability due to complementarity and redundancy effects. Plant species diversity can act on different levels of the ecosystem properties. A clear example is the effect of plant diversity on nutrient dynamics of terrestrial ecosystems. Plant diversity can alter rates of soil nutrient accumulation and nutrient loading in aquatic systems. However, human impacts on natural ecosystems are leading to habitat and biodiversity loss. Such losses will ultimately jeopardize ecosystem functions and its associated services that are vital for human well-being. Therefore, the development of adequate restoration projects is paramount to mitigate anthropogenic impacts, while contributing to the conservation of biodiversity. Restoration projects offer the possibility to develop a solid knowledge on the functioning of ecosystems facing disturbance. For achieving this knowledge, we need to conduct theory-based restoration experiments in order to assess the variability, predictability and reliability of functioning from restored ecosystems. In this context, this PhD thesis is based on three experiments testing how plant diversity and functional traits would influence the functioning of restored ecosystems. The objectives are to investigate (i) the plant species and traits that are most efficient for retaining nutrients in the soil, thus reducing nutrient leaching losses and its consequent impact on aquatic systems; (ii) the effects of plant species richness and phylogenetic diversity on restoration success (measured as biomass production and plant survival) in a recently restored riparian forest; and (iii) the influence of an invasive alien plant species on soil and soil water nutrients in communities with different levels of functional diversity. The experiments conducted during this thesis are in accordance with recent studies that investigate how different measures of biodiversity and sources of stress could affect ecosystem functioning. The main results of this thesis reveal that (i) only one species (Mimosa tenuiflora) could influence water cleaning and soil nutrient content. Additionally, plant traits related to shoot dry matter content (SDMC) and root water content (RWC) are more important for controlling individual functions related to water and nutrient retention in the soil, while only traits related to biomass production affected ecosystem multifunctionality; (ii) the use of phylogenetically distant species can increase restoration success by positively affecting plant biomass production; and (iii) plant functional diversity partially promotes water cleaning and soil fertility in restored systems, nevertheless did not prevent invasion. In turn, invasive species disrupts the influence of plant diversity on soil nutrient dynamics by jeopardizing native plant biomass production thus, potentially, creating a positive feedback for further invasions. These results support future restoration projects focusing on invasive species control and ecosystem functions, indicating which species are most suitable for restoration to maximizing soil fertility and soil water quality. Finally, this thesis offers a contribution to the knowledge of plant-soil feedbacks.

3
  • CAROLINA MARIA CARDOSO AIRES LISBOA
  • Sexual Selection and Visual modelling in Cnemidophorus ocellifer

  • Advisor : GABRIEL CORREA COSTA
  • COMMITTEE MEMBERS :
  • ADRIAN ANTONIO GARDA
  • DANIEL OLIVEIRA MESQUITA
  • DANIEL MARQUES DE ALMEIDA PESSOA
  • GABRIEL CORREA COSTA
  • MOACIR SANTOS TINÔCO
  • Data: Jun 21, 2017


  • Show Abstract
  • Many lizards have acute visual systems with retinal photoreceptors that are sensitive to UV wavelengths, and display UV-reflecting color patches. In this study, we used UV full-spectrum reflectance spectrophotometry to collect data from Cnemidophorus ocellifer UV structural colouration. Using an arena-form experimental set, we obtained evidence for the role of UV signaling in sexual selection (mate choice and male-male interactions). Our results showed that UV chroma is important in female association preference, as females exhibit spatial preference for males of higher UV reflectance over males with experimentally reduced UV reflectance. We also found that, in staged encounters, C. ocellifer males with experimentally reduced UV reflectance were not more likely to lose contests than control males, but reflectance was negatively correlated with evaluation time. We also tested two male ornaments in C. ocellifer against morphological traits and physiological performance to assess whether colour signals are informative for male quality traits. We found that larger males had more intense short (UV) and medium wavelength chroma on dorsolateral eyespots and, in contrast, smaller-headed males had more intense UV chroma on outer ventral scales (OVS). We concluded that the same colour trait convey different messages depending on the body position of the signal, perhaps indicative of alternative signalling strategies. Moreover, higher brightness on OVS signals were associated with stronger bite force, being a reliable signal of fighting ability. These results suggest that there is a multiple signalling system in our model species. Finally, we modeled the visual system of C. ocellifer, snake and avian predators to access how colour patches appear to the receivers We found that there are colour dimorphism between sexes, with UV signals of males more conspicuous in reflectance and highly distinguishable from females to conspecifics visual system. UV signals were highly perceptible from body colouration and from natural background to conspecifics and less but still perceptible to predators, agreeing with sensory drive hypothesis. This thesis enlighten the role of sexual signals and their importance on intra and interspecific communications in lizards. Our findings support further studies on evolution and behavior and expand the knowledge on natural and sexual selections iniciated by Darwin.

4
  • MARINA ANTONGIOVANNI DA FONSECA
  • Fragmentation, Conservation and Restoration in the Caatinga biome

  • Advisor : CARLOS ROBERTO SORENSEN DUTRA DA FONSECA
  • COMMITTEE MEMBERS :
  • CARLOS ROBERTO SORENSEN DUTRA DA FONSECA
  • DEMETRIO LUIS GUADAGNIN
  • GABRIEL CORREA COSTA
  • GISLENE MARIA DA SILVA GANADE
  • LEANDRO REVERBERI TAMBOSI
  • Data: Jun 22, 2017


  • Show Abstract
  • The Caatinga Biome is spread over 826,411 km2 of the Brazilian Northeast and, between the bioclimatically similar regions, is the most diverse. Although significant advances have occurred in recent years, the Caatinga remains the least known Brazilian biome in terms of its biodiversity and the conservation status of its remnants. The filling of this gap is urgent, since the Biome already has approximately 50% of deforested areas and the rest is under strong pressure by firewood extraction, livestock, hunting, mining, among others. These facts, coupled with the low representativeness of the Caatinga in Conservation Units, threaten the biological patrimony of the Biome, making urgente studies that guide conservation strategies. The adoption of conservation strategies based on the structural characteristics of the landscape has generated relevant results, guinding efficiently and quickly field surveys and public environmental policies. This thesis is organized in four independent chapters that aim to expand, mainly based on analysis of the landscape structure, knowledge about the state of conservation and fragmentation of the Biome, allowing the identification of strategies and areas more relevant to the maintenance and recovery Of the biota. The first chapter, titled "Characterization of the Caatinga Biome Fragmentation", brings an analysis of the size, functional and structural connectivity and edge effect of all Caatinga remnants, allowing identification of patterns of fragmentation and opportunities for conservation. In the second chapter, entitled "Priority Areas for the Restoration of the Caatinga", we identified, based on the connectivity of the landscape and the existence of endangered species, which river basins should be primarily targets for restoration actions. The third chapter, "Chronic Potential Disruption of Caatinga Remnants", aims to bring to light information about the potential conservation status of Caatinga remnants, taking into account the intensity and spatial distribution of vectors of anthropogenic disturbance throughout The Biome. In the fourth chapter, "Conservation Planning and Actions in a Megadiverse Country", we compare the habitat loss inside the conservation priority areas in Brazilian biomes, identifying the policies constraints and suggesting a mechanism that will allow the expansion of the protected areas system in the Caatinga.

5
  • LETÍCIA BARBOSA QUESADO
  • Spatial scale influence on geographic patterns of taxonomic and functional diversity of phytoplankton in semi-arid and coastal freshwaters ecosystems of Rio Grande do Norte

  • Advisor : LUCIANA SILVA CARNEIRO
  • COMMITTEE MEMBERS :
  • ADRIANO SANCHES MELO
  • ALEXANDRE FADIGAS DE SOUZA
  • LUCIANA SILVA CARNEIRO
  • VANESSA BECKER
  • VERA LUCIA DE MORAES HUSZAR
  • Data: Jun 26, 2017


  • Show Abstract
  • We aimed to evaluate how the spatial scale influences the taxonomic and functional composition of phytoplankton in freshwater environments distributed along an arid gradient from the (humid region) coast to the countryside (semiarid region) of Rio Grande do Norte. Likewise, we also intended to verify (i) which factors (local or regional) determines taxonomic and functional β-diversity (Chapter 1); (ii) how the relationships between functional and taxonomic metrics (richness, evenness, diversity, and functional redundancy) vary according to spatial observation scale (lake or watershed) (Chapter 2); and (iii) how environmental gradients explain the variation of phytoplankton size and functional groups (Chapter 3). We collected samples in the subsurface of the limnetic region of 98 lakes distributed along 14 watersheds, between September and October 2012. The functional metrics were based on mixed traits, as surface, size, presence of mucilage and pigment composition (green, blue, brown and mixed) and type of life forms (colonial, filamentous or unicellular). Our results show that although the environment was spatially structured mainly by watershed, the importance of space in structuring phytoplankton increased with presented a slight increasing spatial scale. Phytoplankton community was structured by species sorting at the watershed level and by the region’s and watershed’s identity at larger spatial scale. The only exception was Piranhas-Açú watershed, in which space was already structuring the community due to the great distances between its lakes. There was a strong role of functional complementarity at the local level for structuring phytoplankton communities. Opposite to what we expected, functional β-diversity was not a good predictor of local factors. Once, functional redundancy became more influent at the metacommunity level. At the regional level, both approaches (taxonomic and functional) explaining almost the entire distribution of organisms and functional traits. A positive relationship was found between all the functional and taxonomic metrics of the community (richness, evenness, and diversity). Moreover, on the contrary of what we expected, only the functional-taxonomic richness relationship increased the power of explicability with increasing spatial scale. Although the functional redundancy index weighted by abundance presented low values, it increased slightly on average with the spatial scale and was inversely related to environmental heterogeneity. These results suggest a substantial role of functional complementary at local scale for structuring phytoplankton communities and the importance of the functional redundancy at metacommunity level to maintain local communities functionally. In general, there was an increase in the average size of the phytoplankton community, with a Cyclopoida and Rotifera biomass, and reduced light availability. The predominance of SPT repeated itself within each of the functional groups, except for the non-toxic unicellular algae with hard cell wall and the toxic filamentous algae for which intraspecific variation was more important than SPT along predator (Calanoida biomass) and resource gradient (total phosphorus), respectively.

6
  • WANESSA DE SOUSA ROCHA
  • Planktonic diversity of aquatic ecosystems in a semi-arid tropical region: effects of environmental and spatial factors

  • Advisor : JOSE LUIZ DE ATTAYDE
  • COMMITTEE MEMBERS :
  • JOSE LUIZ DE ATTAYDE
  • LUCIANA SILVA CARNEIRO
  • RENATA DE FÁTIMA PANOSSO
  • ENEIDA MARIA ESKINAZI-SANT'ANNA
  • ROSEMBERG FERNANDES DE MENEZES
  • Data: Jul 7, 2017


  • Show Abstract
  • In semi-arid regions, lakes are strongly influenced by the hydrological regime. The long dry periods cause drastic reductions in water volume with a consequent decrease in inflow and outflow rates and changes in the trophic state of lakes. Because of decreased connections, we believe that biological community might be affected mainly by spatial factors during dry seasons (i.e. limitations to dispersion) and by local environmental factors during rainy periods. At dry seasons, local conditions seem more heterogeneous, increasing the beta diversity of the community. In this work, we test the hypothesis that rainy periods might increase homogeneity in the planktonic community while dry periods increase beta diversity. For this, samples were made in 40 lakes of Rio Grande do Norte state, located at Caatinga, a semi-arid region in Brazil. We performed one sample during the dry season and a sample during the rainy season (First and Second Chapters). Additionally, a long-term study of two lakes (24 months) was realized to test the effects of increases in drought severity over zooplankton community (Third chapter). Results showed that the 40 lakes were more dissimilar during the dry period, with a higher beta diversity of plankton than during rainy period. Spatial variables (i.e. geographic distances) explained more the variance in zooplankton community than local environmental predictors during the dry season. Higher beta diversity was found especially for larger planktonic organisms (i. e. mesozooplankton) with low dispersion ability. The long-term monitoring showed that the two lakes studied became different during time. Despite the eutrophic state of both lakes, they showed a contrasting phytoplankton biomass as drought period was intensified. Like the results of 40 lakes, the increase in environmental heterogeneity among the two lakes led to an increase in beta diversity of zooplankton during the dry period even with the reduction in alpha diversity in one of the lakes. We conclude that the decrease in connectivity between lakes during dry season might lead to an increase in environmental heterogeneity and beta diversity of planktonic communities.

7
  • BRUNO DE SOUZA MAGGI
  • Collor and sexual selection in Tropidurus hispidus

  • Advisor : GABRIEL CORREA COSTA
  • COMMITTEE MEMBERS :
  • ADRIAN ANTONIO GARDA
  • DANIEL MARQUES DE ALMEIDA PESSOA
  • DANIEL OLIVEIRA MESQUITA
  • GABRIEL CORREA COSTA
  • MIGUEL FERNANDES KOLODIUK
  • Data: Aug 30, 2017


  • Show Abstract
  • Within this proposal, we aim to resolve the following issues: Are there differences in coloration between males and females of Tropidurus hispidus? Do females use color traits to choose between mates? Does male coloration predicts the outcome of agonistic encounters? For that, we will use as model system T. hispidus Spix (1825), the larger species of the Torquatus group. Lizards of this genus are diurnal, extremely abundant, heliophiles, sit-and-wait foragers, and territorials, occurring predominantly in open areas. We used a spectrophotometer to measure color variables and visual modeling using the visual sensitivity data of Podarcis mularis. This data was used to answer the first question. To answer questions 2 and 3 we performed two controlled experiments with size-paired males. The first, a female mate-choice experiment in which we put males in a terraria enclosure with three separated parts. We assigned each male to a compartment in which they did not have mutual visual contact. We assigned females to the third compartment that enables visual contact to both the males. The second, a agonistic interaction experiment among males, in which we put a pair of males in a single terraria enclosure for 30 min. During the experiment period we recorded behavioral displays in order to determine winners of each trial. Separately, we used color variables to differentiate males from females. Our first results clearly showed that T. hispidus exhibits sexual dichromatism and that it is perceived as conspecific. Of the eleven areas of the body used to compare males and females, nine showed significant differences. For the dorsal region and head, the red chroma is the variable that most discriminates males from females. While for the ventral region of the thigh, cloaca, flank, belly and throat the glow is the one that best distinguishes males from females. For the base of the tail the tint better discriminates. The UV chroma in the ventral region of the tail base also distinguishes the sexes. The visual modeling showed that these differences are perceived by another lizard, confirming spectrophotometry data. In the experiment of choice by the females the region and the variable that discriminated best chosen and not chosen were respectively thigh ventral and chroma 8. For the competition experiment between the males the belly and collar regions, as well as the blue, 3 And 8 chroma variables, better discriminated winners and losers. With this, we intend to have contributed to a better understanding of the evolution of the signal design and how the intra- and intersexual selections act in this process in T. hispidus.

8
  • PATRÍCIA FARIAS ROSAS RIBEIRO
  • The Neotropical Otter (Lontra longicaudis) in Northeastern Brazil: geographic distribution and conservation. 

  • Advisor : EDUARDO MARTINS VENTICINQUE
  • COMMITTEE MEMBERS :
  • CARLOS ROBERTO SORENSEN DUTRA DA FONSECA
  • DIEGO ASTÚA DE MORAES
  • EDUARDO MARTINS VENTICINQUE
  • RENATA PARDINI
  • RENATA SANTORO DE SOUSA LIMA
  • Data: Aug 31, 2017


  • Show Abstract
  • The geographic distribution of a species is an essential information for conservation planning. This information, however, is often biased towards some regions or taxonomic groups, according to accessibility of sampling sites and natural history of studied species. Lontra longicaudis is a little studied species because of its elusive behaviour and consequent low detectability in natural environments. This situation is worse in northeastern Brazil, which for a long time appeared as a gap in L. longicaudis distribution maps. This project aimed to understand how L. longicaudis is distributed in northeastern Brazil, one of the priority actions for its conservation. This was the first specific otter survey in the region, conducted through well-designed field campaigns to 17 river basins of northeastern Brazil, in the area north of São Francisco River, between Alagoas and Piauí states. Each river basin was sampled at three stretches (lower, middle and upper courses), over about 5 km, repeatedly for four days each, looking for evidences of species presence. This amounted to an overall sample effort of 726 km in 45 sampled river stretches. In the first chapter we discuss L. longicaudis occurrence in Caatinga, a semi-arid biome where a single record of the species occurrence was reported in the literature, and which has not been considered as part of its distribution in conservation planning and strategies. We report historical and current new occurrence records of L. longicaudis in Caatinga, discuss factors that may be influencing its occurrence in the region, and propose updating the species distribution map, based on the confirmation of a real gap in its current distribution. In the second chapter we analyze environmental, climatic and anthropic factors influencing otter occupancy and habitat use on river basins of northeastern Brazil, using an occupancy-based approach and generalized liner mixed models. Detection probability of otter’s signs was high and negatively influenced by river order. Precipitation seasonality was the main determinant of L. longicaudis occupancy in the region, which is concentrated in the subregion of the river basins draining to east, where the precipitation seasonality is lower, corroborating the previously reported absence of the species in river basins totally inserted in Caatinga. This climatic variable was also important for habitat use by the species, which was more intense in lower seasonality areas, corresponding to the Atlantic forest. Northeastern Atlantic forest is the least conserved portion of this biome. In this region, otters used more rivers with lower water catchment area upstream, which correspond to smaller tributaries, providers of better environmental conditions than main rivers, being as a refuge for the species. Even using refuges, the intensity of habitat use was negatively correlated with the percentage of natural remnants, an indirect consequence of the degradation status of the most frequently used areas by the species, placing L. longicaudis in a risk status in the region. In order to understand how the northeastern Brazil otter populations is structured and contribute to its long-term persistence, in the third chapter we analyze the species genetic diversity and gene flow in the region through mitochondrial DNA and analysis of five alternative dispersal scenarios (Euclidian distance, distance through watersheds, high land dispersal cost, land dispersal cost related to distance to river, land dispersal cost related to slope). 36 noninvasive samples (fresh faeces/mucus), from seven river basins, were analyzed. Of these, 17 amplified the three mitochondrial DNA segments analyzed, and were considered distinct individuals according to sampling locality and genetic composition. These individuals are representatives of seven haplotypes, from which four were identified for the first time in this study. Estimates of genetic variability indicate high haplotype diversity whereas presenting low nucleotide variability. The greatest genetic differentiation among samples were observed in two samples from Piauí, geographically above the Caatinga area were the species absence was confirmed in this study, confirming the climatic barrier through which gene flow can had been interrupted for longer time. In spite of being semiaquatic, the dispersion scenario most correlated with genetic differentiation among sampled individuals was the high land dispersal cost scenario, emphasizing a great dependence of the species on the aquatic environment. Least cost path analyzes indicate the São Francisco River as an important dispersal route connecting coastal river basins of northeastern Brazil with basins located north of the Caatinga, which highlights the importance of São Francisco river basin conservation.

     

9
  • GUILHERME SANTOS TOLEDO DE LIMA
  • Birds of Caatinga – Individuals, populations and community-level persistence in a seasonally dry tropical forest during drought years

  • Advisor : MAURO PICHORIM
  • COMMITTEE MEMBERS :
  • MAURO PICHORIM
  • CARLOS ROBERTO SORENSEN DUTRA DA FONSECA
  • EDUARDO MARTINS VENTICINQUE
  • LUIZ AUGUSTO MACEDO MESTRE
  • RODRIGO LIMA MASSARA
  • Data: Oct 27, 2017


  • Show Abstract
  • Global climate change is expected to increase the frequency and intensity of drought events in arid and semi-arid tropical regions. Although dry spells have been natural weather events in these regions, increases in your frequency may have cumulative effects on vertebrate populations and communities, exacerbating the severity of resource bottlenecks. Vertebrates with high mobility potential such as birds respond in different ways to drought events: diet and behavior changes to explore alternative resources, regional scale movements to track food, and adjust the territory sizes to local availability of resources. However, more severe and prolonged droughts can reduce recruitment and increase mortality rates in populations of sedentary and specialist birds. Current knowledge about the effects of drought on the avifauna of arid and semi-arid regions have been based on studies in Australia and Africa, while few studies have been conducted in the Neotropics. The objective of this thesis was to understand how a community and populations of insectivorous birds responded to a prolonged drought in Caatinga, between 2012 – 2015. Data were collected in Estação Ecológica do Seridó – RN, through systematic mist-netting in a seasonal frequency. Birds were captured in two grids of 12 ha with 48 sampling points each, established in two habitats: wood and shrubby caatinga. The captured birds were marked with aluminum bands and an individual color-combination of plastic bands. In the first chapter, we used capture-marking-recapture/resighting analysis to test the effects of habitat, precipitation, seasonality and of an unusually dry period on the monthly survival rates and population densities of four insectivorous passerines. Monthly survivals of Myiarchus tyrannulus, Hemitriccus margaritaceiventer and Polioptila plumbea fluctuated seasonally throughout the study, with the lowest values recorded in the dry intervals. Formicivora melanogaster survived constantly throughout the study. Annual survival rates of H. margaritaceiventer and F. melanogaster were markedly low in wood caatinga compared to shrubby caatinga. Densities of populations were higher in shrubby caatinga over almost all monitoring, and peak density in three of them occurred just after the rainy season of 2013, which followed the driest period of the study. In the second chapter, we used multiple-season occupancy models in a community approach to estimate the relative species richness in each sampling session, colonization, and local extinction rates during the intervals between sessions. Additionally, we tested for variations related to time, habitat, and functional groups. Relative species richness or the ratio of species at the study site to the number of species in the regional pool remained low throughout the study (20% – 51%), with higher estimates in shrubby compared to wood caatinga, ~ 42% vs. ~ 31%, respectively. Pollinators, seed dispersers and ecosystem engineers were characterized by colonization rates of less than 50%, and median to high extinction rates (40% – 60%), suggesting low fidelity to the study area. In contrast, granivorous and insectivorous species were resident in the community, with both low colonization and extinction probabilities (< 30%). Finally, in the third chapter we estimate territory sizes of Formicivora melanogaster during six resighting campaigns. We tested for the effects of habitat and relative air humidity (proxy of food availability) on territory sizes through an analysis of covariance. Between October 2014 and June 2016, we monitored six adult pairs and mapped 15 territories, whose estimates ranged from 0.52 to 3.94 ha. Territory sizes were inversely correlated with relative air humidity (F = 42.07; p < 0.01) and significantly higher in wood than shrubby caatinga (F = 14.53; p < 0.01), suggesting that adult pairs of F. melanogaster adjusted their territory sizes to the availability of resources in time and space.

2016
Dissertations
1
  • FABÍOLA PATRÍCIA DA SILVA RUFINO
  • A PAISAGEM DA MATA ATLÂNTICA DO ESTADO DO RIO GRANDE DO NORTE: REMANESCENTES, CONFIGURAÇÃO ESPACIAL E DISPONIBILIDADE DE HABITAT

  • Advisor : MIRIAM PLAZA PINTO
  • COMMITTEE MEMBERS :
  • ADRIANA MONTEIRO DE ALMEIDA
  • JAYME AUGUSTO PREVEDELLO
  • MIRIAM PLAZA PINTO
  • Data: Jan 29, 2016


  • Show Abstract
  • A Mata Atlântica no Rio Grande do Norte (RN) pertence à biorregião de Pernambuco e é representada pelas Florestas Estacionais Semidecidual e Decidual, Manguezais e Restinga. Com o objetivo de avaliar o estado de conservação da Mata Atlântica no RN realizamos o mapeamento de remanescentes a partir de imagens de satélite e a abordagem de Ecologia de Paisagens. Avaliamos se há distinção entre os litorais norte e sul do Estado considerando suas diferenças naturais e de uso do solo históricas,  como se dá influência de remanescentes pequenos na cobertura e configuração da paisagem e investigamos a relação entre a configuração da paisagem e a disponibilidade de habitat do bioma para espécies com diferentes capacidades de deslocamento. O percentual da área original do bioma coberta por remanescentes que possuem área a partir de 3 hectares é de 15,60% para o limite oficial do bioma.   89,70% do número total de remanescentes possuem área até 50 hectares. Apenas 6,00% dos remanescentes tem área maior do que 100 hectares, e estes são responsáveis aproximadamente 65% da área remanescente. Os fragmentos com menor área influenciam todas as métricas calculadas. As bacias hidrográficas do litoral sul possuem maior percentual de cobertura com remanescentes, maiores densidades de remanescentes e as áreas dos fragmentos são maiores do que no litoral norte. Constatamos que a disponibilidade de habitat na Mata Atlântica do RN é baixa para todas as capacidades de deslocamento e para todas as bacias hidrográficas, e variou com a capacidade de deslocamento e com a remoção de remanescentes, mas não houve interação entre esses dois fatores. Para as espécies com pequena e média capacidades de deslocamento, a disponibilidade de habitat é influenciada pelas métricas de configuração e composição de paisagem. Para as espécies com grande capacidade de deslocamento a disponibilidade de habitat é influenciada apenas pela métrica percentual de cobertura remanescente. Portanto a influencia da fragmentação na disponibilidade de habitat para áreas com percentual de cobertura médio e baixo (4 a 35%) depende da capacidade de deslocamento da espécie em questão. A Mata Atlântica do Rio Grande do Norte apresenta-se em situação crítica de conservação, com um baixo percentual de área remanescente, um alto nível de fragmentação e com baixa disponibilidade de habitat para todas as capacidades de deslocamento testadas, sendo imprescindíveis para conservação do bioma a manutenção de toda a área remanescente, principalmente dos grandes remanescentes e a restauração de áreas para aumentar o percentual de cobertura e a conectividade da paisagem.

2
  • MARINA VERGARA FAGUNDES
  • A importância da especificidade nas interações entre plantas para comunidades semi-áridas

  • Advisor : GISLENE MARIA DA SILVA GANADE
  • COMMITTEE MEMBERS :
  • GISLENE MARIA DA SILVA GANADE
  • ALEXANDRE FADIGAS DE SOUZA
  • FLAVIO ANTONIO MAËS DOS SANTOS
  • Data: Feb 12, 2016


  • Show Abstract
  • Interações entre plantas cumprem um importante papel modulando comunidades vegetais. Os efeitos que um individuo exerce sobre seus vizinhos depende das suas alterações nas condições ambientais e na disponibilidade de recursos abióticos em seu entorno, resultando em interações positivas ou negativas. Interações negativas são evidenciadas em ambientes amenos e ao passo que o estresse aumenta, interações positivas tornam-se comuns. Ao longo do histórico evolutivo as plantas desenvolveram diferentes atributos funcionais para lidar com o estresse, deste modo, mesmo em ambientes mais estressantes, o resultado da interação depende das características das plantas que interagem, em um processo espécie-específico. Este trabalho testou a especificidade das relações das espécies arbóreas do semi-árido tropical, e se os atributos das espécies podem prever os resultados negativos e positivos. Foi conduzido um experimento com 20 espécies de plantas adultas (nurses) e 3 espécies de plântulas (targets) ao longo de 85 dias. As relações se mostraram amplamente espécie-específicas, variando com a identidade das espécies, e em diferentes medidas de desempenho para as targets. Os atributos funcionais das nurses foram importantes para apenas uma espécie de target, demonstrando que o resultado da interação varia tanto com as características das nursesquanto das targets. Medir os efeitos que uma espécieexerce na comunidade é fundamental para tomadas de decisão em programas de restauração. Os índices propostos na literatura medem as interações nurse-targetde forma pareada, não representando com eficiência os efeitos de uma nurse. Neste sentido, apresentamos um novo índice teórico que integra os efeitos da nurse em suas múltiplas relações, e comparamos os resultados com um índice pareado através de simulações. O novo índice evidencia os efeitos que acreditamos ser importantes para avaliar o impacto biológico de uma espécie, mostrando-se uma boa ferramenta em potencial para compreender as interações entre plantas a nível de comunidade.

3
  • JUAN CARLOS VARGAS MENA
  • Cave-dwelling bats in the Caatinga: Landscape and cave effects on community structure in Rio Grande do Norte, Brazil
  • Advisor : EDUARDO MARTINS VENTICINQUE
  • COMMITTEE MEMBERS :
  • ADRIAN ANTONIO GARDA
  • EDUARDO MARTINS VENTICINQUE
  • ENRICO BERNARD
  • Data: Feb 19, 2016


  • Show Abstract
  • As cavernas são abrigos importantes para morcegos em áreas cársticas e desempenham um papel fundamental para a proteção de suas populações. Vários fatores internos podem influenciar a seleção de uma caverna pelos morcegos, como o tamanho da caverna e as características microclimáticas dos substratos internos, que influenciam na riqueza e estrutura das comunidades de morcegos. Porém, os efeitos de fatores externos, como componentes da paisagem e atividades antrópicas em torno da caverna, são pouco conhecidos. Os morcegos do Rio Grande do Norte (RN) são pouco estudados apesar do estado conter mais de 900 cavernas, principalmente na Caatinga, que podem fornecer abrigos importantes para as populações locais. Os objetivos desta dissertação são 1) determinar a composição das comunidades de morcegos cavernícolas e suas colônias no estado pela primeira vez; e 2) avaliar os efeitos da estrutura da paisagem e da caverna sobre a riqueza e a estrutura das comunidades em três áreas cársticas na Caatinga do RN. Em treze cavernas, durante 37 noites, foram capturadas 16 espécies pertencentes às famílias Phyllostomidae (12), Emballonuridae (1), Mormoopidae (1), Furipteridae (1), Natalidae (1). A maior colônia achada pertenceu a Pteronotus gymnonotus (> 10 000 indiv.) e a Phyllostomus discolor (101-1000 indiv.). A Furna Feia abrigou a maior riqueza (10 spp) e foi a maior caverna pesquisada. Usando essas 13 cavernas, em um buffer de 1 km de raio, foram extraídas 14 variáveis (espaciais, antropogênicas, dimensões da caverna e ambientais) e foi realizada uma análise com modelos simples e múltiplos. Observamos que as comunidades de morcegos foram afetadas por 1) a posição espacial das cavernas (ou sistema de cavernas) dentro da paisagem estudada 2) a presença de humanos e populações de animais domésticos e 3) variáveis ambientais, de forma menos intensa. Os efeitos dessas variáveis refletiram na presença de espécies encontradas apenas em cavernas específicas e na abundância (tamanhos de colônias) de espécies compartilhadas entre as áreas cársticas. Por outro lado, verificou-se que a riqueza foi explicada pelo tamanho da caverna. Os resultados deste estudo nos levam a identificar quatro cavernas (Furna do Urubu, Gruta da Carrapateira, Caverna Boa, Gruta dos Três Lagos) como prioridade de conservação devido à sua relevância quiropterológica por possuírem grandes colônias, alta riqueza e abrigos importantes para espécies ameaçadas de extinção.
4
  • EUGENIA DE JESUS CORDERO SCHMIDT
  • Structure of mutualistic networks between bats and plants and other feeding strategies in a semiarid Caatinga forest of Rio Grande do Norte, Brazil

  • Advisor : EDUARDO MARTINS VENTICINQUE
  • COMMITTEE MEMBERS :
  • CARLOS ROBERTO SORENSEN DUTRA DA FONSECA
  • EDUARDO MARTINS VENTICINQUE
  • ISABEL CRISTINA SOBREIRA MACHADO
  • Data: Feb 19, 2016


  • Show Abstract
  • A Caatinga é uma formação florestal esclerófila, decídua e espinhosa. Situa-se em uma região semi-árida, com cerca de 730 000 km2, exclusiva do território brasileiro. Este ambiente apresenta grande variação de tipos de vegetação que foram atribuídas à variações em larga escala no clima, padrões de geomorfologia e diferenças de pequena escala em relevo e solos. A precipitação escassa e flutuante das regiões áridas e semi-áridas, exercem um forte controle sobre: histórias de vida, características fisiológicas e composição de espécies de sua biota. Pelo menos 77 espécies de morcegos das 178 espécies presentes no Brasil são encontrados na Caatinga, dos quais 13 são frugívoros e cinco nectarivoros incluindo o endémica Xeronycteris vieirai. Os morcegos são conhecidos por desempenharem papéis importantes no controle de pragas, polinização e dispersão de sementes. No entanto, pouca informação foi gerada sobre o papel ecológico dessas espécies em um ambiente como Caatinga. Em geral, esse habitat é o ecossistema brasileiro mais negligenciado em termos de pesquisa e conservação da sua biodiversidade. Especificamente no caso dos morcegos, o Rio Grande do Norte possui uma das maiores lacunas de conhecimento no Brasil. Os dados aqui apresentados, representam uma das primeiras pesquisas formais com morcegos na Caatinga do Rio Grande do Norte. Foram geradas informações sobre a estrutura aninhada e assimétrica da rede mutualística entre morcegos nectarívoros e espécies chave de plantas para a manutenção da comunidade de morcegos nectarívoros nesta região. Além disso, a primeira evidência de folivoria de pelo menos 16 espécies de plantas pelo morcego frugívoro Artibeus planirostris foi documentada. Isto representa o primeiro registro para um ambiente semi-árido e o primeiro registro para a espécie. Finalmente, o primeiro “insight” para aspectos biológicos do morcego endêmico X. vieirai, incluindo dieta, poleiros e dados de reprodução, assim como a extensão de sua distribuição a nível nacional.

5
  • REGINA LÚCIA GUIMARÃES NOBRE
  • A TALE OF TWO LAKES: FISH INTRODUCTION AND THE BIODIVERSITY OF UPLAND AMAZONIAN LAKES
  • Advisor : LUCIANA SILVA CARNEIRO
  • COMMITTEE MEMBERS :
  • LUCIANA SILVA CARNEIRO
  • KEMAL ALI GER
  • REINALDO LUIZ BOZELLI
  • Data: Feb 29, 2016


  • Show Abstract
  • Astyanax bimaculatus was artificially introduced in Violão lake, an upland Amazonian lake located on Serra dos Carajás/Brazil. This fish became abundant there, but is absent across nearby fishless lakes with similar characteristics, as is the case of Amendoim lake. This study aimed to test predictions of food-web theory regarding effects of a top predator fish introduction in these systems. Data series of biotic variables sampled on both Violão and Amendoin lakes from 2010 to 2013 were used. Lakes were very distinct regarding the structure and composition of macroinvertebrates, with communities being richer and more abundant in Amendoim lake. A difference on zooplankton composition was detected but no consistent effects were observed regarding zooplankton structure. Phytoplankton in Violão lake presented higher richness and chlorophyll-a biomass. Differences found at ecosystem-scale for macroinvertebrates community suggests descendent effects of A. bimaculatus translocation are more consistent in benthic-littoral communities than on planktonic communities. Results also indicates that A. bimaculatus has potential to couple pelagic and littoral habitat trough nutrient recycling. Our results showed differences between lakes are within the description of omnivorous fish effects on aquatic systems and thus, considering the effects of fish translocation in such aquatic ecosystems is pivotal for preserving local biodiversity.
6
  • FELIPE DE OLIVEIRA FERNANDES
  • Propagação em massa e efeito da fertilização na produção de biomassa de Gracilaria birdiae em condições de laboratório e de campo

  • Advisor : ELIANE MARINHO SORIANO
  • COMMITTEE MEMBERS :
  • ANDRE LUIS CALADO ARAUJO
  • ELIANE MARINHO SORIANO
  • MARCELLA ARAÚJO DO AMARAL CARNEIRO
  • MARCELO FRANCISCO DE NÓBREGA
  • Data: Feb 29, 2016


  • Show Abstract
  • Apesar da rápida expansão nas últimas décadas, o cultivo de macroalgas ainda não atende à demanda das indústrias por material algal. Neste sentido, é necessário desenvolver protocolos que possibilitem a implantação de cultivos comerciais e evitem a sobre-exploração dos bancos naturais. A propagação vegetativa e o cultivo sob pulsos são métodos que permitem minimizar custos e produzir uma grande quantidade de propágulos de maneira sustentável. Este estudo teve como objetivo avaliar o crescimento de propágulos de Gracilaria birdiae cultivados sob pulsos de nutrientes. O estudo foi dividido em três experimentos: (1) indoor, (2) outdoor e (3) em campo. O experimento indoor, realizado sob condições controladas, foi conduzido em 12 aquários (10L) com água do mar filtrada e 40 propágulos de G. birdiae (~ 0,5 g/L). Os propágulos foram submetidos a três tratamentos, em triplicata, com pulsos de fertilização: (T1) efluente de viveiro de camarão; (T2) fertilizante para aquariofilia (Mbreda®); (T3) fertilizante extraído de Ascophyllum nodosum (Acadian®). Uma série de três aquários (sem pulsos de fertilização) foi utilizada como controle. O experimento outdoor, onde os propágulos estiveram sujeitos às variações ambientais, foi conduzido em 12 aquários (30L), com densidade de aproximadamente 1 g/L de biomassa, e submetidos aos mesmos tratamentos descritos acima. O experimento em campo consistiu no cultivo dos propágulos dos experimentos anteriores (indoor e outdoor) no mar e em uma fazenda de camarão orgânico. Os valores positivos de biomassa e da taxa de crescimento em todos os experimentos evidenciam a viabilidade de produzir biomassa de Gracilaria birdiae da propagação in vitro até o cultivo em campo. Os propágulos cultivados no tratamento T2 e no T3 apresentaram os maiores valores de biomassa e de taxa de crescimento, assim como o maior conteúdo de nitrogênio. Isto indica que os dois fertilizantes possuem os nutrientes necessários e em proporções balanceadas para o crescimento de G. birdiae. Os propágulos cultivados na fazenda de camarão orgânico obtiveram valores de biomassa e taxas de crescimento menores do que aqueles cultivados no mar devido à maior variação da temperatura e da salinidade. Nestas condições estressantes, os propágulos do T3 demonstraram desempenho superior em virtude dos compostos bioativos presentes no extrato de A. nodosum, os quais aumentam a resistência ao estresse abiótico. De acordo com os resultados obtidos, os propágulos apresentaram maior crescimento quando cultivados sob pulsos de fertilizantes e o protocolo desenvolvido pode ser aplicado para produção de estoques de propágulos.

7
  • ALINE CAMILA MEDEIROS PINHEIRO
  • Distribution, recruitment and survival of the hard coral Siderastrea stellata (Verrill, 1868) on a sandstone reef of the South Atlantic

  • Advisor : LIANA DE FIGUEIREDO MENDES
  • COMMITTEE MEMBERS :
  • LIANA DE FIGUEIREDO MENDES
  • GISLENE MARIA DA SILVA GANADE
  • BÁRBARA SEGAL RAMOS
  • IGOR CRISTINO SILVA CRUZ
  • Data: Apr 29, 2016


  • Show Abstract
  • Reef ecosystems are known worldwide for their natural beauty and their capacity to harbor a great variety of marine life. In addition, these environments provide goods and services that encompasses social, environmental and economic spheres. However, around 20% of the world's reefs have been destroyed and 35% are threatened. In Brazil, the reefs are located along the northeast region and are usually near the coast, enabling the access of the human populations that use them for food, sport and recreation. One way to maintain reef resilience and avoid biodiversity loss would be to gather information on recruitment and survival of organisms from reef communities. The endemic hard coral, Siderastrea stellata, is one of the most resistant and common species in Brazilian reefs. Considering the ecological importance of this species of coral, we aimed to understand some aspects of its distribution, recruitment and colony maintenance. Therefore, S. stellata colonies were analyzed at different study sites in the “Parracho de Pirangi/RN”. The following activities were performed: 1) mapping colonies size (Chapter 1), 2) running recruitment experiment subjected to manipulation of calcareous algae (rhodoliths), testing the hypothesis that rhodoliths act as facilitators due its complex threedimensional structure (Chapter 2), and 3) running a health evaluation experiment of juvenile colonies in different areas of the reef, through macroalgae manipulation, testing the hypothesis that coral colony health is affected negatively by the presence of benthic macroalgae (Chapter 3). A distribution pattern in Parracho de Pirangi/RN was observed with less coral occurring in the area nearby touristic site. It is possible that impacts such as the constant suspension of sediments caused by swimmers and boats are acting as the main mechanism driving this distribuition pattern. Coral recruitment of Parracho de Pirangi was low compared to other shallow reefs from northeastern Brazil. This shows that although very resistant, the coral S. stellata is not able to establish on this reef formation. It was also noted that recruitment is not facilitated by calcareous algae that form rhodoliths. Instead, rhodolith banks sheltered abundant concentration of benthic invertebrates that might compete for space or feed on coral larvae, preventing recruitment. Generally, the health of young colonies was affected by bleaching, which increased throughout the year. This increase was correlated with low water salinity registered. However, it was notable that bleaching was lower in the treatment where benthic macroalgae was not removed. Possibly, the growth of benthic macroalgae within the limits observed over the months attenuated the effects of high solar radiation on young coral colonies, protecting them from bleaching.

8
  • MARÍLIA GOMES TEIXEIRA
  • UNIDADES DE CONSERVAÇÃO DA CAATINGA: DISTRIBUIÇÃO E CONTRIBUIÇÕES PARA A CONSERVAÇÃO

  • Advisor : MIRIAM PLAZA PINTO
  • COMMITTEE MEMBERS :
  • ADRIANA ROSA CARVALHO
  • MARILIA BRUZZI LION
  • MIRIAM PLAZA PINTO
  • Data: May 23, 2016


  • Show Abstract
  • A Caatinga é o único bioma cujos limites estão inteiramente restritos ao território nacional, sendo que ainda é tratada com baixa prioridade de investimento em conservação, sendo hoje uma das ecorregiões mais ameaçadas da terra, devido às altas taxas de conversão do uso do solo e existência de poucas áreas protegidas. O desmatamento tem sido o principal mecanismo responsável pela alteração do bioma. Essas circunstâncias despertaram nosso interesse para investigar o processo de expansão em número e área das unidades de conservação (UCs) da Caatinga, no espaço e ao longo do tempo; e avaliar a eficiência das UCs em evitar o desmatamento que ocorre no bioma, e de como a forma da UC e indicadores antrópicos da sua área do entorno influenciam o desmatamento que ocorre no seu interior. Atualmente 7,8% da área do bioma está sob proteção de 168 unidades de conservação. Não houve associação entre as esferas de gestão (federal e estadual) e o grupo de proteção das UCs, uso sustentável ou proteção integral, embora a dinâmica de criação de UCs na Caatinga tenha mudado ao longo dos anos, e siga tendências nacionais, como o aumento do número de UCs sob gestão estadual e de maior permissividade de uso, como as Áreas de Proteção Ambiental (APAs). As UCs de proteção integral foram as únicas que mostraram eficiência em conter o desmatamento que ocorre na sua área do entorno de 5 e 10 km, e as APAs foram as UCs mais suscetíveis às pressões de desmatamento externo. O desmatamento dentro das UCs está diretamente relacionado ao grupo de proteção a que pertencem. A forma da UC, densidade de estradas e proporção de vegetação no entorno das unidades de conservação não apresentaram relação com o desmatamento que ocorreu dentro dessas áreas.

9
  • VINÍCIUS PRADO FONSECA
  • SPATIAL DIVERSITY DISTRIBUTION PATTERNS AND FUNCTIONS OF ECOLOGICAL MARINE FISH IN RIO GRANDE DO NORTE, BRAZIL

  • Advisor : LIANA DE FIGUEIREDO MENDES
  • COMMITTEE MEMBERS :
  • ADRIANA ROSA CARVALHO
  • LIANA DE FIGUEIREDO MENDES
  • PAUL GERHARD KINAS
  • Data: Jun 29, 2016


  • Show Abstract
  • A of the main goals of ecology is the determination of priority areas for conservation. The designation of these areas takes into account several factors, including the ability to preserve a key species or certain biodiversity. One of the most effective ways to identify such areas is the use of statistical models to determine the degree of occupation and the presence of species spatially. With recent technological advances both computational and in the acquisition of environmental data from high resolution satellite, these tools have become increasingly robust. In marine environments, the logistics for data collection and ecological observations of phenomena is often too expensive and complicated. Thus, develop predictions for species not collected areas distributions, based on data collected at different sites associated with environmental information remotely acquired, often for free, it is essential. In this study, we used Bayesian statistical methods in order to develop predictions and generate maps of the spatial distribution of marine fish of the continental shelf of Rio Grande do Norte in northeastern Brazil. To this end, two methodologies were addressed in the form of two separate articles. In the first, spatial distribution model of species richness were developed this fauna. Then, the species were grouped into functional groups based on characteristic life history of each species for which they were developed spatial distribution models for the identification of potential vulnerability zones for ecological functions. Based on the results of both studies, we can point out two areas of important ecological value both for the preservation of large fish biodiversity as optimize the preservation of ecological functions preserving the proper functioning of this ecosystem. The first is a more remote area of the coast that includes reefs near the continental shelf break and fields of phanerogams algae, featuring a mosaic of habitats. The second is characterized by being near the coast in areas under the influence of estuaries. It is expected that the results obtained and the methodology used can be used for a future more adequate management of how well area for the development of new work with the same approach in different locations.

10
  • ANNE KARENINE BEZERRA DA PENHA DANTAS
  • Landscape characterization and habitat fragmentation of Sapajus flavius and Alouatta belzebul in the northeastern Atlantic Forest.

  • Advisor : MIRIAM PLAZA PINTO
  • COMMITTEE MEMBERS :
  • MIRIAM PLAZA PINTO
  • MARILIA BRUZZI LION
  • MARCOS DE SOUZA FIALHO
  • Data: Jul 27, 2016


  • Show Abstract
  • The effects of fragmentation process and habitat loss have generally resulted in the decrease of species richness, abundance of species and density of species as well as changes in population distribution, in addition to decreasing genetic diversity. Knowing that the arboreal primates are the most sensitive species to habitat fragmentation and are dependent on forests, these factors affect them directly with decreasing size of the fragments, increasing the insulation level and edge effect, facts that can cause change in affecting habitat quality and often setting the permanence of these species in forest remnants. In this study we first assess the structure of the landscape in the sites where the two species of endangered primates of the Atlantic Forest in north of Rio São Francisco: Alouatta belzebul and Sapajus flavius. And then we compare the fragments in which these species occur in fragments that they do not occur with respect to aspects of the landscape. In attempt to try to understand why there is absence of primates in fragments with area and socioeconomic characteristics similar to those that have occurred these primates. The CPB (Centro Nacional de Pesquisa e Conservação de Primatas Brasileiros - ICMBio) provided the occurrence data of primates and use indexing basis of specific articles and journals to compile all articles in which these species were studied in the field. We use the forest cover data from the world generated by Hansen et al. (2013), and calculated for each fragment area, perimeter, shape, proximity index and ratio of forest cover the landscape. The species S. flavius has a tendency to occur in different fragments compared with fragments only A. belzebul occurs and that both species occur mainly when compared with the proximity index (which measures the distance between the fragments). Showing that the species S. flavius tends to occur in more isolated locations. The shape, perimeter and distance of cities were the main characteristics that most explained the absence of primates in fragments without occurrence with socioeconomic data and similar area of the fragments occurring primate. This result indicates that possibly primates have preference for fragments with less edge effect and probably are suffering by human action. Conservation strategies must be proposed as resettlement connectivity as corridors and "stepping stones". And awareness work with the people surrounding the fragments is required to maintain these species threatened with extinction still alive in the Atlantic Northeast.

11
  • KARLA JULIETE DE PAIVA SILVA DE SOUZA
  • Biogeography of restingas: patterns and determinants of floristic variation on the Brazilian coast

  • Advisor : ALEXANDRE FADIGAS DE SOUZA
  • COMMITTEE MEMBERS :
  • ALEXANDRE FADIGAS DE SOUZA
  • LEONARDO DE MELO VERSIEUX
  • MARIA LUCIA LORINI
  • Data: Jul 29, 2016


  • Show Abstract
  • Aim: The plant communities of restinga are shaped by species from Caatinga, Cerrado, Amazon and Atlantic Domains which are able to cope with stressful conditions from the Brazilian coast. We tested whether environmental variation along the Brazilian coast is strong enough to impose additional filters for the restinga species.

    Location: The entire coast of the Brazil, South America

    Methods: We gathered information about species composition from 164 distinct localities along the Brazilian coast to construct a binary database of restinga flora. For each of these localities, we obtained a set of 41 environmental variables, including climate and edaphic variables. We used Species Archetype Models (SAMs) to evaluate the response of the restinga species to the variation represented by abiotic variables. We also investigated the existence of floristic gradients using a Principal Coordinates Analysis (PCoA). We use these two statistical approaches for data of herbaceous and woody species, separately.

    Results: We found four archetypes of herbaceous species in response to 10 environmental variables, and 10 archetypes of woody species in response to 6 environmental variables. The archetypes of herbaceous responded to environmental gradients more strongly than archetypes of woody species, althout, in general, just few archetypes showed strong responses to environmental variation. Additionally, the herbaceous communities from restinga were not structured by significant floristic gradients and the woody communities did not have clear floristic gradientes, suggesting a high level of stochasticity shapping the floristic structure of restinga.

    Main conclusions: The environmental variation along the Brazilian coast seems to create additional filters for herbaceous and woody species of restinga, which are more important to the distribution of herbaceous species. The low response of species to the environment suggests that the floristic variation of restinga results from a spatial relationship between the restinga and the Caatinga, Cerrado, Amazon and Atlantic Domains.

12
  • LEONARDO RAFAEL MEDEIROS
  • Unraveling Knowledge Gaps about Cyanobacterial Blooms and Proposing an Alternative for Lake Restoration

  • Advisor : RENATA DE FÁTIMA PANOSSO
  • COMMITTEE MEMBERS :
  • LUCIANA SILVA CARNEIRO
  • MARIA CRISTINA BASÍLIO CRISPIM DA SILVA
  • RENATA DE FÁTIMA PANOSSO
  • Data: Dec 28, 2016


  • Show Abstract
  • Artificial eutrophication has been considered a problem of major concern in aquatic ecosystems around the world. Since 1960, scientific advances have been made in order to develop techniques that mitigate the effects of eutrophication. Several physical, chemical and biological procedures can be used and combined to recover lakes from cyanobacterial blooms, such as the application of a flocculant combined with natural or modified clay. However, the efficacy of local dryland soils in mitigating blooms is unknown for Brazilian manmade lakes. In this paper, we present a bibliometric analysis of the evolution of publications about cyanobacterial blooms and identify records that directly aim to overcome the occurrence of these blooms. Also, we evaluate, through laboratory experiments, the effect of the combined use of flocculent polyaluminum chloride (PAC) and a local soil from the lake catchment (LS), as ballast, in controlling cyanobacterial bloom in a shallow lake of the semiarid region of Brazil. The bibliometric research was conducted with the “Web of Science” database through the search function “TS = ((cyanobacteri* or blue green algae or cyanoprokariote or cyanophyceae) and (mass accumulation or bloom or domina*))”, from 1969 to June 2016. We performed a keyword frequency analysis and quantified the number of records with a restoration approach. Besides, three sets of experiments were performed in three sampling occasions with different bloom compositions and biomass in Armando Ribeiro Gonçalves Reservoir. Our study revealed that studies about cyanobacterial blooms increased exponentially and their quantitative impact on the aquatic sciences increased significantly along the years (F = 97.52; p < 0.0001). The USA stands out as the most productive nation, followed by China and European countries. China has impressively increased its contribution to this area, surpassing the USA in the last five years. Studies about Microcystis and toxins, such as microcystins, are trends in research, due to their ubiquitousness and historical negative consequences. We also emphasize the need for more studies aiming at developing techniques to solve and/or mitigate the issue of blooms. In view of this, our experiments revealed that the use of PAC and LS had a remarkable effect on cyanobacterial biomass in the water column in all samplings, reducing up to 90% top chlorophyll-a concentration. The use of LS alone was inefficient to settle blue-green-algal biomass. In two samplings, the combination of flocculant and ballast exhibited the same efficacy as the use of solely PAC. Even so, the use of LS is important to ensure sedimentation. Combined with PAC, LS was as efficient a ballast to remove cyanobacteria as a commercially available modified clay (Phoslock®). Althugh LS in natura released considerable amounts of phosphorus and did not present P adsorption capacity, it managed to adsorb some dissolved phosphorus after organic matter was removed through muffling. This study shows that LS is a cheap, feasible and environment-friendly alternative to be used as a management action in reservoirs undergoing blooms in the semiarid region of Brazil.

Thesis
1
  • JOÃO VITOR CAMPOS E SILVA
  • Participatory management on Amazon floodplains and its multi-trophic effects

  • Advisor : CARLOS AUGUSTO DA SILVA PERES
  • COMMITTEE MEMBERS :
  • ADRIANA ROSA CARVALHO
  • CARLOS ROBERTO SORENSEN DUTRA DA FONSECA
  • CECILIA IRENE PEREZ CALABUIG
  • EDUARDO MARTINS VENTICINQUE
  • RENATO CINTRA
  • Data: Jun 22, 2016


  • Show Abstract
  • freshwater systems represent the most threatened environments in the world, with considerably higher extinction rates than terrestrial environments. These systems can be described as social ecological systems where social, biological and biophysical relationships are complex and reciprocal. A good example of this complexity is in the Amazonian floodplains, where a high biological and ethnic diversity coexists. Establish effective conservation plans for the Amazon floodplains is a Homeric task, since the threats in these environments continues to grow. In the face of government failure in terms of financial and human resources, we argue that the inclusion of local communities in the conservation process can be an effective strategy. These community-based conservation schemes have been implemented in various ecosystems in the world, aimed at decentralization of conservation and empowerment of local communities. However, the global literature lacks studies evaluating the effects of these schemes in the light of the main objectives of the millennium: biodiversity conservation, poverty reduction and improving the quality of life of traditional communities. In this thesis we evaluated two solid community-based conservation systems in the Brazilian Amazon, the community management of the Arapaima and management of the Amazon turtle. Each chapter of this thesis brings a different approach to this problem. Finally, we conclude that Brazilian society is facing two very interesting models of conservation that still need adjustments, but have incredible potential to contribute to the conservation of floodplains and improve the quality of life of local communities.

2
  • TIEGO LUIZ DE ARAÚJO COSTA
  • Fire Ray II Project: Ecology and phylogeography of Dasyatis marianae Gomes, Rosa & Gadig 2000

  • Advisor : LIANA DE FIGUEIREDO MENDES
  • COMMITTEE MEMBERS :
  • HUGO BORNATOWSKI
  • LIANA DE FIGUEIREDO MENDES
  • MARIA LÚCIA GÓES DE ARAÚJO
  • RICARDO DE SOUZA ROSA
  • RODRIGO AUGUSTO TORRES
  • Data: Jun 27, 2016


  • Show Abstract
  • A large number of sharks and rays inhabit tropical coastal areas. Unlike pelagic environments in the open sea, coastal areas are more subject to variations, both by human actions such as the continental, geographic or climatic influence resulting in a wide variety of habitats. Some species may have close relationship with certain habitats as to be possible to distinguish specific standards for different locations. Dasyatis marianae is an endemic streak of northeastern Brazil, occurring from Maranhão to the south of Bahia, exclusively on the continental shelf. With a restricted distribution, this streak showed estenotópica, with low amplitude tolerance to environmental conditions, especially temperature, salinity and depth. As a result, D. marianae presented morphological, ecological and molecular differences intraspecific over their geographical distribution. The more lanes south of the distribution are larger and have a distinct morphometric standard against the rays of the northernmost locations. Also, they have a lower genetic diversity and a greater preference for crustaceans in their diet. In general, D. marianae is divided into two populations genetically structures, a large population connecting the extremes of the distribution and a more restricted population located in Salvador. local environmental characteristics insulate this population, even without a physical barrier easy to identify. The pattern of population structure of D. marianae suggests an isolation by environment (IBE) where the interaction between the species and the habitat structure their spatial variation, regardless of distance. This work, based on an integrative approach (morphology, feeding niche modeling and phylogeographical) certainly generates grants for management actions and conservation of this species, according to Ordinance No. 43/2014 MMA, is a priority for research on your conservation state.

3
  • BRUNNO FREIRE DANTAS DE OLIVEIRA
  • Macroecology and the conservation of multiple dimensions of biodiversity

  • Advisor : GABRIEL CORREA COSTA
  • COMMITTEE MEMBERS :
  • CARLOS ROBERTO SORENSEN DUTRA DA FONSECA
  • EDUARDO MARTINS VENTICINQUE
  • GABRIEL CORREA COSTA
  • MARCUS VINICUS CIANCIARUSO
  • MARILIA BRUZZI LION
  • Data: Jul 26, 2016


  • Show Abstract
  • Determining the mechanisms underlying spatial variation in biodiversity has long been the main challenge for ecologists and biogeographers. The past decade has seen a veritable explosion of studies documenting broad-scale spatial patterns in biodiversity. Nowadays, broad-scale patterns of species richness (SR) is well documented for several groups. However, biodiversity encompass variation in several aspects beyond SR, such as phylogenetic diversity (PD) and functional (or trait) diversity (FD). These dimensions have been argued to aid more powerful tests of biodiversity theories because they can capture the diversity of life better than simple measures of SR. Particularly important, the conservation of biodiversity and its multiple dimensions have been advocated as necessary to ensure the resilience of ecosystem services and maintain important evolutionary history. The present thesis is set on the interface between macroecology and biodiversity conservation, and uses integrated approaches that consider the connection between more than one dimension of biodiversity. In the first chapter, I we evaluate four prominent hypotheses which invoke either equilibrium (more individuals, niche diversity) or non-equilibrium dynamics (diversification rate, evolutionary time) to explain species richness and functional diversity of mammals worldwide. While equilibrium and non-equilibrium hypotheses have received considerable attention in the literature and some empirical support, it remains unknown whether they can explain the diversity of species and their traits alike. By integrating information on species richness and functional diversity, I address these issues and shed light on the mechanisms that generated the diversity of mammals and their life histories. The second chapter represents a database on natural history traits for amphibians worldwide: AmphiBIO. This database centralizes information on 19 traits related to ecology, morphology and reproduction features of amphibians. Data were assembled from more than 1,500 sources, and has potential to support a more comprehensive research in evolution, community ecology, biogeography and conservation of amphibians. The third chapter uses information from AmphiBIO to test the assumption that loss of PD is associated with loss of FD. We simulated species extinction scenarios based on IUCN criteria, calculated the loss of PD and FD, and verified the correlation. Analyzes were carried out across the complete amphibian tree and across worldwide amphibian assemblages. This study highlights for the possible negative consequences of local amphibians extinctions that may impact the continuous provision of ecosystem services. This thesis adds to better understand the mechanisms on the origination of global gradients of species diversity. Finally, I hope this thesis can be used to stimulate future studies on ecology and evolution, and support political decisions on minimizing the effects of projected species extinctions on biodiversity loss.

4
  • RICARDO ALMEIDA EMIDIO
  • Ecological-Behavioral&GIS Interface: instrumentals and cartography assessment and techniques solutions applied to generate Primatology’s cartography basis.

  • Advisor : ARRILTON ARAUJO DE SOUZA
  • COMMITTEE MEMBERS :
  • CARLOS ROBERTO SORENSEN DUTRA DA FONSECA
  • DIOGENES FELIX DA SILVA COSTA
  • JOSÉ EDUARDO MANTOVANI
  • MARIA ADELIA BORSTELMANN DE OLIVEIRA
  • SEBASTIAO MILTON PINHEIRO DA SILVA
  • Data: Aug 26, 2016


  • Show Abstract
  • The geographical spatial of organisms' behavioral interactions to ecological niche spatially structured (ecological background) provides a 'living' point of contact between Ecology and Evolution. The production of cartographic bases promoted by multidisciplinary interface between Ecology, Behavior & GIS, are motivating, opportune and challenging scenario. For Primatology, the challenges of the products derived from that interface are mostly linked to the trade-offs between data accuracy and field studies restrictions. In this view, it is demanded quality certification metrics formalizing indicators of potential discrepancies of landscape structure data (imaging products) and landscape function (animal positioning) capable of compromising ecological and behavioral patterns with spatial dependence. In order to meet these demands, this Thesis aims to promote to Primatology tools of accuracy assessment and quality cartographic databases derived from remote imaging and GNSS positioning. To achieve the objectives were developed: 1. Theoretical Review with integrative approach to the body of the Thesis; 2. Evaluation of geometric correction models for high spatial resolution remote sensing images; 3. Evaluation of bias at GNSS positioning methods in forested areas, and 4. Evaluation of cartographic scale magnitude by modeled cartography products. The results of geometric correction modeling of satellite imagesshowed that antagonic scenarios (Google Maps without geometric corrections - optimistic scenario 1 and Geoeye sensor with robust ortoretifitcation methodsconservative scenario 1) are statistically equivalent (Turkey HSD: p = 0.95) and feasibility at the same work scale: 1./25,000 B-class (PEC-PCD95%) which allows working within error limited between 7.5 to 12.5 m. The GNSS positioning metrics in forested areas assessment showed three different patterns: 1. Horizontal accuracy independent of methodological complexity; 2. RTK method ineffective; 3. Vertical Accuracy dependent on carrier waves. It was also observed that the positioning methods C / A code, autonomous, GPS, instant (optimistic scenario 2) and post-processing carrier waves (L1 and L2) GNSS (GPS and GLONASS), and modeling of mitigating the effects of multi path (Floodlight technology - Trimble®) withing acquisition times of up to 15’ (conservative scenario 2) have the same cartographic scale in planimetric axis: 1 / 25,000 B-class (PEC-PCD95%). It is observed that the quality of cartographic databases derived from remote imaging sensors is dependent on the quality control data (DEMs: spatial resolution, accuracy; GCPs: number, accuracy, spatial distribution), while the quality of positioning by GNSS in forested areas is a nebulous issue due determination of control data. The results of this thesis demonstrate feasibility of geometric modeling for high spatial resolution remote sensors at low cost and equivalence of quality positioning data for low complexity GNSS in forested area in planimetric axis. The thesis deepening discussions about relations costs / benefits of the presented instrumental solutions and potential applications for Ecology, Behavior & GIS interface. Finally, it is concluded that this Thesis contributes the following perspectives: i. Presents in depth and adjusted to the profile of readers of Ecology, Behavior and Primatology problematic as the absence of formal instruments of management of cartographic databases and data quality indicators in Ecology, Behavior & GIS interface as well as state of the art of this instrumental ensemble; ii. Formalizes and evaluates instrumental models of generation and correction of cartographic bases of imaging sensors high spatial resolution and positioning GNSS in forested areas; iii. Respond to trade-offs between quality and feasibility of cartographic products in Primatology through optimal cartographic scale formalized by the indicators of the magnitude of errors.

5
  • MARIA MARCOLINA LIMA CARDOSO
  • Omnivorous fish lifehistory and its implications for population and community dynamics in tropical lakes and reservoirs

  • Advisor : JOSE LUIZ DE ATTAYDE
  • COMMITTEE MEMBERS :
  • JOSE LUIZ DE ATTAYDE
  • RONALDO ANGELINI
  • VANESSA BECKER
  • GUSTAVO HENRIQUE GONZAGA DA SILVA
  • RODRIGO FERNANDES
  • Data: Aug 29, 2016


  • Show Abstract
  • Predation and competitive interactions are fundamentally dependent on body size. Higher variations in ingestion and metabolic rates occurs for different sizes for a same specie than among species. As well, ontogenetic niche shifts are common. However, only recently, intraspecific variation in body size has been included on studies of competition and predation. This thesis aims to understand the effects of sizeselective predation and intraspecific competition (different scales of foraging and metabolic costs by size) on sizestructure of omnivorous filterfeeding fish on tropics, i.e. Nile tilapia. The first chapter shows empirical results of sizeselective predation by piscivorous fish on Nile tilapia populations on Brasilian lakes and reservoirs. Nile tilapia shows a high mean adult size in the presence of piscivorous fish, and stunted populations in absence of predation. Effects of planktivory and omnivory for different sizes of a same species are show on second chapter. Our results reveals that populations dominated by adults have a stabilizing effect on plankton dynamic with nutrient enrichment, in contrast to population dominated by zooplanktivorous juveniles. The third chapter is a experimental model, where the physiological characteristics with body size of Nile tilapia were described and translated to population level. The model results shows that sizeselective mortality and resource availability for adult are the main factors driving Nile tilapia sizestructure. Higher adult sizes and lower fish biomass are found for high sizeselective mortality and low resource for adults. Only background mortality is not enough to build populations with large adult sizes. Even at high background mortality, the population is dominated by juveniles and small adult sizes. Our model sustain the empirical results of first chapter and indicates the main processes that drive Nile tilapia population dynamics, being a useful tool for management practices.

6
  • SILVANA MASCIADRI BÁLSAMO
  • Strategies to maximize conservation of biodiversity and ecosystem services in productive landscapes. Bringing ecology closer to territorial management.

  • Advisor : CARLOS ROBERTO SORENSEN DUTRA DA FONSECA
  • COMMITTEE MEMBERS :
  • CARLOS ROBERTO SORENSEN DUTRA DA FONSECA
  • ADRIANA ROSA CARVALHO
  • GISLENE MARIA DA SILVA GANADE
  • DEMETRIO LUIS GUADAGNIN
  • MARCEL ACHKAR
  • Data: Aug 29, 2016


  • Show Abstract
  • Strategies to maximize conservation of biodiversity and ecosystem services in productive landscapes. Bringing ecology closer to territorial management.

    Increased production and land use intensification is one of the most important pressures on ecosystems and their goods and services, with great impact in Latin America in recent decades. Appropriate land management policies to balance production landscapes with biodiversity conservation contribute to achieve the goals of development and sustainability, also top of agendas in all countries of the region. Easily applicable tools are needed to find ways of rural and urban sustainability in the political system.

    Canelones department surrounds Montevideo –Uruguay’s capital— and has the highest concentration of farming areas compared to other departments. Accordingly, it is one of the departments with the greatest impact on natural ecosystems, due to anthropic activities and population growth, currently higher than national average figures. A state of environmental warning and strong pressures and threats to biodiversity was recognized, which currently extinct, endangered, or vulnerable species and several types of contamination detected.

    The need to bring ecology closer to land management is a key to achieve a sustainable approach, and a great challenge to settle agricultural production with the conservation of biodiversity and associated ecosystem services (EESS). This thesis therefore proposed the following objectives: 1. Develop a territorial management model for Canelones that maximizes biodiversity conservation in production landscapes, addressing different landscape scales, and proposing appropriate environmental political and administrative management; 2. To investigate whether the productive land uses proposed by the Project AGUT: Fitness General Land Use (2010), are in accordance with the model 10:20:40:30 (Ch. 1), and if it is aligned with the objectives of sustainable development set out in the environmental agendas of the country; 3. Test if land surface of EESS mapped in Soutullo et al (2012) matches with the model, and estimate through the sale value of the land in the market, the cost to optimize the conservation of biodiversity and EESS in three scenarios: the model 10:20:40:30, AGUT (2010), and land surface of EESS of high conservation priority.

    Chapter 1 compared the current land uses (OPP 2010) with the model proposed by Smith et al. (2013), which suggests a general framework to maximize the retention of biodiversity in an agricultural landscape: the 10:20:40:30 guide. A GIS was elaborated offering tools to apply in land planning at Canelones, in landscapes scales defined by political management boundaries.

    The natural cover showed significant values lower the model, reflecting the pressure on natural ecosystems that exists in all landscape scales analyzed. The urgent challenge is increasing the natural soil surface. The potential management at different scales allows each locality to apply their strategies to recover natural soil, using natural parks, artificial lakes restoration, recuperation of riparian forests and wetlands. It also provides a planning framework for public and administrative policies.

    Chapter 2 compared productive land use projected by AGUT (2010) reclassified on intensive, moderate, low and natural, and test if it fits the model (Ch. 1). A GIS was developed as a tool for land planning. The results showed that the projection AGUT ensures no sustainability at all.

    The differences between both were significant, and the minimum of natural soil needed to promote conservation of biodiversity and associated EESS are not preserved. It would increase pressure on water resources and biological corridors of fluvial forest and riparian wetlands, intensifying land use in the entire territory, leading to a homogenization of the productive landscape through intensive and moderate land uses, and eliminating the possibilities of damping and environmental restoration, since no low land uses are proposed and natural cover

    is taken to a minimum. With this intensive productive landscape proposal, the objectives of productive and sustainable development posed by AGUT project would not be achieved, nor the guidelines to the same purpose planned by departmental guidelines in Canelones, and also is not in line with the national legislation or national and international agreements that Uruguay has assumed as environmental targets to be attained in the millennium development goals.

    Chapter 3 contrasted if the land area of EESS, with high priority conservation (Soutullo et al. 2012) matches the 10 % of natural cover of the model (Ch. 1). Moreover, through the market value of the land for sale, an assessment of costs was made to achieve the objectives of conservation and sustainability for Canelones, recovering it from the current scenario (Ch. 1), from AGUT (2010) (Ch. 2) and from EESS land cover. In the compared scenarios, at the departmental level, the EESS soil is greater (16,2%) than natural cover of the model (10%), although the results was wide-ranging in the other land scales analyzed. The 10% conservation of natural soil could arise as a conservation objective in the short and medium time. Moreover, reaching the EESS land cover could be a long-term goal, implementing management measures of that high priority surface to conserve. Economic valuation of natural cover of EESS provides opportunities to internalize and display costs in the economy. Indeed, cost estimates of achieving the objectives of 10% natural soil from the current scenario (OPP 2010), are less than the costs to get from the scenario posed by AGUT (2010), although higher are those to achieve the objectives of EESS land conservation.

    The balance between productive and sustainable systems, conservation of biodiversity and water resources of Canelones, should consider including more precisely in territorial policies a balance between them. The model 10:20:40:30 proposed an optimization of production and conservation objectives, ensuring minimal natural cover, and a percentage of buffer land cover, as moderate and low, to maintain connectivity and reduce fragmentation (Ch. 1). Analyzed landscape scales also offer opportunities in regional planning from different administrative areas, providing more variety of occasions for management of natural and cultural heritage of Canelones. Moreover, the academic and social scenario is very favorable, and although there are usage conflicts and anthropic impacts, society is increasingly receptive to environmental issues.

    Their participation is provided as fundamental and necessary to achieve sustainability goals in the long term.

7
  • UIRANDÉ OLIVEIRA COSTA
  • Litter decomposition: The role of  precipitation, solar radiation and  the effects of rainfall pattern in a changing climate  in an Brazilian Semi-Arid ecosystem

  • Advisor : ANDRE MEGALI AMADO
  • COMMITTEE MEMBERS :
  • ADRIANO CALIMAN FERREIRA DA SILVA
  • ALEXANDRE VASCONCELLOS
  • ANDRE MEGALI AMADO
  • JACOB SILVA SOUTO
  • JOSE LUIZ DE ATTAYDE
  • VIRGINIA FARIAS PEREIRA DE ARAUJO
  • Data: Aug 31, 2016


  • Show Abstract
  • The aim of this thesis is to understand the role of solar radiation and precipitation and their relationship with climate change on the control of decomposition in a Caatinga ecosystem in the Brazilian semiarid region. Through a set of manipulative field experiments, this thesis demonstrates that potodegradation (direct and indirect effects) affected the ecological process of decomposition, with a similar magnitude to the precipitation, in the studied area. We demonstrate an additive role of solar radiation and the precipitation in the control of annual decomposition rates and tends occurrence of synergism between these factors, at least part of the year. The results also prove that reductions in rainfall in climate change scenario for the region are responsible for to generate negative impacts on litter decay rates. We can conclude that the direct and indirect photodegradation ensures the presentation of higher levels and continue the process of decomposition of organic matter in the study area. Finally, this thesis alerts that a possible collapse of the litter decomposition process due to climate change may make vulnerable the functioning of this ecosystem.

8
  • CÍNTIA CARDOSO PINHEIRO
  • Morphological plasticity in trees and its application for the restoration of Caatinga

  • Advisor : GISLENE MARIA DA SILVA GANADE
  • COMMITTEE MEMBERS :
  • CARLOS ROBERTO SORENSEN DUTRA DA FONSECA
  • EDUARDO MARTINS VENTICINQUE
  • GISLENE MARIA DA SILVA GANADE
  • MARIA ROSA DARRIGO
  • MARILIA BRUZZI LION
  • Data: Sep 23, 2016


  • Show Abstract
  • A Plasticidade fenotípica em espécies de plantas tem se demonstrado um bom mecanismo para explicar parte da distribuição e ocorrência de espécies no planeta. Vários estudos vem sendo desenvolvidos para testar o papel da plasticidade em processos como invasão de espécies exóticas e expansão geográfica de espécies para locais heterogêneos, perturbados ou estressantes. Para tal, leva-se em consideração a capacidade de uma espécie em modificar suas estruturas frente à um ambiente independente do genótipo. Dentro do contexto da biologia do desenvolvimento, a literatura tem utilizado uma abordagem com linhagens de genótipos conhecidos, o que chamamos de plasticidade fenotípica strictu sensu. Por outro lado, estudos que tenham como foco aspectos ecológicos, tendem a assumir qualquer modificação do fenótipo frente a mudanças no recurso como plasticidade. Para esta abordagem ecológica, o termo utilizado é a Plasticidade fenotípica latu sensu, onde são incluídos e assumidos como mecanismos: normas de reação, variabilidade genética e a própria plasticidade strictu sensu, intra e inter específica. Neste caso específico, um bom delineamento na coleta de dados é fundamental para que não ocorra algum viés interpretativo. As características plásticas possuem uma grande importância adaptativa. Através delas é possível compreender quais estratégias morfológicas e fisiológicas permitem com que as plantas lidem com perturbações pontuais e com ambientes altamente estressantes. A compreensão destas estratégias pode trazer, além do melhor entendimento das comunidades naturais, uma ferramenta útil em programas de restauração. O semiárido brasileiro é um bioma altamente estressante, caracterizado por um forte filtro ambiental de estresse hídrico e altas temperaturas. Ademais, 53% de seu território já foi desmatado, e os métodos de restauração utilizados possuem baixa efetividade. A compreensão das estratégias de alocação de biomassa das plantas neste sistema é urgente para que esses métodos de restauração possam ser mais efetivos. Neste sentido, o primeiro capítulo desta tese busca compreender as possíveis relações entre padrões de plasticidade e a capacidade de espécies arbóreas serem bem sucedidas em programas de restauração. Pôde-se observar que espécies diferiram significativamente em sua capacidade plástica no que diz respeito à alocação de biomassa em raiz versus parte aérea. As espécies mais plásticas apresentaram em geral um maior potencial de sobrevivência em campo, demonstrando que a flexibilidade na alocação de biomassa, desempenha um importante papel em ambientes estressantes. Grime (1977) em seu trabalho clássico aponta 3 principais estratégias de captação e uso de recursos que plantas utilizam para lidar com diversas pressões ambientais: Ruderais, Competidoras e Estresse-tolerantes. Sabe-se que plantas Competidoras tendem a apresentar maior plasticidade fenotípica enquanto que em plantas Estresse-tolerantes a plasticidade é menos expressiva. Pouco se compreende sobre como estas estratégias de captação de recurso funcionam no semi-árido brasileiro. Da mesma forma, ainda permanece como uma lacuna entender se existe variação plástica das espécies com estratégias distintas em diferentes situações de disponibilidade de recurso. Por isto, no segundo capítulo buscou-se testar se características morfofuncionais dessas espécies vegetais estariam correlacionadas com suas estratégias de resposta à seca e se espécies arbóreas diferem nas suas estratégias de alocação em raíz e parte aérea quando enfrentam situações de estresse hídrico. Espera-se que as espécies “Competidoras” tendam a apresentar maior capacidade de realocação de biomassa frente as alterações abióticas do que as espécies com características “Estresse-tolerantes”. As estratégias de crescimento e alocação em raiz e parte aérea das espécies lenhosas estudadas diferiram de acordo com as disponibilidades de recursos. Algumas espécies apresentaram respostas de maior acúmulo de biomassa em raíz em relação à parte aérea quando irrigadas, outras apresentaram maior investimento em biomassa em raiz quando em tratamentos de seca. Em geral, a relação do investimento em raíz e parte aérea não demonstrou estar correlacionadas com características morfofuncionais de altura, SLA e densidade de madeira, no entanto, árvores mais altas se mostraram mais propensas a alongarem suas raízes em situações de seca. A diversidade de estratégias que possuem as espécies da Caatinga pode ser atribuída aos seus diferentes históricos de pressões, aliado ao filtro ambiental que a Caatinga exerce, modulando um grupo de estratégias que não podem ser completamente explicadas pelo modelo do triângulo do Grime (1977). A compreensão em larga escala de como os tipos de plasticidades morfológicas e fisiológicas e de parte aérea e raiz variam de acordo com fatores abióticos ainda não é clara. Por isto, no terceiro capítulo testamos se espécies que apresentam maior plasticidade fisiológica apresentam também maior plasticidade morfológica, se plantas são mais plásticas em atributos fisiológicos ou morfológicos e se o tipo de recurso disponível, seja este acima ou abaixo do solo poderia influenciar diferencialmente a plasticidade de alocação em raiz e parte aérea. Vimos que de modo geral não há diferença entre investimento de plasticidade entre atributos fisiológicos e morfológicos. Pode-se também verificar que existe diferença nos níveis de plasticidade entre espécies, porém aquelas que são mais plásticas em atributos morfológicos também o são em atributos fisiológicos. Adicionalmente, verificou-se que a alteração de um recurso de solo como água e nutrientes leva a uma maior alocação em raízes, enquanto que a alteração em recursos acima do solo como luz e CO2 leva a uma maior alocação de biomassa em folhas e galhos. Esses resultados demonstram que plantas não só diferem em sua capacidade de serem plásticas frente às alterações ambientais, mas que também o seu maquinário fisiológico e morfológico evolui conjuntamente para expressar características plásticas. Adicionalmente, a plasticidade em plantas é usada como um meio de intensificar a captura de um recurso quando este se torna disponível.  

9
  • BERNARDO MONTEIRO FLORES
  • Resilience of Amazonian forests: The roles of fire, flooding and climate

  • Advisor : JOSE LUIZ DE ATTAYDE
  • COMMITTEE MEMBERS :
  • JOSE LUIZ DE ATTAYDE
  • CARLOS ROBERTO SORENSEN DUTRA DA FONSECA
  • EDUARDO MARTINS VENTICINQUE
  • FELIPE PIMENTEL LOPES DE MELO
  • MARINA HIROTA
  • Data: Sep 30, 2016


  • Show Abstract
  • The Amazon has recently been portrayed as a resilient forest system based on quick recovery of biomass after human disturbance. Yet with climate change, the frequency of droughts and wildfires may increase, implying that parts of this massive forest may shift into a savanna state. Although the Amazon basin seems quite homogeneous, 14% is seasonally inundated. In my thesis I combine analyses of satellite data with field measurements and experiments to assess the role of floodplain ecosystems in shaping the resilience of Amazonian forests. First, I analyse tree cover distribution for the whole Amazon to reveal that savannas are relatively more common on floodplains. This suggests that compared to uplands, floodplains spend more time in the savanna state.

    Also, floodplain forests seem to have a tipping point at 1500 mm of annual rainfall in which forests may shift to savanna, whereas the tipping point for upland forests seems to be at 1000 mm of rainfall. Combining satellite and field measurements, I show that the higher frequency of savannas on floodplain ecosystems may be due to a higher sensitivity to fire. After a forest fire, floodplains lose more tree cover and soil fertility, and recover more slowly than uplands (chapter 2). In floodplains of the Negro river, I studied the recovery of blackwater forests after repeated fires, using field data on tree basal area, species richness, seed availability, and herbaceous cover. Results indicate that repeated fires may easily trap blackwater floodplains in an open-vegetation state, due the sudden loss of forest resilience after a second fire event (chapter 3). Analyses of the soil and tree composition of burnt floodplain forests, reveal that a first fire is the onset of the loss of soil fertility that intensifies while savanna trees dominate the tree community. A tree compositional shift happens within four decades, possibly accelerated by fast nutrient leaching. The rapid savannization of floodplain forests after fire implies that certain mechanisms such as environmental filtering may favour the recruitment of savanna trees over forest trees (chapter 4). In chapter 5, I experimentally tested in the field the roles of dispersal limitation, and environmental filtering for tree recruitment in burnt floodplain forests. I combine inventories of seed availability in burnt sites with experiments using planted seeds and seedlings of six floodplain treespecies. Repeated fires strongly reduce the availability of tree seeds, yet planted trees thrive despite degraded soils and high herbaceous cover. Moreover, degraded soils on twice burnt sites seem to limit the growth of most pioneer trees, but not of savanna trees with deeper roots. Our results suggest a limitation of forest trees to disperse into open burnt sites. The combined evidence presented in this thesis support the hypothesis that Amazonian forests on floodplains are less resilient than forests on uplands and more likely to shift into a savanna state. The lower ability of floodplains to retain soil fertility and recover forest structure after fire may accelerate the transition to savanna. I also present some evidence of dispersal limitation of floodplain forest trees. Broad-scale analyses of tree cover as a function of rainfall suggest that savannas are likely to expand first in floodplains if Amazonian climate becomes drier. Savanna expansion through floodplain ecosystems to the core of the Amazon may spread fragility from an unsuspected place.

2015
Dissertations
1
  • Natalia de Medeiros Pires
  • Economy of the island of eco-tourism: the role of shark-diving and shark harvesting.

  • Advisor : ADRIANA ROSA CARVALHO
  • COMMITTEE MEMBERS :
  • ADRIANA ROSA CARVALHO
  • EDUARDO MARTINS VENTICINQUE
  • RAFAEL DETTOGNI GUARIENTO
  • Data: Feb 24, 2015


  • Show Abstract
  • Beyond its importance in maintaining ecosystems, sharks provide services that play important socioeconomic roles. The rise in their exploitation as a tourism resource in recent years has highlighted economic potential of non-destructive uses of sharks and the extent of economic losses associated to declines in their population. In this work, we present estimates for use value of sharks in Fernando de Noronha Island - the only ecotouristic site offering shark diving experience in the Atlantic coast of South America. Through the Travel Cost Method we estimate the total touristic use value aggregated to Noronha Island by the travel cost was up to USD 312 million annually, of which USD 91.1 million are transferred to the local economy. Interviewing people from five different economic sectors, we show shark-diving contribute with USD 2.5 million per year to Noronha’s economy, representing 19% of the island’s GDP. Shark-diving provides USD 128.5 thousand of income to employed islanders, USD 72.6 thousand to government in taxes and USD 5.3 thousand to fishers due to the increase in fish consumption demanded by shark divers. We discover, though, that fishers who actually are still involved in shark fishing earn more by catching sharks than selling other fish for consumption by shark divers.  We conclude, however, that the non-consumptive use of sharks is most likely to benefit large number of people by generating and money flow if compared to the shark fishing, providing economic arguments to promote the conservation of these species.

2
  • NATÁLIA CARVALHO ROOS
  • ecological knowledge of fishermen and the current state of artisanal fishing parrotfish (Perciformes: Scaridae) in APA Coral Reef - RN.

  • Advisor : ADRIANA ROSA CARVALHO
  • COMMITTEE MEMBERS :
  • ADRIANA ROSA CARVALHO
  • ALEXANDRE FADIGAS DE SOUZA
  • RAFAEL DETTOGNI GUARIENTO
  • Data: Feb 26, 2015


  • Show Abstract
  • Sustainably manage the local fishing small-scale coral reefs is challenging because of its great importance to local communities. The reef fish are considered an important source of food and income for coastal human populations, furthermore, they perform vital ecosystem functions for the maintenance of coral reefs. The parrotfish (Perciformes: Scaridae) are currently one of most reef fish caught by artisanal fishing in Rio Grande do Norte. Considered large herbivores have a huge practical importance for as coral algae growth control and prevent dominance of superior competing species by keeping the diversity of reefs. By consuming a large proportion of algae, these fish are the most energy transfer link for higher trophic levels. However, the lack of information about other aspects of the biology and ecology of these fish is still large in Brazil, and especially the lack of data capture through fishing and its impacts on the reefs, making it harder to manage. It is known that studies using the ecological knowledge of fishermen (CEP) on fish species complement the data from the scientific literature and are fundamental to the design of management plans. Thus, to obtain data ecological knowledge and understand the fishermen's behavior are key components for effective fisheries management, particularly in cases where there is lack of information. Thus, the aim of this study is to use the local ecological knowledge of fishermen and landing data for information on the parrotfish species and diagnose the current state and the dynamics of this type of fishing in Recife PAC Rio Grande do Norte (APARC - RN).

3
  • VANESSA RODRIGUES DE MORAIS
  • Finding the way home: movement of butterflies in non-familiar habitats

  • Advisor : MARCIO ZIKAN CARDOSO
  • COMMITTEE MEMBERS :
  • ARRILTON ARAUJO DE SOUZA
  • MARCIO ZIKAN CARDOSO
  • MARCUS VINICIUS VIEIRA
  • Data: Feb 26, 2015


  • Show Abstract
  • Natural landscapes have been dramatically affected by habitat loss and fragmentation, which transform continuous forest in habitat patches imbedded in areas of non-habitat (matrices). This matrices, inhospitable or not, affect countless ecological process, like dispersal. One of the ways to understand this effect of matrix on dispersal is studying animal’s perceptual range. Which is a range at which an animal perceive landscape elements. This perception is directly connected to the success to reach a new habitat patch while animals navigate through matrix. To contribute to this knowledge we evaluate the habitat perception of Heliconius erato. However, we were also interest in evaluate the effect of butterflies age and matrix type on its perception. Consequently, we raised butterflies on laboratory and matched with butterflies from forest during a release experiment. To determinate perceptual range, we did releases in two different matrices at three distances from forest (0, 30 and 100 meters) and measured the final angle reached for butterflies. We found that: I) butterflies released in edge were strongly oriented to forest; II) than higher the release distance the lower perceptual ability and III) there is an interaction between age and matrix type. Naïve butterflies oriented better on open field (perceptual range: 30-100 meters and experienced oriented better at coconut plantation (perceptual range: 30-100 meters).

4
  • FELIPE PEREIRA MARINHO
  • Land use in semiarid environments: effects on vegetation’s structure and interactions among plants in a dry tropical forest

  • Advisor : GISLENE MARIA DA SILVA GANADE
  • COMMITTEE MEMBERS :
  • ALEXANDRE FADIGAS DE SOUZA
  • GISLENE MARIA DA SILVA GANADE
  • JOSÉ ALVES DE SIQUEIRA FILHO
  • Data: Feb 27, 2015


  • Show Abstract
  • Land use is the main driver of vegetation changes worldwide and its long-lasting effect is critical in arid and semi-arid systems. Brazilian Caatinga is one of the species-richest semiarid biomes of the world and is threatened by strong land use pressure and poor protection. Land use in Caatinga mainly comprises grazing by cattle, donkeys, goats or horses, and wood extraction for construction work and charcoal production. In this study, we investigate the effects of past and present land use on plant community richness and structure. We used LANDSAT and GEOEYE satellite information to identify Caatinga forest areas with and without past vegetation clearing. We also quantified current land use, measured as the degree of grazing and wood extraction. We then assessed current vegetation structure, in particular vegetation cover, height, basal area for shrubs and trees, and seedling recruitment. The association between past vegetation clearing and strong present grazing showed a compelling negative effect on vegetation structure, increasing the proportion of bare ground. We suggest that land use planning projects in semi-arid systems should avoid grazing in areas that suffered past clear-cut. This simple land use technique should help to prevent processes of land impoverishment and desertification in semi-arid systems.

5
  • ANANDA DE OLIVEIRA DA SILVA
  • Pistas visuais no reconhecimento intra e interespecífico em duas borboletas miméticas

  • Advisor : MARCIO ZIKAN CARDOSO
  • COMMITTEE MEMBERS :
  • MARCIO ZIKAN CARDOSO
  • ARRILTON ARAUJO DE SOUZA
  • ALDO MELLENDER DE ARAÚJO
  • Data: Mar 13, 2015


  • Show Abstract
  • Duas espécies de borboletas miméticas Heliconius erato e Heliconius melpomene apresentam coloração similar. Tal similaridade pode atuar confundindo o reconhecimento de seus co-específicos no momento da escolha de parceiros sexuais. As duas espécies possuem um conjunto de variações sutis na cor de suas asas que são  compartilhadas por ambas espécies, como os pontos vermelhos encontrados acima da faixa amarela. Em H. erato variações na cor de suas asas são exclusivas da espécie como os red raylets e pontos amarelos na região distal da asa posterior.  Acredita-se que tais variações fenotípicas auxiliem no reconhecimento de seus co-específicos, para tanto, o presente estudo tem por intuito verificar se as duas espécies envolvidas na análise reconhecem seus co-específicos. Sendo, experimentos com modelos que contemplaram  variações sutis foram montados e apresentados aos machos de H. erato e H. melpomene. Em cada experimento foi verificado a probabilidade relativa de aproximação do macho ao modelo. O teste de likelihood indicou que as diferenças sutis encontradas nos padrões de asas de H. erato e H. melpomene podem atuar como pistas de reconhecimento de indivíduos da mesma espécie. Sendo que a espécie H. erato pode ser considerando um discriminador mais refinado no reconhecimento e ambas as espécies selecionaram modelos que possuem variações médias, indicando seleção normalizadora para a escolha do padrão de asa. Podemos concluir, que a cor e, principalmente, os padrões sutis na variação da cor são utilizados como um sinal usado por borboletas no reconhecimento de seus co-específicos.

6
  • DAMIÃO VALDENOR DE OLIVEIRA
  • BIOLOGIA REPRODUTIVA DE MIMUS GILVUS (AVES: MIMIDAE) EM ÁREA DE RESTIGA NO NORDESTE DO BRASIL

  • Advisor : MAURO PICHORIM
  • COMMITTEE MEMBERS :
  • EDUARDO MARTINS VENTICINQUE
  • MARCIO ZIKAN CARDOSO
  • RACHEL MARIA DE LYRA NEVES
  • Data: Apr 14, 2015


  • Show Abstract
  • O sabiá da praia, Mimus gilvus (Aves: Mimidae) é um passeriforme com ampla distribuição na América Central e do Sul. No Brasil ocorre principalmente nas áreas de restinga e vegetação próxima a praia. Muitos atributos de sua biologia reprodutiva são desconhecidos, principalmente em relação ao sucesso reprodutivo. Nesse sentido, durante os anos de 2010-2011, 2011-2012 e 2014-2015 foram feitas visitas à área de restinga no Centro de Lançamento da Barreira do Inferno (CLBI), localizado entre os municípios de Natal e Parnamirim-RN (5°54’S e 35°10’W), onde foram feitas buscas sistemáticas buscando descrever características da biologia reprodutiva de M. gilvus, estimar o seu sucesso reprodutivo utilizando o método de Mayfield, e identificar os principais fatores que influenciam o seu sucesso reprodutivo em ambiente de restinga. Para isso, foram utilizados 45 ninhos ativos monitorados. Apenas durante a temporada reprodutiva de 2011-2012 e 2014-2015 foram feitas visitas sistemáticas a área de estudo. O período reprodutivo variou de agosto a março. O tamanho da ninhada variou de dois, três e seis ovos (n = 22). Ninhadas de dois ovos foram mais frequentes, sendo a média de ovos colocados por ninho de 2 ± 0,51 (n = 20 ninhos). O período de incubação foi de aproximadamente 13 ± 1,9 dias (n = 11 ninhos ). O período de permanência dos filhotes no ninho foi de aproximadamente 11 ± 1,6 dias (n = 9 ninhos). O sucesso aparente foi de 37,8% e o sucesso estimado pelo método de Mayfield foi de 26,6 %. A predação foi a principal causa da perda de ninhos na área de estudo. As taxas de sobrevivência diária (TSD) obtidas foram 0,9593 para o período de incubação e 0,9313 para o período de ninhego. As estimativas de sobrevivência para cada período foram 0,5827 para incubação e 0,4571 para ninhego respectivamente. A precipitação média acumulada para cada mês influenciou negativamente as taxas de eclosão dos ninhos de M. gilvus. Além disso, o número de eclosões entre o período mais chuvoso (estação chuvosa) e o período de menor precipitação (estação seca) foram diferentes. O número de ninhos perdidos de M. gilvus foi menor em moitas do que em cactos, o que pode justificar o maior número de ninhos dessa espécie encontrados em moitas. As taxas de sobrevivência no período de ninhego foram menores em comparação com o período de incubação. M. gilvus parece evitar o período mais chuvoso durante sua reprodução, concentrado a maior parte de seus ninhos no período de menor precipitação.

7
  • PAULO HENRIQUE DANTAS MARINHO
  • Gato-do-mato-pequeno (Leopardus tigrinus) na Caatinga: Ocupação e padrão de atividade de um felídeo ameaçado e pouco conhecido na floresta tropical seca do nordeste do Brasil.

  • Advisor : EDUARDO MARTINS VENTICINQUE
  • COMMITTEE MEMBERS :
  • EDUARDO MARTINS VENTICINQUE
  • MIRIAM PLAZA PINTO
  • SAMUEL ENRIQUE ASTETE PEREZ
  • Data: Apr 30, 2015


  • Show Abstract
  • Ao passo que os carnívoros são considerados importantes regulares e estruturadores das comunidades naturais, também são extremamente pressionados pela ação antrópica. Ameaçado de extinção, o gato-do-mato-pequeno (Leopardus tigrinus) é uma das espécies menos conhecidas entre os felinos neotropicais. Neste trabalho, investigamos a ocupação e o padrão de atividade de L. tigrinus na Caatinga, tentando entender que fatores ambientais e antrópicos afetam essa ocupação e como o padrão de atividade da espécie pode ser influenciado por fatores bióticos e abióticos. Para isso levantamos dados de ocorrência e do horário de atividade da espécie em 10 áreas espalhadas pelo estado do Rio Grande do Norte. Para modelar a ocupação, utilizamos modelos hierárquicos baseados em máxima verossimilhança que representaram hipóteses biológicas e foram ranqueados com o uso do Critério de Informação de Akaike (AIC). De acordo com os resultados, a ocorrência da espécie é maior distante de assentamentos rurais e em locais com maior proporção de vegetação arbórea. Desta forma, L. tigrinus parece ser afetado negativamente pela atividade antrópica existente nesses assentamentos e demonstra uma preferência por áreas do habitat com vegetação estruturalmente mais complexa. Analisando os horários dos registros da espécie através de estatística circular, concluímos que o seu padrão de atividade é majoritariamente noturno. Dentre os fatores testados, a atividade de L. tigrinus foi diretamente afetada pela disponibilidade de pequenos mamíferos terrestres, provavelmente, suas presas preferenciais neste ecossistema. Além disso, as temperaturas registradas no ambiente afetaram direta e indiretamente a atividade da espécie, já que também condicionam a atividade das suas presas. Os resultados encontrados nesta pesquisa melhoram o conhecimento sobre um felino ameaçado que habita a Caatinga, podendo assim auxiliar no desenvolvimento de estratégias de conservação e manejo da espécie, bem como no planejamento de pesquisas futuras neste ecossistema.

8
  • GUSTAVO GIRÃO BRAGA
  • INFLUÊNCIA DA SECA EXTREMA NA DINÂMICA FITOPLANCTÔNICA DE UM RESERVATÓRIO DA REGIÃO TROPICAL SEMIÁRIDA: UMA ABORDAGEM MORFO-FUNCIONAL

  • Advisor : VANESSA BECKER
  • COMMITTEE MEMBERS :
  • LUCIA HELENA SAMPAIO DA SILVA
  • ODETE ROCHA
  • VANESSA BECKER
  • Data: May 12, 2015


  • Show Abstract
  • As secas são fenômenos climáticos que têm ocorrido com maior frequência nas últimas décadas e comprometem o fornecimento de água potável em regiões semiáridas. A escassez de chuvas aliada às altas taxas de evaporação nessas regiões causam reduções significativas nos volumes dos reservatórios. Essas condições, por sua vez, favorecem a concentração de nutrientes e o crescimento excessivo da biomassa fitoplanctônica que inclui florações de cianobactérias potencialmente tóxicas. Portanto, há uma tendência de que o processo de eutrofização se intensifique nesses reservatórios de durante períodos de seca. A comunidade fitoplanctônica é capaz de responder rapidamente às mudanças ambientais relacionadas à disponibilidade de nutrientes e luz, por meio de sua biomassa e composição, sendo considerado como um bom preditor das variáveis ambientais. O objetivo desse estudo foi avaliar a influência de um período de seca extrema sobre a disponibilidade de luz, nutrientes e sobre a biomassa fitoplanctônica, utilizando duas abordagens funcionais (Grupos Funcionais de Reynolds e Grupos Morfo-funcionais de Kruk) em um reservatório da região semiárida brasileira. Além disso, buscou-se comparar qual das abordagens melhor explicou tais mudanças ambientais. No presente estudo, foi constatado que a redução de 90% do volume do reservatório, em conjunto com a redução da luminosidade e o aumento da disponibilidade de nutrientes, promove um aumento da biomassa algal. Os resultados das análises multivariadas utilizando ambas as abordagens funcionais diferenciaram as amostras dos períodos de volumes altos e volumes baixos, sendo a luminosidade e os nutrientes as principais variáveis ambientais que melhor explicaram a associação dos grupos funcionais. A comunidade fitoplanctônica sofreu mudanças em sua composição funcional inicial, caracterizada por organismos típicos de ambientes meso-eutróficos (grupos F e J), para organismos descritores de ambientes eutrofizados e túrbidos (SN, S1 e III e VII). A abordagem que mais explicou a variação dos dados foi a Morfo-Funcional, porém, apresentou menor sensibilidade em detectar a contribuição do grupo IV em condições de maior luminosidade. A abordagem de grupos funcionais de Reynolds descreveu de maneira mais detalhada a dinâmica fitoplanctônica associada à redução do volume.

9
  • ALAN FILIPE DE SOUZA OLIVEIRA
  • Influência Estrutural da Paisagem e do Microhabitat na Diversidade de Lagartos em Áreas de Caatinga do Rio Grande do Norte

  • Advisor : ADRIAN ANTONIO GARDA
  • COMMITTEE MEMBERS :
  • ADRIAN ANTONIO GARDA
  • DANIEL OLIVEIRA MESQUITA
  • FREDERICO GUSTAVO RODRIGUES FRANÇA
  • Data: May 27, 2015


  • Show Abstract
  • Abundância e riqueza de espécies são parâmetros centrais para ecologia e cruciais para medidas de diversidade e composição de espécies em um ambiente. Podem ser afetados pelas alterações, pela estrutura da paisagem e do habitat, que repercutem de maneira distinta entre os grupos taxonômicos promovendo perda de diversidade. Portanto, entender como esses padrões ocorrem é imprescindível para possíveis decisões sobre a conservação dessas espécies e seus ambientes. Diante disso, este trabalho objetivou avaliar a influência da alteração e estrutura da paisagem e do habitat sobre os lagartos com ênfase na Caatinga. Para isso, foram amostradas durante três meses sete áreas de Caatinga através do método de encontro visual por transectos. Ainda, variáveis da paisagem e do habitat foram registradas para avaliar como elas influenciam esse grupo neste ambiente, através da seleção de modelos. Nossos resultados demonstraram que a riqueza de espécies foi afetada pela complexidade topográfica de maneira positiva, assim como pela quantidade de afloramento rochoso. Este último também foi responsável por agrupar as áreas amostrais em três grupos dissimilares em relação à composição de espécies. A complexidade topográfica e o número de afloramentos rochosos afetam a riqueza de espécies de maneira positiva, devido à heterogeneidade ambiental que elas promovem no ambiente, permitindo as espécies refúgios, abrigos e locais para termorregulação. Além disso, áreas mais complexas topograficamente são menos suscetíveis às alterações e mais preservadas, apresentando maior diversidade. A composição de espécies, como registrado em outros ambientes, teve a estrutura do habitat como principal fator em agrupar as áreas amostradas. Isso corrobora nossa hipótese de que ela, através da heterogeneidade ambiental afeta os parâmetros de riqueza e abundância das espécies. Portanto, preservar esses ambientes através de unidades de conservação e de um zoneamento do uso da terra é de extrema importância para a manutenção da diversidade dos lagartos na Caatinga.

10
  • KIONARA SARABELLA TURIBIO E SILVA
  • FORECAST DECREASE IN VEGETATION GREENNESS UNDER CLIMATE CHANGE IN THE BRAZILIAN CAATINGA

  • Advisor : ADRIANA MONTEIRO DE ALMEIDA
  • COMMITTEE MEMBERS :
  • ADRIANA MONTEIRO DE ALMEIDA
  • EDUARDO MARTINS VENTICINQUE
  • THIAGO SANNA FREIRE SILVA
  • Data: Jun 15, 2015


  • Show Abstract
  • -

11
  • LARISSA NASCIMENTO DOS SANTOS SILVA
  • Borboletas no semiárido: sazonalidade e padrões de diversidade de borboletas frugívoras em um ambiente extremo

  • Advisor : MARCIO ZIKAN CARDOSO
  • COMMITTEE MEMBERS :
  • ALEXANDRE FADIGAS DE SOUZA
  • MARCIO ZIKAN CARDOSO
  • ONILDO JOÃO MARINI FILHO
  • Data: Jun 19, 2015


  • Show Abstract
  • Comunidade de borboletas frugívoras na caatinga: padrões de diversidade e sazonalidade

     
    A distribuição espaço-temporal das populações reflete o ajuste de suas características biológicas às condições ambientais e interações bióticas, conforme elementos precursores adaptativos e filogenéticos. Estações climáticas alternadas tendem a refletir padrões sazonais de atividade dos organismos e de diversidade de espécies. Porém, esses padrões em comunidades de borboletas em ambientes secos ainda não são claros. Estudamos uma comunidade de borboletas frugívoras na ESEC Seridó, no nordeste do Brasil, com o intuito de caracterizar a guilda no semiárido e verificar a contribuição relativa de variáveis climáticas e vegetacionais sobre a sua composição, diversidade e fenofaunística. As borboletas foram amostradas mensalmente, durante um ano, e a distribuição das espécies foi associada às características estruturais de fitofisionomias (ex. riqueza e abundância de espécies arbóreo-arbustivas, cobertura de dossel, cobertura de herbáceas, serapilheira) e a dados climatológicos (temperatura, pluviosidade e umidade). Foram capturados 9580 indivíduos de 16 espécies de borboletas, pertencentes a quatro subfamílias (Biblidinae, Charaxinae, Nymphalinae e Satyrinae). A riqueza, abundância e diversidade variaram em diferentes escalas de tempo e espaço, sendo maiores na estação chuvosa, enquanto a β-diversidade e turnover foram maiores na seca. A distribuição das espécies seguiu principalmente as mudanças de umidade, pluviosidade e fenologia vegetacional, havendo nicho compartilhado dentro de subfamílias. Os diferentes táxons devem ter resposta distinta aos estímulos ambientais, como também responder à fenologia de hospedeiras e ter estratégias de reprodução distintas. Havendo inclusive, indícios de adaptações fisiológicas e comportamentais como reprodução sazonal e estivação. Então, entendendo como a sazonalidade climática e vegetacional interagem no controle de comunidades de borboletas é possível melhor compreender a sua dinâmica espaço-temporal e evolução ecológica. Além de dar suporte ao biomonitoramento e conservação de áreas preservadas, sobretudo em ambientes sob pressão antrópica e de condições ambientais extremas como o semiárido.
12
  • DANIEL BEZERRA DE MELLO
  • Áreas importantes para a conservação do último grande herbívoro da Caatinga Potiguar: O veado-catingueiro (Mazama gouazoubira)

  • Advisor : EDUARDO MARTINS VENTICINQUE
  • COMMITTEE MEMBERS :
  • EDUARDO MARTINS VENTICINQUE
  • MARCIO ZIKAN CARDOSO
  • RENATA SANTORO DE SOUSA LIMA
  • Data: Jun 23, 2015


  • Show Abstract
  • Cervídeo Mazama gouazoubira é a espécie de veado que possui maior distribuição dentre as espécies sul americanas. Aspectos da vegetação, predação, competição, caça e perda de habitat são fatores importantes para compreender a distribuição espacial de herbívoros na paisagem. Dessa forma, considerando a falta de estudos de mamíferos de médio e grande porte na Caatinga, objetivamos compreender quais os fatores ambientais e antrópicos que influenciam a ocupação do veado-catingueiro (M. gouazoubira) na região semiárida do estado do Rio Grande do Norte, Brasil. O estudo foi realizado em 10 áreas amostrais e utilizamos armadilhas fotográficas para amostragem e modelos de ocupação foram construídos representando nossas hipóteses biológicas. Os modelos foram ranqueados através dos valores obtidos do AIC. As variáveis cobertura vegetal de caatinga e densidade da vegetação mostraram maior efeito, já a caatinga arbórea mostrou um efeito menor, sugerindo que a espécie é altamente dependente da vegetação para ocorrer, possuindo menor dependência de caatinga arbórea. Esperamos que nossos resultados possam ser utilizados como suporte para planos de manejo e criação de novas unidades de conservação no estado.

13
  • THAISA ACCIOLY DE SOUZA
  • DISTRIBUIÇÃO E USO DE HABITAT POR PEIXES RECIFAIS EM UM GRADIENTE AMBIENTAL: ESTUDO DE CASO EM RECIFES ARENÍTICOS

  • Advisor : LIANA DE FIGUEIREDO MENDES
  • COMMITTEE MEMBERS :
  • FULVIO AURELIO DE MORAIS FREIRE
  • JOSE GARCIA JUNIOR
  • LIANA DE FIGUEIREDO MENDES
  • Data: Jul 3, 2015


  • Show Abstract
  • Há diversos fatores abióticos relatados na literatura como reguladores da distribuição das espécies de peixes em ambientes marinhos. Dentre eles, destacam-se complexidade estrutural do hábitat, composição bentônica, profundidade e distância da costa, comumente relatadas como influenciadores positivos na diversidade de diferentes espécies, incluindo os peixes recifais. Estes são elementos dominantes em sistemas recifais e considerados de elevada importância ecológica e socioeconômica. A compreensão de como os fatores supracitados influenciam na distribuição e uso de habitat das comunidades de peixes recifais tornam-se importantes para seu manejo e conservação. Assim, o presente trabalho pretende avaliar a influencia destas variáveis sobre a comunidade de peixes recifais ao longo de um gradiente ambiental de profundidade e distancia da costa em recifes de base arenítica na costa do Rio Grande do Norte. Tais variáveis também serão utilizadas para a criação de um modelo preditivo simples da biomassa de peixes recifais para o ambiente estudado. A coleta de dados foi realizada por meio de censos visuais in situ, sendo registrados dados ambientais (complexidade estrutural do hábitat, tipo de cobertura do substrato, megafauna de invertebrados bentônicos) e ecológicos (riqueza, abundancia e classes de tamanho dos peixes recifais). Como complemento, informações sobre a dieta foram levantadas através de literatura e a biomassa foi estimada a partir da relação peso-comprimento de cada espécie. No geral, os recifes apresentaram uma baixa cobertura por corais, sendo os recifes Rasos, Intermediários I e II dominados por algas e os Fundos por algas e esponjas. A complexidade aumentou ao longo do gradiente e influenciou positivamente na riqueza e abundancia de espécies. Ambos atributos influenciaram a estruturação da comunidade de peixes recifais, incrementando a riqueza, abundancia e biomassa dos peixes, bem como diferenciando a estruturação trófica da comunidade ao longo do gradiente de profundidade e distancia da costa. A distribuição e utilização do hábitat pelos peixes recifas foi associada a disponibilidade de alimentos. O modelo preditor identificou a profundidade, rugosidade e a cobertura por algas folhosas, algas calcárias e corais moles como as variáveis mais significativas influenciando a biomassa de peixes recifais. Em suma, a descrição e o entendimento destes padrões são passos importantes para elucidação dos processos ecológicos. Neste sentido, nossa abordagem fornece um novo entendimento da estruturação da comunidade de peixes recifais do Rio Grande do Norte, permitindo entender uma parte de um todo e auxiliar futuras ações de monitoramento, avaliações, manejo e conservação destes e outros recifes do Brasil.

14
  • IAGE TERRA GUEDES DE OLIVEIRA
  • REGULAÇÃO DO METABOLISMO BACTERIANO EM DOIS RESERVATÓRIOS OLIGO-MESOTRÓFICOS DO SEMIÁRIDO TROPICAL

  • Advisor : ANDRE MEGALI AMADO
  • COMMITTEE MEMBERS :
  • ANDRE MEGALI AMADO
  • GUSTAVO HENRIQUE GONZAGA DA SILVA
  • NG HAIG THEY
  • Data: Aug 31, 2015


  • Show Abstract
  • Os ecossistemas de água doce tem um importante papel na ciclagem global de carbono, uma vez que recebem cerca de 2,9 Pg C ano-1 advindo dos ecossistemas terrestres, processando e/ou estocando até 2,6 Pg C ano-1.Desses, até 2,1 Pg C ano-1 são mineralizados na coluna d’água em grande parte pelas bactérias planctônicas. Essas são os organismos planctônicos mais numerosos nos ecossistemas aquáticos continentais, por isso sendo responsáveis por grande do processamento do carbono. O seu papel dentro da ciclagem do carbono irá variar de acordo com vários parâmetros, agindo como fatores regulatórios. O principal objetivo desse trabalho é de avaliar o metabolismo bacteriano em dois reservatórios do semiárido tropical. Foram coletadas trimestralmente amostras de água nos reservatórios Santa Cruz e Umari entre fevereiro de 2013 e e novembro de 2014. Foram analisados parâmetros físico-químicos e biológicos. O metabolismo bacteriano mostrou-se bastante variável e com pouca previsibilidade. Isso ocorre devido a grande diversidade de fatores regulatórios existentes que atuam em momentos e em locais diferentes, conjunta e separadamente. Frequentemente, se torna difícil prever os valores reais pois em diferentes momentos o metabolismo tanto pode ser influenciado pelas características físicas do sistema, bem como da concentração de nutrientes e suas implicações nas interações. Sendo assim, mostram-se indícios de que o metabolismo bacteriano sofre bastante influência tanto bottom-up como top-down, podendo sofrer a partir de mudanças, direcionadas ou aleatórias, na estrutura da comunidade.

Thesis
1
  • FABIANA OLIVEIRA DE ARAUJO SILVA
  • Adição de policloreto de alumínio e remoção de peixes bentívoros como técnica de restauração de lagos rasos do semiárido brasileiro

  • Advisor : JOSE LUIZ DE ATTAYDE
  • COMMITTEE MEMBERS :
  • ANDRE LUIS CALADO ARAUJO
  • ANDRE MEGALI AMADO
  • JOSE LUIZ DE ATTAYDE
  • JOSÉ ETHAM DE LUCENA BARBOSA
  • RENATA DE FÁTIMA PANOSSO
  • Data: Feb 3, 2015


  • Show Abstract
  • A eutrofização é a causa mais comum de deterioração da qualidade da água no mundo. Este processo se dá pela entrada excessiva de nutrientes, nitrogênio e fósforo, nos corpos aquáticos causando florações de algas e cianobactérias. Em lagos rasos esses efeitos são mais complicados devido a uma maior interação do corpo aquático com o entorno, com o ar e o sedimento. Existem várias técnicas de restauração de lagos eutrofizados, com uma vasta gama de resultados bem sucedidos, mas no Brasil há apenas um único caso de restauração bem sucedida: o lago Paranoá em Brasília. A região semiárida brasileira possui milhares de lagos artificiais, regionalmente chamados de açudes, em sua maioria rasos e eutróficos. A eutrofização desses corpos aquáticos é documentada e o fitoplâncton desses ambientes é frequentemente dominado por cianobactérias potencialmente tóxicas. O principal objetivo desta tese de doutorado é testar diferentes técnicas de restauração da qualidade da água que possam ser facilmente aplicadas em lagos rasos do semiárido brasileiro. Resultados de um experimento em laboratório sugerem que a aplicação de argila adsorvente de fósforo associada a um coagulante à base de alumínio é uma técnica efetiva na remoção do fósforo reativo solúvel e na diminuição da taxa de crescimento da Cylindrospermopsis raciborskii, cianobactéria potencialmente tóxica que domina nos reservatórios do semiárido brasileiro, mas que esse efeito é dependente da biomassa no momento da aplicação da técnica. Os resultados de um experimento de campo realizado em mesocosmos num lago raso eutrofizado demonstraram que a aplicação de coagulante à base de alumnínio em conjunto com a da remoção de peixes bentívoros é mais eficiente na remoção de fósforo total e clorofila-a da coluna de água do que a aplicação isolada de apenas uma dessas técnicas. Por fim, testes de laboratório demostraram que o coagulante à base de alumínio apresentou um bom desempenho em remover turbidez e fósforo total em testes de bancada com água de seis reservatórios do semiárido, sendo a eficiência reduzida com o aumento da biomassa de clorofila e pH. Os resultados deste estudo mostram que é possível melhorar a qualidade da água de reservatórios eutrofizados no semiárido brasileiro através do controle da carga interna de nutrientes seja pela precipitação e inativação do fósforo no sedimento, como também pela inibição da liberação do fósforo no sedimento por peixes bioturbadores, e que os resultados são aditivos quando as técnicas são aplicadas em conjunto.

2
  • DANYHELTON DOUGLAS FARIAS DANTAS
  • Causas e consequências da onivoria de peixes em ecossistemas aquáticos. 


  • Advisor : JOSE LUIZ DE ATTAYDE
  • COMMITTEE MEMBERS :
  • HUGO MIGUEL PRETO DE MORAIS SARMENTO
  • JOSE LUIZ DE ATTAYDE
  • KEMAL ALI GER
  • RAFAEL DETTOGNI GUARIENTO
  • ROSEMBERG FERNANDES DE MENEZES
  • Data: Feb 9, 2015


  • Show Abstract
  • A onívoria é uma estratégia alimentar comum entre os peixes tropicais, mas pouco se conhece sobre as possíveis causas e consequências deste padrão. Neste trabalho, levantamos a hipótese de que os peixes tropicais tendem a se alimentar mais baixo nas redes alimentares para compensar a maior demanda energética, a qual aumenta com a temperatura da água e o tamanho do corpo do animal. A análise dos dados de 8172 espécies de peixes marinhos e de água doce do mundo, de regiões tropicais e temperadas, demonstrou que a posição trófica dos peixes não carnívoros diminui com o aumento do tamanho do corpo em regiões tropicais, mas não em regiões temperadas. Este padrão sugere que a maior demanda energética dos peixes tropicais maiores deve ter exercido uma pressão seletiva para a evolução da onivoria. Como consequência, a dinâmica trófica dos ecossistemas aquáticos tropicais deve apresentar padrões distintos aos observados em ambientes temperados, com implicações importantes para o manejo da qualidade da água e a restauração de ecossistemas aquáticos eutrofizaos. Outra hipótese deste trabalho, é que os efeitos de peixes planctívoros onívoros sobre comunidades planctônicas tropicais dependem da composição estequiométrica dos produtores primários que por sua vez depende da disponibilidade relativa de luz e nutrientes. Um experimento de campo em mesocosmos manipulando a disponibilidade de luz e a presença de peixes planctívoros confirmou a hipótese de trabalho, sugerindo que a composição estequiometria e consequentemente a qualidade dos recursos alimentares determinam a estrutura trófica das redes alimentares pelágicas em lagos tropicais. Finalmente, outro experimento de campo em mesocosmos sugere que a remoção de peixes onívoros bentivoros deve ser mais eficaz do que a remoção de peixes onívoros planctívoros para a melhoria da qualidade da água de lagos e reservatórios tropicais. Este último experimento demonstrou que os peixes planctivoros onívoros aumentam a biomassa fitoplanctônica através do mecanismo de cascata trófica sem aumentar as concentrações de nutrientes na coluna d´água. Por outro lado, os peixes bentivoros onívoros, se alimentando de detritos e outros recursos bentônicos e excretando nutrientes na água, translocam nutrientes do sedimento para a coluna d´água, aumentando o aporte interno de fósforo e a biomassa fitoplanctônica através da sua interação com o sedimento. Portanto, o aporte interno de fósforo pode ser reduzido e a qualidade da água de lagos tropicais eutrofizados pode ser melhorada através da remoção de peixes bentívoros onívoros. 


3
  • CARLOS EDUARDO ROCHA DUARTE ALENCAR
  • Respostas ecológicas e morfológicas de três espécies de Portunoidea da Plataforma continental rasa Sudeste brasileira, Litoral norte de São Paulo.

  • Advisor : FULVIO AURELIO DE MORAIS FREIRE
  • COMMITTEE MEMBERS :
  • FULVIO AURELIO DE MORAIS FREIRE
  • ALLYSSON PONTES PINHEIRO
  • Adilson Fransozo
  • MARCELO ANTÔNIO AMARO PINHEIRO
  • Maria Lúcia Negreiros Fransozo
  • Data: Feb 20, 2015


  • Show Abstract
  • Respostas ecológicas e morfológicas de três espécies de Portunoidea da Plataforma continental rasa Sudeste brasileira, Litoral norte de São Paulo.

4
  • PAULO AUGUSTO DE LIMA FILHO
  • Diversidade cromossômica e padrões ecomorfológicos em Gobiidae (Perciformes) no litoral e ilhas oceânicas do Brasil

  • Advisor : WAGNER FRANCO MOLINA
  • COMMITTEE MEMBERS :
  • JOSE GARCIA JUNIOR
  • LUIZ ANTONIO CARLOS BERTOLLO
  • MARCELO DE BELLO CIOFFI
  • VITOR DE OLIVEIRA LUNARDI
  • WAGNER FRANCO MOLINA
  • Data: Mar 2, 2015


  • Show Abstract
  • A família Gobiidae é a mais diversificada no ambiente marinho, onde tamanha diversidade parece ter sido acompanhada por alterações cromossômicas significativas, a tornando um modelo biológico importante. Em geral apresentam ampla distribuição geográfica com características comportamentais e reprodutivas que as tornam propícias aos efeitos de barreiras biogeográficas. Comparados a outros representantes da ordem Perciformes apresenta características morfológicas reduzidas, com simplificações e perdas que dificultam estudos filogenéticos e tornam imprescindível a associação de novas metodologias para melhor entendimento dos processos ecológicos e evolutivos que garantiram tamanha diversificação. Dados citogenéticos para espécies presentes no litoral brasileiro são ínfimos. Os resultados aqui apresentados, abrangendo um maior espectro taxonômico e profundidade de análises, identificaram marcante diversidade cariotípica estrutural interespecífica para Coryphopterus glaucofraenum, Bathygobius mystacium, Bathygobius soporator, Bathygobius sp., Ctenogobius smaragdus, Ctenogobius boleosoma, Gobionellus oceanicus, Gobionellus stomatus, Microgobius meeki e Evorthodus lyricus. As espécies estudadas fazem parte de uma fauna críptica pouco percebida e estudada, frequentemente impactadas, mesmo por eventos locais estocásticos. Análises por morfometria geométrica indicaram variação significante na morfologia corporal de espécies do gênero Bathygobius e o reconhecimento de padrões de variação de forma corporal referentes ao sexo, com populações mais dimórficas em menores latitudes. Técnicas citogenéticas moleculares resolutivas aplicadas em estudos populacionais no litoral e em ilhas oceânicas identificaram diferenciações locais e reconheceram uma nova espécie para o gênero Bathygobius, residente no Atol das Rocas e Arquipélago de Fernando de Noronha. As análises ainda possibilitaram a descrição de cromossomos sexuais XY nas duas espécies do gênero Gobionellus e a participação de elementos repetitivos na diferenciação deste sistema. Os dados aqui apresentados dão suporte ao alto grau de diversificação evolutiva da família, ampliam o conhecimento citogenético para o grupo, permitem identificar estruturações populacionais e respostas evolutivas das espécies às variações geográficas. Como modelo biológico a família Gobiidae representa um útil contraponto evolutivo em relação aos padrões genéticos vigentes às espécies de grande vagilidade.

5
  • ADRIANA PELLEGRINI MANHÃES
  • On the relationship between plant biodiversity and ecosystem services in the Caatinga

  • Advisor : ADRIANA ROSA CARVALHO
  • COMMITTEE MEMBERS :
  • ADRIANA ROSA CARVALHO
  • ALEXANDRE FADIGAS DE SOUZA
  • CARLOS ROBERTO SORENSEN DUTRA DA FONSECA
  • INARA ROBERTA LEAL
  • MARCO ANTÔNIO PORTUGAL LUTTEMBARCK BATALHA
  • Data: Mar 13, 2015


  • Show Abstract
  • Muito tem se discutido na literatura sobre o papel da biodiversidade no funcionamento e serviços do ecossistema, que são benefícios essenciais para o bem-estar humano, derivados de processos ecológicos. Muitos experimentos em escala local já evidenciaram a importância da biodiversidade de plantas sobre o funcionamento do ecossistema, mas pouco se conhece ainda de como esta relação se desenvolve em sistemas naturais antropizados. Assim, o objetivo do primeiro capítulo desta tese foi avaliar como a biodiversidade de plantas e cobertura vegetal media os efeitos do uso da terra sobre as propriedades do ecossistema. Evidenciou-se a importância da diversidade (funcional e taxonômica) de plantas nas propriedades do ecossistema, como biomassa, fertilidade do solo e retenção de água no solo, além do efeito negativo do uso da terra. Já em uma escala maior, o entendimento da relação espacial dos serviços com a biodiversidade tem dado suporte às pesquisa na área de conservação da natureza. O segundo capítulo objetivou analisar a associação espacial entre biodiversidade de plantas e serviços e como estão distribuídos nas unidades de conservação do bioma Caatinga. Mostrou-se que as unidades de conservação não estão incluindo importantes áreas com alta biodiversidade de plantas e a maioria dos serviços do ecossistema (total de nove). Complementarmente, o capítulo 3 objetivou selecionar áreas prioritárias para conservação utilizando biodiversidade de plantas e serviços do ecossistema como alvos, assim como incluir custos socioeconômicos. Como resultado, a inclusão dos custos modificou a distribuição das áreas prioritárias, diminuindo a porcentagem protegida de principais serviços porém, com pouca influência na proteção da biodiversidade. Concluindo, esta tese contribui para o entendimento da relação entre biodiversidade de plantas e serviços do ecossistema no bioma Caatinga, e recomendações podem ser feitas para práticas de manejo em uma escala local, assim como, aplicações para conservação em uma escala importante para tomadores de decisões.

6
  • DAVID LUCAS ROHR
  • Variabilidade acústica e respostas evolutivas a diferentes pressões seletivas no canto de anúncio de anfíbios.

  • Advisor : ADRIAN ANTONIO GARDA
  • COMMITTEE MEMBERS :
  • ADRIAN ANTONIO GARDA
  • CARLOS BARROS DE ARAÚJO
  • CARLOS ROBERTO SORENSEN DUTRA DA FONSECA
  • MARCELO FELGUEIRAS NAPOLI
  • MARCIO ZIKAN CARDOSO
  • Data: May 19, 2015


  • Show Abstract
  • A comunicação acústica é fundamental para a reprodução da grande maioria dos anuros. O canto de anúncio tem como principal função atração de fêmeas para reprodução, atuando como barreira reprodutiva entre espécies. Desta forma, a compreensão dos processos evolutivos que levaram à diversidade acústica atual é fundamental para entendermos a evolução do clado como um todo. Esta tese tem como objetivo testar a importância de diferentes pressões seletivas na evolução do canto de anúncio dos anuros. O barulho ambiente é um dos principais obstáculos na comunicação acústica e espécies de anuros que reproduzem em riachos estão sobre constante pressão do barulho de água corrente. Utilizando método comparativo com um banco de dados de 509 espécies, mostramos que anuros que cantam em riachos apresentam cantos de anúncio com frequência dominante significativamente mais alta do que espécies de água parada, independente do tamanho corpóreo. Estes resultados indicam a importância dessa pressão seletiva para este clado, uma vez que frequências mais altas vão apresentar uma menor sobreposição espectral com o som grave da água corrente, diminuindo o mascaramento. Além do barulho ambiente, barreiras físicas que atrapalham a propagação do som podem atuar como pressão seletiva sobre sinais acústicos. Nesta tese, comparamos o canto de anúncio de Phyllomedusa nordestina na Mata Atlântica e na Caatinga, além de testar se os parâmetros acústicos estão relacionados à quantidade de vegetação em torno do sitio de vocalização. Resultados mostraram que dois parâmetros acústicos são significativamente afetados pelo tipo de bioma e dois pela quantidade de vegetação local, indicando que diferentes parâmetros acústicos de um mesmo canto podem apresentar caminhos evolutivos distintos: enquanto o intervalo entre pulsos e taxa de canto estão adaptados para o tipo de ambiente, os indivíduos também respondem de forma flexível à quantidade de vegetação, alterando a frequência dominante e o número de pulsos. 

7
  • LORENA CANDICE DE ARAÚJO ANDRADE
  • Estratégias de exploração e comércio da pesca artesanal de polvo

  • Advisor : TATIANA SILVA LEITE
  • COMMITTEE MEMBERS :
  • TATIANA SILVA LEITE
  • ADRIANA ROSA CARVALHO
  • FULVIO AURELIO DE MORAIS FREIRE
  • MANUEL HAIMOVICI
  • RODRIGO SILVA DA COSTA
  • Data: Nov 17, 2015


  • Show Abstract
  • Estratégias de exploração e comércio da pesca artesanal de polvo

8
  • CAMILA RODRIGUES CABRAL
  • Padrões de diversidade α e β zooplanctônica em lagos tropicais: a importância da estrutura do habitat e da identidade das espécies

  • Advisor : ADRIANO CALIMAN FERREIRA DA SILVA
  • COMMITTEE MEMBERS :
  • ADRIANO CALIMAN FERREIRA DA SILVA
  • ENEIDA MARIA ESKINAZI-SANT'ANNA
  • KEMAL ALI GER
  • LUCIANA SILVA CARNEIRO
  • RAFAEL DETTOGNI GUARIENTO
  • Data: Dec 11, 2015


  • Show Abstract
  • Esse estudo avalia os padrões de diversidade alfa, diversidade beta e similaridade das comunidades zooplanctônicas em 100 lagos rasos tropicais. No primeiro capítulo, nós verificamos a riqueza zooplanctônica entre os habitats limnético e litorâneo, se o resultado encontrado foi decorrente da presença de macrófitas no habitat litorâneo ou de condições do habitat per se, e quais foram as variáveis ambientais locais que mais influenciaram nos padrões de riqueza. Nossas hipóteses eram de que a riqueza seria maior no habitat litorâneo, principalmente para microcrustáceos, e que esses padrões seriam determinados pela presença de macrófitas. Nós vimos que o habitat litorâneo com macrófitas é detentor de maior riqueza zooplanctônica, especialmente de espécies de rotíferos beneficiadas pelo espectro de recursos providos pelas macrófitas. A riqueza de microcrustáceos não foi afetada pelas macrófitas, possivelmente devido ao tamanho reduzido desses organismos e à baixa predação visual e hábito omnívoro de peixes tropicais. Encontramos relação positiva entre a riqueza com a presença de macrófitas e a baixa concentração de nitrogênio. É possível que, devido às consequências da eutrofização, o aumento dos nutrientes na água determina: o aumento da biomassa algas e a redução de macrófitas, e consequentemente, a redução da riqueza zooplanctônica. Já no segundo capítulo,nós observamos que o efeito combinado da heterogeneidade de habitats (habitat limnético ou litorâneo) e a ausência direta de conectividade entre os lagos foram fundamentais no aumento da diversidade beta zooplanctônica, e que, a complexidade estrutural (presença de macrófitas) exerceu importante papel sobre a diversidade beta em escalas local e regional. A variação espacial, como a promovida pela compartimentalização horizontal em lagos e pela presença de macrófitas no habitat litorâneo, foi capaz de produzir mosaicos e gradientes capazes de permitir a coexistência de diferentes espécies adaptadas às condições específicas criadas pela variabilidade dos habitats limnético e litorâneo. Dentre esses habitats, o litorâneo constituiu a região mais sujeita a efeitos do filtro ambiental em escala regional, apresentando maior diversidade beta e heterogeneidade ambiental, possivelmente devido à maior complexidade espacial e temporal de fatores físico-químico e biológicos. Enquanto que, no terceiro capítulo, nós vimos os padrões do zooplâncton de decaimento da similaridade com a distância (DDS), considerando o potencial de dispersão dos organismos e a idade do lagos. Devido ao potencial de dispersão, nós esperávamos que as taxas de DDS fossem maiores para copépodes, cladóceros e rotíferos, respectivamente, e que, devido ao maior tempo de existência dos lagos antigos e ao potencial de dispersão do zooplâncton, as medidas de similaridade inicial fossem maiores e as taxas de DDS menores nos lagos antigos. Nós vimos que dentro de cada conjunto de lagos as taxas de DDS não variaram entre os organismos, evidenciando que além da habilidade de dispersão per se, existem outros fatores que contribuíram para inexistência de decaimento mais rápidos entre os grupos. As taxas de DDS foram mais evidentes nos lagos mais novos, possivelmente, o tempo tornou os lagos antigos mais complexos e heterogêneos, capazes de agir como filtro ambiental na seleção de diferentes espécies. A DDS significativa do zooplâncton em escalas espaciais relativamente pequenas comprova que organismos pequenos podem apresentar padrões biogeográficos semelhante ao esperado para os macrorganismos. Por fim, os três capítulos em conjunto forneceram informações importantes sobre os fatores que controlam a riqueza e distribuição zooplanctônica no espaço e no tempo e pode auxiliar-nos na previsão de respostas ecossistêmicas, diante da eutrofização cultural ou das mudanças climáticas globais, e nas ações de conservação e estratégias de conservação de ecossistemas lacustres.

9
  • CAROLINE GABRIELA BEZERRA DE MOURA
  • Mecanismos de emissão de CO2 em reservatórios do semiárido brasileiro

  • Advisor : ANDRE MEGALI AMADO
  • COMMITTEE MEMBERS :
  • ANDRE MEGALI AMADO
  • JOSE LUIZ DE ATTAYDE
  • VANESSA BECKER
  • HUGO MIGUEL PRETO DE MORAIS SARMENTO
  • VINICIUS FARJALLA
  • Data: Dec 14, 2015


  • Show Abstract
  • Mecanismos de emissão de CO2 em reservatórios do semiárido brasileiro

2014
Dissertations
1
  • MARCIO LUIZ FARIAS RATO
  • O Histórico de uma Pesca Tropical Utilizando Indicadores Ecossistêmicos.

  • Advisor : PRISCILA FABIANA MACEDO LOPES
  • COMMITTEE MEMBERS :
  • PRISCILA FABIANA MACEDO LOPES
  • RONALDO ANGELINI
  • RODRIGO SILVA DA COSTA
  • Data: Feb 11, 2014


  • Show Abstract
  • Estudos que abordem o Nível Trófico Médio de Captura (MTL) com a intenção de propor medidas de manejo pesqueiro não podem se restringir apenas à hipótese do “Fishing Down Food Webs”, ignorando, por exemplo, outros dois cenários possíveis, “Fishing Through Food Webs” e “Increase to Overfishing”. No entanto, o teste conjunto destas hipóteses ainda é raro em geral para pescarias tropicais. Assim, o objetivo desse trabalho foi investigar se um destes cenários aplica-se ao entendimento de uma pescaria no nordeste do Brasil, para a qual há dados temporais ao longo de 30 anos. Simultaneamente foram consideradas informações econômicas, como os subsídios disponíveis para a pesca industrial para a compra de óleo diesel. O cenário encontrado foi “Increase to overfishing”, provavelmente em função dos mecanismos políticos que facilitam o aumento do esforço da pesca. A lei nacional da subvenção de óleo diesel e os acordos de pescas entre empresas nacionais e países estrangeiros promovem o aumento da captura em diferentes níveis da cadeia trófica, principalmente dos predadores de topo.

2
  • ANNA CLAUDIA DOS SANTOS
  • xxx

  • Advisor : ADRIANA MONTEIRO DE ALMEIDA
  • COMMITTEE MEMBERS :
  • ADRIANA MONTEIRO DE ALMEIDA
  • ADRIANO CALIMAN FERREIRA DA SILVA
  • THIAGO SANNA FREIRE SILVA
  • Data: Feb 24, 2014


  • Show Abstract
  • xxx

3
  • JOSÉ LUIZ ALVES SILVA
  • MECANISMOS DE VARIAÇÃO FLORÍSTICA EM UMA METACOMUNIDADE SOBRE DUNAS COSTEIRAS NO NORDESTE DO BRASIL

  • Advisor : ALEXANDRE FADIGAS DE SOUZA
  • COMMITTEE MEMBERS :
  • ALEXANDRE FADIGAS DE SOUZA
  • GABRIEL CORREA COSTA
  • GISLENE MARIA DA SILVA GANADE
  • LUIZ ANTONIO CESTARO
  • Data: Feb 28, 2014


  • Show Abstract
  • Para entender a estrutura de metacomunidades deve se considerar tanto explicações ligadas ao nicho das espécies como mecanismos neutros. Em ambientes estressantes da floresta Atlântica a diversidade de plantas é geralmente baixa e constituída de muitas espécies raras. Várias explicações baseadas no nicho têm sido propostas para aceitar este padrão estrutural. Investigamos se um padrão similar em uma metacomunidade de Restinga no NE do Brasil sugere a predominância de um dos mecanismos na montagem composicional. Para isto foi feito um levantamento da abundância das espécies e de características ambientais abióticas de 85 parcelas (25 m²) em uma Restinga no município do Natal-RN. Também levantamos suas posições espaciais como indicadores da contribuição neutra. Análises de partição da variância baseadas em RDA e modelos de efeito misto foram usadas para decompor a explicação da variação composicional. Nossos resultados revelaram a necessidade de considerar tanto explicações ligadas aos gradientes de estresse do sistema costeiro como da neutralidade. A variação da abertura do dossel e de certas propriedades físico-químicas do solo (ex. ácido potencial, pH e Na) e da topografia (ex. declividade e altitude) foram os principais promotores abióticos de variação florística pela partição da variância. Esta análise também selecionou processos espaciais significativos de escala ampla e intermediária. Já os modelos mistos sugeriram a abertura do dossel como a única variável abiótica e escalas espaciais amplas e finas como indicadoras de processos neutros. Uma interpretação que aponte o mecanismo dominante depende desta forma da abordagem analítica usada, que pode favorecer a necessidade de requerimentos de nicho específicos ou ocorrências oportunistas sem adaptações necessárias ao ambiente costeiro.
4
  • MARIA DA CONCEIÇÃO DE SOUZA
  • Influência das Mudanças Climáticas na Estrutura Funcional da Comunidade Fitoplanctônica em um Reservatório da Região do Semiárido

  • Advisor : VANESSA BECKER
  • COMMITTEE MEMBERS :
  • VANESSA BECKER
  • RENATA DE FÁTIMA PANOSSO
  • LUCIA HELENA SAMPAIO DA SILVA
  • Data: Mar 7, 2014


  • Show Abstract
  • O Nordeste é a região do Brasil mais exposta aos riscos da variabilidade climática. Para o semiárido brasileiro é esperada uma redução nos índices totais de precipitação e aumento da variabilidade nos padrões de incidênica de precipitação, além de um aumento no número de dias secos. Tais mudanças afetarão a intensidade e duração de chuvas e secas que poderão promover a dominação de cianobactérias, afetando assim, a qualidade da água dos reservatórios no semiárido. O objetivo deste trabalho foi avaliar os efeitos do aumento de temperatura combinado com enriquecimento de nutrientes sobre a estrutura funcional da comunidade fitoplanctônica de um reservatório mesotrófico no semiárido, no cenário mais pessimista de mudanças climáticas previstas pelo IPCC -Intergovernmental Panel on Climate Change (2007). Foram realizadas duas coletas de água, uma no período chuvoso e outra no seco. A água coleta foi armazenada em béqueres de vidro e submetida à adição de nutrientes (nitrato e fósforo solúvel) em diferentes concentrações. Os microcosmos foram submetidos a duas temperaturas diferentes, controle (média de cinco anos da temperatura do ar no reservatório) e aquecimento (4°C acima da temperatura controle). Durante o experimento foram coletadas amostras para as análises químicas e fitoplanctônicas. Os resultados mostram que a comunidade fitoplanctônica dos experimentos do período chuvoso e seco respondeu de forma distinta aos efeitos do aquecimento e que o enriquecimento teve pouco efeito sobre a sua estrutura. No período chuvoso foi verificado o aumento da biomassa de grupos funcionais de algas unicelulares pequenas e oportunistas, como o F e X1. O aumento da biomassa de grupos funcionais constituídos de clorofíceas mostra que as cianobactérias se beneficiam do aumento da estabilidade d’água causada pelo aquecimento e não de seu efeito direto. No período seco houve uma maior contribuição na biomassa relativa de algas filamentosas, com uma substituição do grupo S1 pelo H1, nos tratamentos enriquecidos.

5
  • MARIANA RODRIGUES AMARAL DA COSTA
  • O IMPACTO DA REMOÇÃO DE PEIXES SOBRE A DINÂMICA E ESTRUTURA FUNCIONAL DA COMUNIDADE FITOPLANCTÔNICA EM UM LAGO RASO TROPICAL DURANTE UMA SECA SEVERA

  • Advisor : VANESSA BECKER
  • COMMITTEE MEMBERS :
  • VANESSA BECKER
  • JOSE LUIZ DE ATTAYDE
  • VERA LUCIA DE MORAES HUSZAR
  • Data: Mar 20, 2014


  • Show Abstract
  • A eutrofização artificial é uma das grandes ameaças à qualidade ambiental de ecossistemas aquáticos em todo o mundo. As expectativas dos cenários climáticos futuros são períodos de secas mais intensas e frequentes, aumentando ainda mais o risco de eutrofização e de florações de cianobactérias. Muitas técnicas de restauração de lagos vêm sendo realizadas para reduzir as cargas de nutrientes e melhorar a qualidade da água. Uma técnica bastante utilizada nesse sentido é a biomanipulação por remoção de peixes que vêm se mostrando eficiente em lagos eutróficos de regiões temperadas. Aplicamos esta técnica em um lago raso artificial eutrofizado localizado na região semiárida tropical, com o objetivo de restaurar o sistema. Trabalhando com a hipótese de que a remoção de peixes bentívoros bioturbadores reduz a biomassa total do fitoplâncton e altera a composição dos grupos funcionais, melhorando a qualidade da água, nosso estudo teve como objetivo avaliar o impacto da biomanipulação na estrutura funcional do fitoplâncton e na qualidade da água. Para compararmos os resultados do lago biomanipulado monitoramos um lago vizinho como controle (sem biomanipulação). Nosso período de estudo contemplou os meses de Maio de 2012 a Setembro de 2013 coincidindo com um período de seca severa, com chuvas abaixo da média, na região. Antes da biomanipulação a comunidade fitoplanctônica foi dominada pelo grupo funcional SN, representado por cianobactérias heterocitadas formadoras de florações, no lago experimental. Como resultado da biomanipulação observamos a redução da concentração de nutrientes, aumento da luminosidade, redução da biomassa algal, o aumento da riqueza de grupos funcionais e o recrutamento de algas verdes (F e J). No lago controle, observamos um comportamento oposto, com o incremento da biomassa algal ao longo do período de estudo, principalmente do grupo SN. Associamos esse fato com o período de seca severa, que proporcionou um alto tempo de residência e concentração de nutrientes. Este período de seca proporcionou uma redução no nível de água que influenciou na disponibilidade de recursos, sendo um importante fator direcionador para a dinâmica de grupos funcionais fitoplanctônicos. O efeito da seca foi também verificado no lago experimental antes da aplicação da técnica de biomanipulação, com o colapso da biomassa algal  e recrutamento de grupos funcionais de espécies flageladas (W1, W2, Y). Sumarizando, a remoção dos peixes bentívoros bioturbadores promoveu mudanças significativas na melhora da qualidade da água do lago artificial do semiárido, refletindo em uma mudança na composição funcional e na biomassa fitoplanctônica. Entretanto, o período de seca severa, anterior à aplicação da biomanipulação, proporcionou uma degradação da qualidade dos lagos, devido ao baixo nível d’água e concentração de nutrientes. Este evento refletiu em comportamentos distintos dos sistemas estudados como, o colapso da biomassa algal, devido a alta turbidez inorgânica no lago experimental e o incremento da biomassa no lago controle. Concluímos que a técnica de biomanipulação no semiárido tropical é promissora e eficaz, mesmo sob condições de seca extrema.

6
  • FABIOLA DA COSTA CATOMBE DANTAS
  • SATURAÇÃO EM CO2 E REGULAÇÃO METABÓLICA DO BACTERIOPLÂNCTON EM ECOSSISTEMAS AQUÁTICOS DE BAIXA LATITUDE.

  • Advisor : ANDRE MEGALI AMADO
  • COMMITTEE MEMBERS :
  • ANDRE MEGALI AMADO
  • ADRIANO CALIMAN FERREIRA DA SILVA
  • HUGO MIGUEL PRETO DE MORAIS SARMENTO
  • Data: Mar 28, 2014


  • Show Abstract
  • Ecossistemas aquáticos continentais são frequentemente emissores de CO2 para atmosfera, e as bactérias planctônicas são atuantes nesse cenário pela respiração da matéria orgânica dissolvida, sobretudo em baixas latitudes. Neste estudo, foi avaliado o grau de saturação de CO2 (pCO2) e o metabolismo bacteriano em 100 ecossistemas aquáticos continentais de clima úmido e semiárido do Nordeste Brasileiro (Rio Grande do Norte) em setembro de 2012. Dos 100 sistemas avaliados, 71% foram eutróficos e hipereutróficos e 90% foram supersaturados em CO2. Apesar da escala de variação latitudinal ter sido de apenas dois graus, observamos uma variação ampla nos níveis de pCO2. Quanto ao metabolismo bacteriano, as taxas de Respiração Bacteriana (RB) foram elevadas, e a Produção Bacteriana (PB) foi relativamente baixa, resultando nas mais baixas eficiências de crescimento bacteriano (mediana <1%) registradas na literatura para dados limnológicos. Não registramos relações diretas entre a RB e a pCO2, o que pode estar relacionado a ausência de precipitação e baixa entrada de carbono alóctone para subsidiar a RB e heterotrofia no período estudado. A heterogeneidade das características intrínsecas de cada ecossistema leva a fatores explanatórios divergentes entre PB e RB. Nossos resultados parecem sustentar o novo paradigma tropical a respeito da pouca importância da incorporação de carbono microbiano para sustentação da produção secundária aquática em detrimento na evasão de CO2 liberado pela respiração.

7
  • TALITA FERREIRA AMADO
  • Ecologia Trófica de Anfíbios Anuros: Relações Filogenéticas em Diferentes Escalas

  • Advisor : ADRIAN ANTONIO GARDA
  • COMMITTEE MEMBERS :
  • ADRIAN ANTONIO GARDA
  • CARLOS ROBERTO SORENSEN DUTRA DA FONSECA
  • PRISCILA LEMES DE AZEVEDO SILVA
  • Data: Apr 16, 2014


  • Show Abstract
  • Entender a origem, manutenção e os mecanismos que operam na biodiversidade atual são um dos principais objetivos da Ecologia. A ecologia das espécies pode ser influenciada por diferentes fatores em diferentes escalas. Existem três abordagens a cerca das diferenças ecológicas entre as espécies: a primeira traz essas diferenças resultam de processos atuais atuando sobre as características do nicho (dieta, tempo, espaço, etc); a segunda que divergências no nicho das espécies são explicadas por padrões randômicos de especiação, dispersão e extinção; a terceira que eventos históricos explicam a formação e a composição das espécies nas comunidades. Este estudo tem como objetivo avaliar a influência das relações filogenéticas na determinação de características ecológicas em anfíbios (globalmente) e testar, com isso, se as diferenças ecológicas entre as espécies de anuros são resultado de diferenças antigas pré-existentes ou como o resultado de interações ecológicas mais recentes. Outro objetivo deste estudo é verificar que características ecológicas, históricas ou atuais, determinam e influenciam o tamanho da distribuição geográfica das espécies. Os dados de dieta para a análise da ecologia trófica dos anfíbios serão coletados a partir da literatura já publicada. Realizamos Análise de Correspondência Filogenética para testar a existência de efeitos filogenéticos na estrutura das comunidades de e anfíbios. Com isso, espera-se conhecer os principais fatores que permitem a coexistência das espécies de anfíbios anuros e quais os principais nós da filogenia de anfíbios responsáveis pelas diferenças observadas atualmente no nicho trófico das espécies. Realizamos uma regressão filogenética para analisar se as variáveis de largura de nicho, tamanho corporal e tempo de divergência determinam o tamanho da distribuição geográfica dos anfíbios anuros da Amazônia.

8
  • GUIDO DE GREGORIO GRIMALDI
  • BASE DE DADOS ECOLÓGICOS DAS COMUNIDADES RECIFAIS SUBTIDAIS DE PIRANGI, RN, BRASIL, ENFOCANDO SEU ESTADO DE CONSERVAÇÃO

  • Advisor : TATIANA SILVA LEITE
  • COMMITTEE MEMBERS :
  • CRISTIANO QUEIROZ DE ALBUQUERQUE
  • EDUARDO MARTINS VENTICINQUE
  • LIANA DE FIGUEIREDO MENDES
  • TATIANA SILVA LEITE
  • Data: Apr 28, 2014


  • Show Abstract
  • Em diversos recifes coralíneos do Caribe e de regiões do Indo-Pacífico, estudos têm relatado críticas mudanças na estrutura das comunidades bentônicas decorrente de distúrbios, em sua maioria, de origem humana. Por essa razão, têm se buscado fazer descrições apuradas de como as diferentes comunidades recifais encontram-se estruturadas e em determinar o estado ecológico dos recifes antes que mais mudanças ocorram, de modo que se estabeleça uma referência base que sirvam de comparativo para os programas de monitoramento. Dessa forma, o presente trabalho tem como objetivo geral contribuir diretamente para a ampliação e geração de conhecimento científico na região, sobretudo no que diz respeito aos recifes submersos de Pirangi, de modo a estabelecer uma base de dados (baseline) do atual estado ecológico em que se encontram, servindo como de referência para futuros estudos ecológicos e buscando auxiliar na definição de locais que necessitem de manejo e conservação, ao fornecer as informações científicas necessárias para amparar as tomadas de decisões na área ambiental. Foram estudadas sete formações recifais de 15 à 28m de profundidade, em Pirangi e proximidades, Rio Grande do Norte/Brasil. O artigo 1 caracterizou ecologicamente a região de estudo quanto aos principais descritores da comunidade, sua diversidade e os principais grupos funcionais encontrados. O artigo 2 assinalou as particularidades (estruturais, biológicos e uso antrópico) de cada recife, comparando quanto ao uso e estado ecológico atual, visando assim subsidiar propostas futuras de manejo e então, conservação das áreas recifais na região.

9
  • ALINA ROCHA PIRES BARBOZA
  • Caracterização da comunidade bentônica do recife raso de Pirangi/RN, Brasil, e avaliação do seu processo de estruturação sob impacto de pisoteio

  • Advisor : TATIANA SILVA LEITE
  • COMMITTEE MEMBERS :
  • TATIANA SILVA LEITE
  • GISLENE MARIA DA SILVA GANADE
  • SÉRGIO ROSSO
  • Data: Apr 30, 2014


  • Show Abstract
  • Ambientes recifais sofrem com os impactos do pisoteio humano, prejudicial à estrutura da comunidade bentônica. Esse trabalho objetivou 1) caracterizar a comunidade bentônica no recife de Pirangi/RN, identificando padrões de zonação, e 2) avaliar o seu processo de estruturação sob diferentes graus de pisoteio. Foram coletados dados de abundância dos organismos, porcentagem de cobertura do substrato e parâmetros físico-químicos. Para responder ao primeiro objetivo, foram amostradas estações com diferentes tempos de exposição. Verificou-se a formação de duas zonas: uma abrangendo áreas submersas e de menor tempo de exposição, de menor rugosidade e maior heterogeneidade na cobertura de substrato, relacionada a organismos como gastrópodes, caranguejos e ouriço-do-mar; a segunda zona compreende áreas de maior tempo de exposição, maior rugosidade e predomínio de substrato rochoso, associada à organismos como cracas, gastrópodes, bivalves e caranguejos. Conclui-se que o recife apresenta padrão próprio de zonação, influenciado tanto pelo tempo de emersão quanto por características do substrato. Para o segundo objetivo deste trabalho, foram montados experimentos nas áreas com diferentes intensidades de pisoteio, contendo os tratamentos: controle (isolado de pisoteio), isolado raspado, pisoteio e pisoteio raspado. Dados de abundância, índices de diversidade e cobertura viva foram comparados e os resultados mostraram que não houve diferença na estrutura da comunidade dos tratamentos raspados, porém, a fauna raspada desses tratamentos apresentou uma abundância de organismos menor na área de pisoteio intermediário. Entre os tratamentos não raspados, observou-se uma maior abundância da fauna móvel e riqueza da cobertura viva na área de impacto elevado, enquanto a área de pisoteio intermediário apresentou uma maior porcentagem de cobertura viva. As áreas controle iniciais e finais diferiram apenas quanto à porcentagem de cobertura viva. As áreas que foram raspadas e isoladas não diferiram do tratamento pisoteio ao término do experimento. Sugere-se que a atividade de pisoteio em Pirangi seja descentralizada. 

10
  • LAISSA MACEDO TORRES
  • EFEITO DA SECA NA DINÂMICA DOS GRUPOS FUNCIONAIS FITOPLANCTÔNICOS EM RESERVATÓRIOS EUTRÓFICOS DO SEMIÁRIDO

  • Advisor : VANESSA BECKER
  • COMMITTEE MEMBERS :
  • JOSÉ ETHAM DE LUCENA BARBOSA
  • LUCIANA GOMES BARBOSA
  • VANESSA BECKER
  • Data: Jul 30, 2014


  • Show Abstract
  • Reservatórios são os principais recursos de água superficial no semiárido do Brasil. A grande maioria destas reservas de água está comprometida pela eutrofização. A seca severa ocorrida em 2012 contribuiu para perdas consideráveis no volume de água, influênciando a disponiblidade de recursos (nutriente e luz) para o fitoplâncton. O objetivo do trabalho foi verificar o efeito da seca na dinâmica de grupos funcionais fitoplanctônicos e verificar os fatores direcionadores de cada grupo. O efeito da seca favoreceu a homogeneidade de variávies bióticas e abióticas nos reservatórios, principalmente pela falta de fluxo dos rios intermitentes. Os grupos funcionais de cianobactérias formadoras de florações (S1, M e SN) dominaram ao longo do ano de 2012, nos três reservatórios estudados (Dourado, Gargalheiras e Passagem das Traíras). Os grupos estiveram relacionados à altas concentrações de sólidos voláteis, fósforo total (PT) e amônia (NH3), além de dominar tanto em ambientes rasos como em ambientes mais profundos. Cylindrospermopsis raciborskii (grupo SN) foi a espécie mais representativa nos três reservatórios, apresentando as maiores biomassas. O grupo M (Sphaerocavum brasiliense), ao contrário do descrito na literatura, registrou seu melhor desempenho em ambientes rasos, com mistura da coluna d’água. A abordagem dos grupos funcionais de Reynolds et al. (2002) representou uma ferramenta importante na descrição dos sistemas eutróficos do semiárido, mas não refletiu  uma resposta clara dos fatores direcionadores de cada grupo. Devido à longa dominância de cianobactérias nos reservatórios do semiárido, sugerimos que a abordagem de grupos taxonômicos indica mais claramente quais características ambientais contribuem para o melhor desemprenho desse grupo. Ambientes ricos em nutrientes, alto tempo de retenção da água, alta disponibilidade de luz durante quase todo o ano e estabilidade na coluna d’água por falta de fluxo são características dos reservatórios do semiárido que favorecem a dominância dos grupos de cianobactérias formadoras de florações. Sendo assim, nossos resultados mostram que os reservatórios do semiárido são vulneráveis à dominância de cianobactérias formadoras de florações, especialmente em períodos de eventos extremos, como seca severa, refletindo na perda da qualidade de água nos mananciais da região.

     
11
  • AMARILYS DANTAS BEZERRA
  • Influências da estrutura espacial, do ambiente e do histórico de extração de madeira na estrutura de uma floresta mista subtropical

  • Advisor : ALEXANDRE FADIGAS DE SOUZA
  • COMMITTEE MEMBERS :
  • ALEXANDRE FADIGAS DE SOUZA
  • GISLENE MARIA DA SILVA GANADE
  • LEONALDO ALVES DE ANDRADE
  • Data: Dec 18, 2014


  • Show Abstract
  • Um dos principais objetivos da ecologia é entender os fatores que influenciam a formação e a estrutura das comunidades. Vários trabalhos têm apontado que os fatores ambientais e estocásticos são igualmente relevantes, embora suas importâncias variem entre comunidades. Diferentes mecanismos parecem atuar em grupos de espécies distintos e em escalas distintas: a importância do determinismo ecológico parece aumentar com o tamanho do organismo, com a progressão da sucessão ecológica e com o aumento da escala espacial e decrescer com o tamanho do propágulo e o tamanho do conjunto regional de espécies. Haveria também dinâmicas diferentes entre espécies raras e abundantes, sendo as espécies raras mais influenciadas pela estocasticidade que as abundantes. Neste trabalho investigamos a contribuição dos efeitos ambientais, espaciais e relacionados aos eventos históricos na estrutura de uma floresta mista subtropical e testamos as seguintes hipóteses: (1) Os fatores estocásticos, representados pela fração puramente espaciais, têm maior influência nas comunidades recém impactadas (início da sucessão), enquanto que os fatores ambientais têm maior influência nas não impactadas ou há mais tempo em regeneração; (2) A importância relativa dos fatores espaciais é maior na estrutura das espécies de grupos ecológicos com melhor capacidade dispersiva; (3) Os fatores históricos e espaciais são mais impactantes para as espécies raras que para as espécies abundantes. Chegamos à conclusão que os fatores ambientais foram tão importantes quanto os demais processos analisados para a definição da estrutura da comunidade. Também que os fatores ambientais, espacias e históricos tiveram influências diferentes em grupos de espécies com estratégias ecológicas distintas e em áreas com históricos de pertubação diferentes. A inclusão dos fatores históricos demonstrou ser bastante relevante para o entendimento da estrutura da comunidade. Consideramos que a inclusão dos principais fatores de pertubação nas análises pode aprofundar nosso entendimento dos processos ligados à formação das comunidades ecológicas.

Thesis
1
  • SERGIO RICARDO DE OLIVEIRA
  • Fluxo de nutrientes em um sistema de aquicultura orgânica

  • Advisor : ELIANE MARINHO SORIANO
  • COMMITTEE MEMBERS :
  • ELIANE MARINHO SORIANO
  • MARCELLA ARAÚJO DO AMARAL CARNEIRO
  • MARCOS ROGERIO CAMARA
  • PIO COLEPICOLO NETO
  • SATHYABAMA CHELLAPPA
  • Data: Feb 26, 2014


  • Show Abstract
  • O cultivo de camarão marinho em sistema orgânico tornou-se uma alternativa menos danosa ao meio ambiente. A junção deste sistema com o cultivo integrado (alga/camarão) é uma forma econômica e socialmente benéfica de reduzir os impactos ambientais provenientes desta atividade. Este estudo focaliza sobre o fluxo de nutrientes em um sistema de cultivo de camarão orgânico (Litopenaeus vannamei) e sobre a capacidade de absorção de nitrogênio e fósforo das macroalgas Gracilariopsis tenuifrons, Gracilaria caudata, Gracilaria domingensis e Ulva lactuca quando cultivada nesses sistemas. Esta tese está constituída em quatro capítulos. O capítulo 1 está na forma de uma introdução a qual destaca o estado atual da aquicultura, os sistemas de cultivos, o conhecimento atual dos cultivos integrados e as espécies algais mais utilizadas como biofiltros. Este capítulo também justifica e sublinha a necessidade de empreender a pesquisa atual. O capítulo 2 analisa o fluxo de nutrientes (NH4+, NO2-, NO3-e PO4-) e avalia os parâmetros ambientais em viveiros de camarão orgânico (Litopenaeus vannamei). Nesse estudo a qualidade da água e do sedimento dos viveiros foi determinada durante um período correspondendo a um ciclo do camarão. Estes dados foram combinados com informações sobre os parâmetros físicos e químicos de maneira a investigar quais variáveis influenciam o crescimento e sobrevivência dos camarões. O capitulo 3, avalia a relação entre carga de nutrientes, taxa de remoção e assimilação de nutrientes pela macroalga Gp.tenuifrons quando cultivada em água residual do cultivo orgânico. Aspectos relacionados a fisiologia da alga tais como composição pigmentar, taxa fotossintética e crescimento foi avaliado em laboratório. Finalmente, no capítulo 4, o potencial de biorremediação e assimilação do nitrogênio e fósforo em G. Caudata, G. domingensis e U. lactuca foi estimado em outdoor. A avaliação do papel do cultivo orgânico integrado é também discutida. Todos estes capítulos dão forma a esta pesquisa e podem ser vistos como informações importantes para a aquicultura orgânica. 

2
  • CRISTIANE GOUVEA FAJARDO
  • Conservação genética da orquídea Cattleya granulosa

  • Advisor : WAGNER FRANCO MOLINA
  • COMMITTEE MEMBERS :
  • WAGNER FRANCO MOLINA
  • FABIO DE ALMEIDA VIEIRA
  • JOMAR GOMES JARDIM
  • LILIAN GIOTTO ZAROS DE MEDEIROS
  • LEONARDO PESSOA FÉLIX
  • MURILO MALVEIRA BRANDÃO
  • Data: Feb 28, 2014


  • Show Abstract
  • Cattleya granulosa Lindley é uma orquídea endêmica de da Floresta Atlântica do litoral do Nordeste brasileiro. A facilidade de coleta, e distribuição em áreas costeiras de interesse econômico tornam suas populações um alvo constante da coleta predatória, que também sofrem degradação ambiental. Devido ao impacto gerado em suas populações, a espécie está ameaçada. Este estudo teve como objetivos avaliar os níveis de agregação espacial em uma população preservada, analisar as relações filogenéticas de C. granulosa com outras quatro espécies de Laeliinae (Brassavola tuberculata, C. bicolor, C. labiata e C. schofieldiana) e ainda avaliar a diversidade genética remanescente de 12 populações de C. granulosa, por meio de marcadores ISSR. Verificou-se especificidade da epífita C. granulosa com um único forófito, indivíduos arbóreos de Eugenia spp. C. granulosa possui padrão espacial agregado, com maior densidade de vizinhos no raio de até 5 m. Nas relações filogenéticas, C. bicolor exibiu o maior índice de diversidade genética (HE = 0,219), enquanto C. labiata exibiu o nível mais baixo (HE = 0,132). A porcentagem de variação genética entre as espécies (AMOVA) foi de 23,26%. A análise de componentes principais (PCA) mostrou divergência genética entre as espécies unifoliadas e bifolioladas. A PCA também indicou uma relação estreita entre C. granulosa e C. schofieldiana, que é considerada por muitos pesquisadores uma variedade de C. granulosa. No estudo de genética de populações, todos os locos foram polimórficos. A alta diferenciação genética das populações (ФST = 0,391; P < 0,0001) determinou a estruturação em nove grupos, conforme modelo Log-likelihood da análise Bayesiana, com padrão similar no dendrograma (UPGMA) e PCA. Houve correlação positiva e significativa entre as distâncias geográficas e genéticas entre as populações (r = 0,794; P = 0,017), indicando o isolamento pela distância. Padrões de diversidade alélica sugerem a ocorrência de gargalos populacionais na maioria das populações de C. granulosa (n = 8). Assim, a manutenção da diversidade genética da espécie está diretamente relacionada com a conservação das unidades ou grupos que estão espacialmente distantes.

3
  • VINÍCIUS DE AVELAR SÃO PEDRO
  • FILOGEOGRAFIA DE ANFÍBIOS DA DIAGONAL DE ÁREAS ABERTAS DA AMÉRICA DO SUL

  • Advisor : ADRIAN ANTONIO GARDA
  • COMMITTEE MEMBERS :
  • ADRIAN ANTONIO GARDA
  • FERNANDA DE PINHO WERNECK
  • GABRIEL CORREA COSTA
  • NELSON JURANDI ROSA FAGUNDES
  • SERGIO MAIA QUEIROZ LIMA
  • Data: May 29, 2014


  • Show Abstract
  • A diagonal de áreas abertas, ou “diagonal seca”, é uma região de grande riqueza de espécies e reconhecida importância biogeográfica na América do Sul. Formada por Caatinga, Cerrado e Chaco, sua diversidade ainda está subestimada e pouco se conhece acerca dos processos que deram origem à sua biota. Para investigar a importância de eventos geológicos e climáticos nos processos de diversificação, foi realizada uma abordagem genética multilocus de ampla abrangência geográfica em dois grupos de anfíbios (Dermatonotus muelleri e Phyllomedusa grupo hypochondrialis). Os dados moleculares foram interpretados à luz da teoria da coalescência e inferência bayesiana. Técnicas como rede de haplótipos, reconstrução filogeográfica, modelagem de nicho, testes de migração e ABC foram utilizadas como análises complementares. Foram reconhecidas duas linhagens distintas em Dermatonotus, que se diferenciaram durante eventos orogênicos do Mioceno/Plioceno. A influência das variações climáticas do Pleistoceno se limitaram a mudanças no tamanho populacional de uma das linhagens. Em Phyllomedusa, foram identificadas ao menos quatro linhagens geograficamente estruturadas. Uma complexa história de diversificação explica o surgimento dessas linhagens, começando por especiação alopátrica durante o Neógeno, envolvendo o soerguimento do Planalto Central e oscilações na vazão do Rio São Francisco, até os eventos de expansão e retração dos biomas durante o Pleistoceno. Os resultados do presente estudo colaboram com a taxonomia dos gêneros Dermatonotus e Phyllomedusa e, sobretudo, contribuem com a compreensão dos processos de diversificação nos biomas abertos da América do Sul.

4
  • MARILIA BRUZZI LION
  • DISTÂNCIA DE DESCONEXÃO, FRAGMENTAÇÃO DE HABITATS E MODOS REPRODUTIVOS NA CONSERVAÇÃO DA HERPETOFAUNA.

  • Advisor : CARLOS ROBERTO SORENSEN DUTRA DA FONSECA
  • COMMITTEE MEMBERS :
  • CARLOS ROBERTO SORENSEN DUTRA DA FONSECA
  • GABRIEL CORREA COSTA
  • MARCIO ZIKAN CARDOSO
  • MILENA WACHLEVSKI MACHADO
  • THIAGO FERNANDO LOPES VALLE DE BRITTO RANGEL
  • Data: Aug 28, 2014


  • Show Abstract
  • O objetivo mais geral desse estudo foi avaliar o efeito de fatores espaciais, paisagísticos e climáticos sobre padrões de comunidades e populações de espécies da herpetofauna. A tese se desdobra em três capítulos:

    O primeiro trata especificamente da distância de desconexão (i. e. a distância que separa fragmentos florestais de fontes de água perenes) e suas implicações para as espécies de anfíbios com larvas aquáticas. Nós mostramos que fragmentos florestais mais distantes de corpo d’água possuem menos espécies e menos indivíduos de anfíbios. Mostramos também que, para os remanescentes atuais da Mata Atlântica, fragmentos maiores são menos afetados pela distância de desconexão e que, portanto, devem ser priorizados em estratégias de conservação.

    O segundo capítulo foca a comunidade e populações de répteis amostradas nos mesmos fragmentos, e avalia o efeito de métricas tradicionais de ecologia de paisagens: tamanho e forma dos fragmentos (na escala local), e isolamento e qualidade da matriz (na escala da paisagem). Ao contrário das previsões teóricas, a riqueza, abundância total e populacional, e a probabilidade de ocorrência das espécies diminuíram com a área dos fragmentos. As demais métricas geraram respostas espécie-específicas. Nós destacamos a importância de pequenos fragmentos florestais para a conservação de répteis da Mata Atlântica.

    O terceiro capítulo é uma análise global sobre a distribuição dos modos reprodutivos terrestres (não afetados pela desconexão de habitat) em anfíbios. Avaliamos a relação entre a proporção de modos terrestres e o clima, e a presença de ambientes lóticos e lênticos. A umidade relativa do ar e a evapotranspiração foram as variáveis mais importantes para os modos terrestres. Assim, a quantidade de água no ar é um fator limitante para essas espécies. Já que modos aquáticos e terrestres sofrem diferentes pressões de seleção, características reprodutivas devem ser consideradas em estratégias eficazes para conservação dos anfíbios.

5
  • ELIANA FARIA DE OLIVEIRA
  • Delimitação de espécies e filogeografia de Cnemidophorus ocellifer na Caatinga

  • Advisor : GABRIEL CORREA COSTA
  • COMMITTEE MEMBERS :
  • ADRIAN ANTONIO GARDA
  • FELIPE GOBBI GRAZZIOTIN
  • GABRIEL CORREA COSTA
  • GUARINO RINALDI COLLI
  • SERGIO MAIA QUEIROZ LIMA
  • Data: Oct 31, 2014


  • Show Abstract
  • As Florestas Tropicais Sazonalmente Secas estão distribuídas em várias manchas disjuntas na região Neotropical, sendo que a maior mancha, a mais isolada e diversa em espécies é o bioma da Caatinga, localizado no nordeste do Brasil. Para entender como se deu a diversificação das espécies da Caatinga é necessário examinar as causas da estruturação filogeográfica em espécies com ampla ocorrência no bioma. O lagarto Cnemidophorus ocellifer é um dos mais comuns na Caatinga, e vários estudos sugerem que esta espécie corresponde à várias espécies crípticas. Através de uma abordagem genética multilocus e o emprego de reconstruções filogeográficas e métodos coalescentes, foi possível reconhecer no complexo C. ocellifer duas espécies crípticas bem suportadas e associadas a duas regiões geográficas distintas da Caatinga. A diversificação dessas espécies ocorreu durante o Pleistoceno, tendo as mudanças ambientais do Quaternário como provável causa do isolamento entre essas duas linhagens. A região centro-norte da Caatinga foi apontada como provável centro de origem de C. ocellifer, enquanto que barreiras geográficas como a Serra do Espinhaço aparentemente impediram o contato secundário entre as espécies já divergidas. Através da modelagem de nicho ecológico e da teoria de circuito, foi possível verificar que a variação genética em C. ocellifer é influenciada pela variabilidade da temperatura que parece modular as taxas de fluxo gênico entre as populações. Condições ambientais do passado foram importantes na formação da diversidade genética atual, sugerindo um atraso na resposta genética. Padrões de diferenciação genética em C. ocellifer foram explicados tanto por isolamento pela distância quanto pelo isolamento por resistência. Neste último caso, diferenças na adequabilidade do nicho e a resistência imposta pelos principais rios foram preponderantes para gerar o padrão atual observado. Os resultados aqui apresentados adicionam novas informações à compreensão dos processos envolvidos na origem e manutenção da diversidade na Caatinga, nas escalas macro e microevolutiva.

6
  • GUILHERME GERHARDT MAZZOCHINI
  • Plant diversity influencing structure and functioning of Caatinga vegetation

  • Advisor : GISLENE MARIA DA SILVA GANADE
  • COMMITTEE MEMBERS :
  • CATERINA PENONE
  • EDUARDO MARTINS VENTICINQUE
  • GABRIEL CORREA COSTA
  • GISLENE MARIA DA SILVA GANADE
  • WOLFGANG W. WEISSER
  • Data: Dec 5, 2014


  • Show Abstract
  • O estudo dos efeitos que a diversidade de espécies pode causar nos processos ecossistêmicos tem crescido vertiginosamente nas últimas duas décadas. Diversos trabalhos experimentais realizados no mundo todo têm demonstrado que uma maior diversidade de plantas contribui para o aumento da produtividade de ecossistemas terrestres. Além disso, esse efeito pode influenciar processos em diversos níveis tróficos, contribuindo assim para a estabilidade dos processos ecossistêmicos a longo prazo. Paralelamente com os estudos do efeito da diversidade, muita atenção tem sido dada para desvendar o papel das características funcionais das espécies no funcionamento dos ecossistemas. Isto porque as características funcionais das espécies têm se mostrado importantes "peças" no entendimento dos efeitos que espécies individuais podem exercer nos ecossistemas e suas respostas ao ambiente. Nesta tese de doutorado eu explorei algumas lacunas de conhecimento dentro dessa área em crescente desenvolvimento conhecida na literatura ecológica como "biodiversidade e funcionamento dos ecossistemas". No primeiro capítulo, eu busquei evidências para mecanismos que podem explicar a relação positiva entre diversidade e funcionamento com foco em cinco mecanismos relacionados às interações entre plantas, tendo como parâmetro de funcionamento a produtividade primária. No segundo capítulo, eu utilizei técnicas para a estimativa de padrões de diversidade em escalas biogeográficas e bases de dados de satélites com longa duração para desvendar se a biodiversidade em escalas macroecológicas promove a estabilidade da produtividade dos ambientes terrestres no semiárido brasileiro. Por fim, o objetivo do terceiro capítulo foi entender como a perda da cobertura vegetal originária do uso da terra por comunidades tradicionais no semiárido brasileiro influenciaria os processos de interações entre plantas e o papel das características funcionais das espécies nessas interações. Acredito que a contribuição individual de cada capítulo preenche lacunas de conhecimento importantes dessa área da Ecologia que ainda se encontra em expansão.

2013
Dissertations
1
  • GUSTAVO BRANT DE CARVALHO PATERNO
  • O PAPEL DE INTERAÇÕES POSITIVAS ENTRE PLANTAS NA REGENERAÇÃO DE ÁREAS DEGRADADAS NA CAATINGA

  • Advisor : GISLENE MARIA DA SILVA GANADE
  • COMMITTEE MEMBERS :
  • GISLENE MARIA DA SILVA GANADE
  • ALEXANDRE FADIGAS DE SOUZA
  • CAMILA DE TOLEDO CASTANHO
  • Data: Feb 8, 2013


  • Show Abstract
  • Interações entre plantas são forças ecológicas importantes na estruturação e composição de comunidades vegetais e podem servir como base teórica para a restauração de áreas degradadas. O presente estudo é dividido em dois experimentos distintos. No primeiro, buscou-se entender: (i) se espécies pioneiras de áreas degradadas da Caatinga facilitam a germinação e o estabelecimento de espécies alvo para a restauração; (ii) se as interações entre plantas facilitadoras e facilitadas são espécie-específicas e se a ontogenia das plantas facilitadas afeta a direção e a intensidade dessas interações. Em uma área de Caatinga degradada no vale do São Francisco, Petrolina – PE, vinte cinco sementes e quatro mudas de cinco espécies alvo foram alocadas em plots pareados, com 8 réplicas cada, em baixo e fora da copa de três espécies pioneiras. A riqueza e a abundância de espécies lenhosas estabelecidas nos mesmos plots também foi amostrada. As espécies facilitadoras afetaram positivamente a diversidade e a composição de espécies da comunidade regenerante. Além disso, aumentaram a probabilidade de germinação e estabelecimento das espécies alvo. Dependendo do estágio ontogenético das espécies alvo as interações mudaram de espécie-específicas para não específicas. No segundo experimento, buscou-se entender como o tamanho da facilitadora e a variação na precipitação influencia as interações de facilitação. Em Macau-RN, 45 indivíduos de M. tenuiflora, com um gradiente de tamanhos, foram selecionados em uma área degradada. Um experimento fatorial em blocos foi implementado com 25 sementes de P. pyramidalis semeadas em plots pareados em todas as combinações dos fatores água e copa. M. tenuiflora e água afetaram positivamente a germinação, o estabelecimento e a sobrevivência de P. Pyramidalis. A espécie facilitadora também afetou positivamente as condições microclimáticas do solo e do ar. A intensidade da facilitação dependeu da interação entre estágio ontogenético, água e tamanho da facilitadora.

     

2
  • GUILHERME SANTOS TOLEDO DE LIMA
  • Sobrevivência de Adultos e Estimativa Populacional da guaracava-de-topete-uniforme Elaenia cristata (Aves: Tyrannidae) em Fragmento de Mata Atlântica no Nordeste do Brasil.

  • Advisor : MAURO PICHORIM
  • COMMITTEE MEMBERS :
  • ALAN LOURES RIBEIRO
  • MARCIO ZIKAN CARDOSO
  • MAURO PICHORIM
  • Data: Feb 26, 2013


  • Show Abstract
  • A sobrevivência de adultos é um parâmetro chave nos estudos de história natural e de demografia das aves, no entanto, apenas ~ 4% das espécies de aves neotropicais residentes têm suas taxas de sobrevivência estimadas. Além disso, pouco se conhece da influência de fatores ambientais e sazonais sobre este parâmetro. Os objetivos deste estudo foram estimar taxas de sobrevivência de adultos, e o tamanho populacional de Elaenia cristata (Aves: Tyrannidae), bem como possíveis variações em curto prazo nesses parâmetros. Durante dois anos, capturamos, marcamos e recapturamos 43 indivíduos adultos em um fragmento de mata de restinga em Parnamirim, RN. Com auxílio do programa MARK, utilizamos os modelos de Desenho Robusto para estimar os parâmetros de interesse. Geramos modelos testando a influência das seguintes covariáveis sobre a sobrevivência: tempo, ciclo reprodutivo e pluviosidade entre seções de captura. As estimativas populacionais foram geradas apenas em função do tempo. De acordo com o melhor modelo, a sobrevivência aparente permaneceu constante ao longo do estudo e o tamanho populacional variou entre as seções. A sobrevivência intra-anual foi estimada em 0,94 ± 0,03, que corresponde a uma probabilidade de sobrevivência anual de 78%. As estimativas populacionais variaram de 24 ± 1,87 indivíduos em novembro/2010, a 15 ± 1,89 em fevereiro/2011. Nossa estimativa de sobrevivência anual para E. cristata está entre as maiores registradas dentre aves tropicais, e contribui com a observação geral de que a sobrevivência anual é maior nos trópicos que no hemisfério Norte. Apesar de associadas a grandes intervalos de confiança, as estimativas populacionais apresentaram diferentes tendências entre 2011 e 2012. Acreditamos que os baixos níveis de precipitação no início de 2012, aliados à presença em grande abundância da espécie migrante Elaenia chilensis, tenham diminuído a oferta de recursos e aumentado a competição interespecífica, provocando uma dispersão de adultos da área de estudo.

3
  • PHOEVE MACARIO
  • SOBREVIVÊNCIA E TAMANHO POPULACIONAL DO TIÊ-PRETO Tachyphonus rufus (AVES: THRAUPIDAE) EM FRAGMENTO DE RESTINGA NO EXTREMO NORTE DA MATA ATLÂNTICA 

  • Advisor : MAURO PICHORIM
  • COMMITTEE MEMBERS :
  • MARCIO ZIKAN CARDOSO
  • MAURO PICHORIM
  • RACHEL MARIA DE LYRA NEVES
  • Data: Feb 27, 2013


  • Show Abstract
  • Ainda que grande avanço tenha acontecido no estudo de parâmetros populacionais em aves, pouco se sabe a respeito de suas variações ao longo do ano e dos fatores que os afetam. A reprodução, por exemplo, é um fator capaz de alterar as taxas de sobrevivência de adultos, uma vez que durante este processo o par reprodutor aloca recursos da própria manutenção para a manutenção da prole, tornando-se mais susceptíveis à predação e doenças. Conhecer esses fatores nos ajuda a entender os mecanismos adotados pelas espécies para manter suas populações. O objetivo deste estudo foi gerar estimativas de sobrevivência e tamanho populacional de Tachyphonus rufus, um passeriforme restrito a América Central e do Sul, testando hipóteses a cerca dos fatores que influenciam esses parâmetros. Através do método de captura-marcação-recaptura geramos estimativas utilizando modelos de Multi-estratos e Desenho Robusto Fechado com o uso do programa MARK. Avaliamos a influência de co-variáveis (tempo, chuva e ciclo reprodutivo) e o efeito de transitórios. O modelo mais parcimonioso admitiu a influencia do ciclo reprodutivo na sobrevivência aparente. Observamos maior sobrevivência na estação não-reprodutiva (92% ± 1%) do que durante a reprodução (40% ± 9%), evidenciando um custo reprodutivo. A sobrevivência anual observada (34%) não corrobora o padrão de altas taxas esperado para os trópicos. O maior tamanho populacional de 55,84 indivíduos em nov/11, se deve ao alto recrutamento de jovens para a população adulta, enquanto o menor (10,01 em mai/12) resultou da entrada em massa de indivíduos de uma espécie competidora. Acreditamos que nossos resultados contribuem para o entendimento da história de vida de aves de regiões tropicais, ainda pouco conhecida. Sugerimos que mais trabalhos como este sejam desenvolvidos nos neotrópicos, em especial no Brasil pela escassez de estudos com esse caráter.

4
  • HONARA MORGANA DA SILVA
  • Ectoparasitos associados a aves em um fragmento de Floresta Estacional Decidual do Rio Grande do Norte, Brasil.

  • Advisor : MAURO PICHORIM
  • COMMITTEE MEMBERS :
  • MAURO PICHORIM
  • MICHEL PAIVA VALIM
  • RENATA ANTONACI GAMA
  • Data: Mar 26, 2013


  • Show Abstract
  • Um amplo número de ectoparasitos pode ser encontrado em associação com aves de todo o mundo, dentre os quais malófagos, ácaros e carrapatos. No Brasil, ectoparasitos de aves ainda são pouco conhecidos, e estudos que envolvam esses sistemas são necessários para ampliar o conhecimento das espécies e contribuir na elucidação de questões chaves na ecologia do sistema parasito-hospedeiro. O presente estudo teve como objetivos investigar a comunidade de ectoparasitos associados a aves de um fragmento de mata no Rio Grande do Norte, sua estrutura e a influência de variáveis ambientais e do hospedeiro; e averiguar preferências de microhábitat pelas espécies de ácaros e malófagos. Foram examinados 172 indivíduos pertencentes a 38 espécies de aves Passeriformes e não-Passeriformes. São reportados novos registros geográficos e associações parasito-hospedeiro ainda não conhecidas para várias espécies de ácaros e malófagos. Com uso de regressões lineares, foi detectada influência significativa da morfologia do hospedeiro sobre riqueza e abundância de malófagos. Com uso de testes de qui-quadrado, foram encontradas variações na frequência de indivíduos com diferentes níveis de infestação de malófagos, conforme o tipo de ninho utilizado pelas espécies de aves e os períodos de seca e chuva na área. Análises de modelos nulos de coocorrência e sobreposição de nicho apontaram alto grau de estrutura das assembleias de ácaros e malófagos, quando comparadas com outros grupos, e preferência no uso de microhábitats pelos táxons identificados. Estes resultados corroboram teorias ecológicas nos sistemas parasito-hospedeiro, contribuem para o conhecimento dos ectoparasitos associados às aves neotropicais e apontam a necessidade de futuros estudos experimentais.

     

     

5
  • PEDRO DE FARIAS CAPISTRANO MACEDO
  • Aspectos ecológicos da dieta de uma comunidade de lagartos da caatinga.

  • Advisor : GABRIEL CORREA COSTA
  • COMMITTEE MEMBERS :
  • ALEXANDRE VASCONCELLOS
  • CARLOS ROBERTO SORENSEN DUTRA DA FONSECA
  • GABRIEL CORREA COSTA
  • GUARINO RINALDI COLLI
  • Data: Jun 21, 2013


  • Show Abstract
  • O tamanho corporal nos animais é uma característica importante que influencia aspectos fisiológicos, morfológicos e ecológicos como, por exemplo, a área de vida e a largura do nicho. É conhecido que existe relação entre o tamanho corporal do predador com as presas capturadas. Trabalhos recentes tem encontrado relação positiva entre o tamanho máximo e mínimo das presas com o tamanho do predador. Esse resultado indica que os predadores maiores comem presas grandes e evitam presas menores. Testei tal relação tamanho predador-presa sob condições de disponibilidade alimentar distintas e entre duas estratégias de forrageio. Coletei invertebrados na estação seca e chuvosa em conjunto com as coletas de lagartos para verificar a disponibilidade de alimentos. Esta não variou entre as estações da área de estudo, porém alguns grupos importantes na dieta dos lagartos foram mais abundantes na estação chuvosa. Fiz também comparações entre a distribuição dos tamanhos das presas no ambiente e na dieta entre estações. Estes mostraram que existiam mais presas grandes na estação seca e que tanto na estação seca quanto na chuvosa os lagartos preferiam a porção de presas maiores disponíveis no ambiente. Então medi o comprimento rostro-cloacal (CRC) dos espécimes de lagartos coletados e fiz uma análise do conteúdo estomacal nos mesmos. Por fim utilizei regressões quantílicas a fim de observar variações entre os limites máximo e mínimo dos volumes das presas em relação ao CRC e se variavam entre as estações e entre estratégias de forrageio. Encontrei que a relação tamanho de predador com o tamanho mínimo da presa não difere entre as estações, rejeitando que a disponibilidade de alimento influencia a seletividade do predador. Enquanto comparações entre as estratégias de forrageio ativo e “senta-e-espera” apresentaram diferenças significativas, confirmando a hipótese que a estratégia de forrageio influência os valores máximo e mínimo para a relação tamanho corporal predador-presa.

6
  • LUCAS VIEGAS FRANCISCO
  • O efeito dos invertebrados aquáticos na decomposição foliar: uma meta-análise

  • Advisor : ADRIANO CALIMAN FERREIRA DA SILVA
  • COMMITTEE MEMBERS :
  • ADRIANO CALIMAN FERREIRA DA SILVA
  • ANDRE MEGALI AMADO
  • LUCIANA SILVA CARNEIRO
  • ALBERT LUIZ SUHETT
  • Data: Jul 4, 2013


  • Show Abstract
  • Até o momento não há um estudo que objetivou sintetizar a magnitude e variação do papel dos invertebrados aquáticos sobre a decomposição do detrito foliar em ambientes aquáticos. Além disso, existe uma falta de conhecimento sobre qual é o impacto geral desses pequenos organismos na decomposição foliar. Além do mais, existe um quantidade de controvérsias sobre como e quais devem ser os fatores mais influentes nesse processo ecológico. O objetivo deste estudo foi através de uma abordagem meta-analítica, entender como estes organismos afetam a decomposição foliar em ecossistemas aquáticos, e como este efeito varia de acordo com aspectos ecológicos e metodológicos. Foram incluídos estudos que avaliaram as taxas de decaimento exponencial na presença e ausência de invertebrados, sendo abordadas apenas as variáveis presentes em mais de 90% dos estudos do banco de dados. Como esperado, a presença dos invertebrados acelera a decomposição foliar e sua magnitude do efeito em escala global é consistente. Este efeito não difere em relação ao tipo de ecossistema (lótico ou lêntico), temperatura ou latitude. Portanto, esta análise contradiz o argumento que invertebrados tem um maior papel na decomposição em ecossistemas de altas latitudes enquanto microrganismos deveriam ser mais importantes mais próximo aos trópicos. Não observou-se nenhum viés ou quanto aos métodos de exclusão dos invertebrados ou ainda quanto a diferença entre as malhas. Apesar de ser difícil afirmar que não existem efeitos aditivos da exclusão experimental ou ainda a diferença entre as malhas. Provavelmente outros parâmetros não foram incluídos nesta análise poderiam explicar o efeito dos invertebrados na decomposição foliar, entretanto um insuficiente número de parâmetros disponíveis dificultam mais avaliações. Esta síntese conclui que o papel acelerador dos invertebrados detritívoros deveria ser incluída em modelos biogeoquímicos. Mais especificamente, estes modelos deveriam incorporar parâmetros como a origem do detrito e a duração experimental.

7
  • ANGÉLICA NAGATA DE SOUSA BORGES
  • Risk assessment’ mechanism: Can tadpole modify its biomass and stoichiometry in response to differences in conspecific density?

  • Advisor : LUCIANA SILVA CARNEIRO
  • COMMITTEE MEMBERS :
  • JOSE LUIZ DE ATTAYDE
  • LUCIANA SILVA CARNEIRO
  • RAFAEL DETTOGNI GUARIENTO
  • Data: Jul 16, 2013


  • Show Abstract
  • Neste estudo, um experimento em mesocosmo foi conduzido para avaliar: (i) o crescimento e o balanço estequiométrico dos girinos de rã-touro (Lithobates catesbeianus), em diferentes densidades, em resposta aos sinais químicos da presença do predador (Belostoma spp) e o; (ii) o efeito indireto da presença do predador sobre o recurso basal (perifíton). Os resultados encontrados mostraram que a presença do predador não induziu mudanças no crescimento e no balanço estequiométrico dos girinos de rã-touro.

8
  • BRUNO GAZOLA DE FARIA
  • ALTERAÇÃO DA QUALIDADE DO SOLO EM ZONA RIPÁRIA SOB DIFERENTES USOS: POTENCIAL DE POLUIÇÃO PARA UM MANANCIAL TROPICAL.

  • Advisor : KARINA PATRICIA VIEIRA DA CUNHA
  • COMMITTEE MEMBERS :
  • KARINA PATRICIA VIEIRA DA CUNHA
  • VANESSA BECKER
  • CLÍSTENES WILLIAMS ARAÚJO DO NASCIMENTO
  • Data: Aug 23, 2013


  • Show Abstract
  • O crescimento demográfico pressiona ambientes intrinsecamente sensíveis a modificações, como as zonas ripárias de mananciais, sem que se conheçam os efeitos da substituição desses ambientes naturais por diferentes usos na qualidade ambiental do solo e, consequentemente da bacia hidrográfica.  O estudo da qualidade ambiental do solo tem evoluído como importante ferramenta para o manejo sustentável deste componente da biosfera que influencia diretamente no funcionamento de ecossistemas terrestre e aquáticos.  Assim, a caracterização de atributos físicos e químicos do solo da zona riparia de uma lagoa tropical sob diferentes usos (Agrícola, Pasto, Vegetação Natural, Urbano e Industrial) foi realizada para avaliar a qualidade ambiental do solo e seu potencial em atuar como fonte difusa de contaminação do manancial. Os dados obtidos foram submetidos à análise de componentes principais (PCA), analise decritiva e correlação.  Os resultados mostraram alterações negativas da qualidade do solo como alcalinização, e aumento dos teores de Pb, Mn e Zn em áreas mais antropizadas. Os teores de Cd no solo foram considerados elevados , sendo maior na área sob Vegetação Natural, o que pode indicar contribuição do material de origem do solo. A substituição da mata nativa na zona ripária da lagoa por usos antrópicos aliada a textura arenosa e o baixo teor de matéria orgânica dessas áreas concorrem para a fragilidade do solo frente à erosão e à lixiviação de nutrientes e metais pesados para os corpos d’água,  o que reforça o potencial desses solos atuarem como fonte difusa de contaminação do manancial.  São necessárias práticas de manejo conservacionistas do solo para a manutenção de um adequado equilíbrio ecológico da zona ripária da lagoa de Extremoz permitindo o controle e mitigação do processo de degradação da qualidade da água desse importante manancial de abastecimento por fontes difusas de contaminação.

9
  • NÍCHOLAS SEBASTIAN AIRES DE ARAÚJO
  • OS EFEITOS DA ESTRUTURA DE HABITAT SOBRE AS COMUNIDADES DE ARANHAS EM UMA FLORESTA DE CAATINGA DO NORDESTE BRASILEIRO

  • Advisor : EDUARDO MARTINS VENTICINQUE
  • COMMITTEE MEMBERS :
  • EDUARDO MARTINS VENTICINQUE
  • MARCIO ZIKAN CARDOSO
  • RICARDO ANDREAZZE
  • Data: Aug 28, 2013


  • Show Abstract
  • A complexidade inerente as comunidades naturais desafia nosso entendimento sobre como o habitat influencia a abundância, a distribuição local e diversidade das espécies. O habitat pode influenciar a estrutura das comunidades de múltiplas maneiras, e elucidar essas relações tem sido um desafio na ecologia. Nesse sentido, a hipótese de heterogeneidade de habitat afirma que um aumento na heterogeneidade do habitat (número de habitas) leva a um aumento na diversidade de espécies na paisagem devido a uma expansão no número de partições das dimensões do nicho. O presente trabalho visa identificar se essa hipótese é válida para as aranhas que habitam uma localidade na Caatinga do nordeste brasileiro. Para isso aranhas cursoriais e arborícolas foram amostradas em 30 parcelas dentro de uma área de Caatinga, paralelamente a tomada de medidas de complexidade ambiental, heterogeneidade de habitat e parâmetros do ambiente, relacionadas com múltiplos aspectos da arquitetura da vegetação e composição das espécies de plantas lenhosas. Regressões múltiplas do tipo Stepwise foram utilizadas para medir que parâmetros ambientais locais melhor explicam a variação na riqueza de aranhas arborícolas e cursoriais. Em seguida, um NMDS (Nonmetric multidimensional scaling) foi utilizado para reduzir o número de variáveis preditoras àquelas mais importantes e que melhor representavam a variação na riqueza de aranhas associada ao ambiente que foram amostradas. Os resultados apontam para uma segregação evidente entre as guildas de aranhas arborícolas e cursoriais, tanto relacionado a que tipo de variáveis ambientais melhor explicam sua variação assim como em relação ao extrato da vegetação que ocupam.

10
  • LAURA MARTINA FERNANDEZ
  • Ajudando aos inimigos: Árvores enfermeiras nativas facilitam a exóticas na invasão de florestas secas brasileiras   

  • Advisor : CARLOS ROBERTO SORENSEN DUTRA DA FONSECA
  • COMMITTEE MEMBERS :
  • CARLOS ROBERTO SORENSEN DUTRA DA FONSECA
  • GISLENE MARIA DA SILVA GANADE
  • SERGIO M. ZALBA
  • Data: Aug 30, 2013


  • Show Abstract
  • Interações positivas entre plantas nativas são forças fundamentais determinantes da estrutura e composição de comunidades em habitats estressantes. Em ecossistemas áridos e semiáridos, as condições microclimáticas fornecidas pelas árvores nativas (“enfermeiras”) são um fator chave, promovendo o estabelecimento de plântulas arbóreas. Escassos estudos avaliam se esse mecanismo beneficia também espécies exóticas. Este trabalho visou testar se árvores exóticas podem ser facilitadas por árvores nativas para invadir o bioma semiárido Caatinga. Realizou-se um experimento na Estação Ecológica do Seridó (RN, Brasil), com um desenho fatorial em blocos, incluindo duas espécies exóticas invasoras importantes Leucaena leucocephala e Prosopis pallida, assim como cinco espécies nativas dominantes Aspidosperma pyrifolium, Combretum leprosum, Croton sonderianus, Poinceianella pyramidalis e Mimosa tenuiflora. Quatro mil sementes das espécies exóticas (alvo) foram semeadas em presença e ausência das plantas enfermeiras. Nós encontramos evidencias de que árvores nativas podem facilitar a invasão de espécies exóticas neste bioma. A presença de enfermeiras reduziu a temperatura do solo incrementando tanto o número de sementes germinadas quanto a altura máxima das plântulas, assim como o número máximo de folhas e a sobrevivência das mesmas. A predação de sementes de L. leucocephala não variou com a presença das árvores nativas, enquanto que a herbivoria média das folhas foi maior dentro da copa, diminuindo a intensidade da facilitação. A intensidade do efeito facilitador foi maior para L. leucocephala do que para P. pallida. Os resultados indicam que a intensidade de facilitação na fase de germinação pode variar dependendo da espécie da planta enfermeira, enquanto que a herbivoria demostrou ser um processo espécie-específico. Todas as plântulas morreram passados sete meses do experimento devido a condições de extrema seca. Por fim conclui-se que as modificações microclimáticas associadas com espécies “enfermeiras” podem ser importantes para o sucesso de germinação e estabelecimento de plântulas de espécies exóticas em ambientes semiáridos, porém em anos secos a facilitação não é suficiente. 

11
  • NILTON LEITE DE SOUSA JUNIOR
  • DYNAMICS OF NUTRIENTS CONCENTRATIONS IN TWO RESERVOIRS OF THE POTIGUAR SEMIARID REGION DURING A PERIOD OF PROLONGED DROUGHT

  • Advisor : JOSE LUIZ DE ATTAYDE
  • COMMITTEE MEMBERS :
  • JOSE LUIZ DE ATTAYDE
  • RONALDO ANGELINI
  • VANESSA BECKER
  • HELIO RODRIGUES DOS SANTOS
  • ALEXANDRE VASCONCELLOS
  • Data: Aug 30, 2013


  • Show Abstract
  • The dams of the semiarid region of Brazil are aquatic ecosystems vulnerable to eutrophication because they usually have a high external load of nutrients and a low rate of water renewal. Given this, this work is intended to test the hypothesis that nitrogen and phosphorus concentrations, phytoplankton biomass and organic carbon concentrations dissolved in the water of the dams increase during the dry season due to the reduced amount of water accumulated in these reservoirs. In order to test this hypothesis, water samples were collected monthly, during the dry season, from May 2012 to February 2013, in the dam located at the Seridó Ecological Station (ESEC) and in the Pocinhos dam, located at the Solidão Farm, both belonging to the city of Serra Negra do Norte, RN. The total phosphorus, orthophosphate and chlorophyll-a concentrations were determined by colorimetry, whilst the total and dissolved nitrogen concentrations, as well as the dissolved organic carbon concentrations, were determined by a Shimadzu® TOC. During the study period, the reservoirs had a decrease in their volume, which caused an increase in nutrient concentrations in line with what was expected. Nevertheless, the phytoplankton biomass showed a pattern of contrasting variation between the two dams: increasing during the dry season in the dam located at the Farm, but decreasing during the same period in the dam located at ESEC. This reduction of phytoplankton biomass in the ESEC dam was due to increased turbidity and possible light limitation. One can conclude that the increase in nutrient concentrations is a necessary condition, but not enough to cause the increase of phytoplankton biomass during the lengthy period of drought typical of the Brazilian semiarid region. Water turbidity is a relevant factor capable of inhibiting phytoplankton growth, even with increased nutrient concentrations. Lastly, the nutrients concentration during prolonged periods of drought in the Potiguar semiarid region (State of Rio Grande do Norte) caused a decrease in water quality, but other factors must be favorable to biomass increase, since, in the present study, high inorganic turbidity in the ESEC reservoir inhibited photosynthetic flowerings due to limited availability of light.

12
  • EMERSON DE MEDEIROS SOUSA
  • Caracterização ecofisiológica de sementes de espécies lenhosas da Caatinga

  • Advisor : GISLENE MARIA DA SILVA GANADE
  • COMMITTEE MEMBERS :
  • GISLENE MARIA DA SILVA GANADE
  • ALEXANDRE FADIGAS DE SOUZA
  • EDUARDO LUIZ VOIGT
  • MAURO VASCONCELOS PACHECO
  • Data: Sep 12, 2013


  • Show Abstract
  • A dormência é uma propriedade inerente às sementes que definem as condições ambientais em que estas são capazes de germinar e sua presença é uma característica adaptativa comum em espécies que habitam regiões semiáridas. Além disso, a capacidade de estabelecimento das plântulas nesses ambientes tem sido relacionada ao tamanho, vigor e características químicas de suas sementes. O presente estudo pretende verificar padrões de dormência e velocidade de germinação (IVG) em espécies arbóreas da Caatinga, explorando como o tamanho da semente influenciaria os processos de germinação, tamanho das plântulas e a alocação de biomassa. Além disso, almeja-se investigar características químicas das reservas, verificando uma possível relação entre seu conteúdo nutricional e o processo de germinação das sementes. Para tanto, foram coletadas sementes de dez espécies arbóreas da Caatinga para a realização dos testes de superação da dormência, germinação e caracterização bioquímica. No geral, os resultados mostram que os tratamentos de escarificação mecânica e química, além do choque térmico influenciaram positivamente a porcentagem e velocidade de germinação em 50% das espécies, sugerindo que estas apresentam algum nível de dormência física em suas sementes. A caracterização bioquímica mostrou a existência de grande quantidade de carboidratos nas sementes de todas as espécies, baixa proporção de proteína, e baixa quantidade de lipídios neutros. Com o uso de regressões lineares, foi demonstrada a existência de relação significativa entre o tamanho da semente e a razão raiz/parte aérea, onde sementes as maiores investiram uma maior quantidade de recursos para o crescimento da raiz. A relação entre o IVG e o teor de açúcares não redutores também se mostrou significativa, de forma que estes compostos tem relação com a manutenção da qualidade fisiológica das sementes. Estes resultados corroboram algumas relações discutidas na literatura para espécies cultivadas, mas que podem ser aplicadas às espécies nativas da Caatinga.

Thesis
1
  • LIGIA MOREIRA DA ROCHA
  • Ecologia humana e manejo participativo da pesca do búzio Anomalocardia brasiliana (Gmelin,1791)(Bivalvia: Veneridae) na Reserva de Desenvolvimento Sustentável Estadual Ponta do Tubarão (RN)

  • Advisor : Alpina Begossi
  • COMMITTEE MEMBERS :
  • ADRIANA ROSA CARVALHO
  • Alpina Begossi
  • RENATO AZEVEDO MATIAS SILVANO
  • RODRIGO SILVA DA COSTA
  • TATIANA SILVA LEITE
  • Data: Feb 28, 2013


  • Show Abstract
  • Áreas Protegidas são criadas para conservar a biodiversidade e manter os recursos pesqueiros. No entanto, muitas vezes envolvem comunidades litorâneas em situação de pobreza e que têm a pesca (e a mariscagem) como principal fonte de alimento e renda. Assim, objetivos econômicos, sociais e de conservação se sobrepõem. Neste contexto, entender o comportamento dos pescadores é essencial, já que são usuários diretos dos recursos marinhos e elos estruturantes no sistema sócio-ecológico formado. Esta pesquisa teve como objetivo entender o sistema formado na mariscagem de Anomalocardia brasiliana (Gmelin, 1791), molusco bivalve com alto valor social no nordeste brasileiro, e propor estratégias de manejo participativo para o mesmo. A pesquisa foi realizada na Reserva de Desenvolvimento Sustentável Estadual Ponta do Tubarão (RDSEPT, RN), onde não havia informações sobre a mariscagem, seguindo o padrão de “invisibilidade” que esta atividade tem no Brasil. Através de entrevistas, monitoramento participativo e acompanhamento da pesca no período de janeiro/2010 a maio/2011, foi possível: a) identificar quem mariscava, b) registrar a pesca (locais, formas de extração, quantidades extraídas, formas de beneficiamento e tempo gasto na atividade), c) analisar sua sustentabilidade, do ponto de vista das famílias, e d) envolver as famílias no levantamento e análise de dados. Com o conhecimento gerado recomenda-se um arranjo institucional participativo para a pesca, envolvendo co-manejo, acordo de pesca, defeso diferenciado e melhorias para a cadeia produtiva do búzio. A partir do envolvimento com outras comunidades marisqueiras foi também possível fazer uma descrição detalhada sobre como a mariscagem acontece no Nordeste brasileiro. Por fim, comparando-se as experiências do projeto Gente da Maré (envolvendo comunidades marisqueiras no Nordeste brasileiro) e da implantação da Reserva Extrativista Marinha do Pirajubaé (SC), foi possível analisar os avanços e as dificuldades existentes nas iniciativas que envolveram co-manejo de A. brasiliana no Brasil.

2
  • ALEXANDER CESAR FERREIRA ROMAN
  • RELAÇÕES ECOLOGICAS ENTRE CARANGUEJOS E COMPOSIÇÃO ARBÓREA EM BOSQUES DE MANGUE NATURAIS E RESTAURADOS NO NORDESTE BRASILEIRO

  • Advisor : JOSE LUIZ DE ATTAYDE
  • COMMITTEE MEMBERS :
  • ALEXANDRE FADIGAS DE SOUZA
  • CARLOS ROBERTO SORENSEN DUTRA DA FONSECA
  • EVERARDO VALADARES DE SÁ BARRETO SAMPAIO
  • JOSE LUIZ DE ATTAYDE
  • LUIS ERNESTO ARRUDA BEZERRA
  • Data: Jul 8, 2013


  • Show Abstract
  • O presente estudo teve como objetivo comparar o desenvolvimento das comunidades de árvores e caranguejos de duas áreas de mangue restauradas, uma plantada com Rhizophora mangle e outra naturalmente recuperada, além de comparar a magnitude da predação do Grapsídeo Goniopsis cruentata e do Ocypodídeo Ucides cordatus sobre os propágulos de três espécies de mangue: Rhizophora mangle, Avicennia schaueriana e Laguncularia racemosa. Em particular, foi testada a hipótese de que a predação de Goniopsis é mais importante que a predação por Ucides e que esses consumidores possuem efeitos antagônicos sobre a predação de propágulos. Em cada área, 10 quadrantes foram aleatoriamente selecionados para analisar a riqueza arbórea, diâmetro, altura, biomassa arbórea e riqueza e densidade de caranguejos cinco anos após o início do experimento de restauração. Os resultados mostraram que tanto a altura e biomassa arbóreas quanto a densidade de caranguejos foram significativamente maiores na área artificialmente restaurada. Não foram observadas diferenças significativas na riqueza de espécies de caranguejos entre as áreas, mas houve uma maior riqueza de espécies de árvores na área auto-recuperada. Estes resultados sugerem que o plantio de propágulos de Rhizophora pode aumentar significativamente a recuperação da cobertura vegetal, se o objetivo for elevar a biomassa arbórea e a densidade de caranguejos, o qual pode acelerar o retorno da funcionalidade ecossistêmica. Goniopsis foi um predador de propágulos mais importante que Ucides tanto em áreas naturais quanto restauradas. Os efeitos de Goniopsis foram maiores na ausência de Ucides devido a interações negativas entre estas espécies de predador. A preferência de Goniopsis por Avicennia e Laguncularia pode favorecer a dominância de Rhizophora observada nos mangues Neotropicais. Este estudo sugere que a predação de propágulos por Goniopsis em programas de restauração de mangue deveria ser controlada se a dominância de Rhizophora é indesejável em relação a comunidades com mais espécies de árvore.

3
  • ELINEZ DA SILVA ROCHA
  • Efeitos do aporte de detritos e nutrientes alóctones sobre estrutura e dinâmica trófica de ecossistemas lacustres tropicais.

  • Advisor : JOSE LUIZ DE ATTAYDE
  • COMMITTEE MEMBERS :
  • JOSE LUIZ DE ATTAYDE
  • LUCIANA SILVA CARNEIRO
  • VANESSA BECKER
  • EVANILDE BENEDITO
  • ROBERTO DE MORAES LIMA SILVEIRA
  • Data: Jul 12, 2013


  • Show Abstract
  • Ecossistemas aquáticos recebem elevada quantidade de subsídios energéticos provenientes de fontes alóctones de detritos e nutrientes. O objetivo deste estudo foi investigar como tais subsídios interagem com peixes onívoros e afetam a estrutura e dinâmica trófica de ecossistemas lacustres tropicais. Os efeitos do aporte de detritos alóctones e da onivoria por peixes filtradores sobre a regulação das comunidades planctônicas foram investigados através de um experimento em 24 mesocosmos, com delineamento fatorial 2x2, onde dois níveis de detritos (com ou sem aporte) foram combinados com dois níveis de peixes (presença ou ausência) e a resposta do plâncton aos tratamentos foi monitorada. Os resultados desse experimento mostram que o  aporte de detritos aumentou a concentração de nutrientes além da biomassa de algas e invertebrados planctônicos através da eutrofização dos mesocosmos. No entanto, o efeito positivo do aporte de detritos sobre a biomassa zooplanctônica foi mais forte na ausência de peixes filtradores. Por outro lado, a presença de peixes filtradores reduziu a biomassa zooplanctônica através da predação e aumentou a biomassa de algas, aparentemente através da ciclagem de nutrientes. Os efeitos do aporte de nutrientes sobre a estrutura trófica dos ecossistemas foi investigada através da análise comparativa de um reservatório eutrófico e outro mesotrófico, de onde foram amostrados indivíduos de 13 espécies de peixes e seus principais itens alimentares para a análise de isótopos estáveis de carbono e nitrogênio. Os resultados demonstram que a posição trófica dos peixes foi em geral menor no reservatório eutrófico do que no reservatório mesotrófico. Além disso, os resultados de um modelo de mistura sugerem que as fontes pelágicas de carbono para os peixes foram mais importantes do que as fontes bentônicas-litorâneas, principalmente no reservatório eutrófico. Portanto, subsídios alóctones de detritos e nutrientes alteram a estrutura trófica dos ecossistemas lacustres com importantes implicações para a dinâmica desses ecossistemas. 

4
  • PABLO ARIEL MARTINEZ
  • ESTUDOS MACROECOLÓGICOS EM CANÍDEOS: UMA PERSPECTIVA NEOTROPICAL

  • Advisor : WAGNER FRANCO MOLINA
  • COMMITTEE MEMBERS :
  • FERNANDO PERINI
  • GABRIEL CORREA COSTA
  • MIGUEL OLALLA-TÁRRAGA
  • SERGIO MAIA QUEIROZ LIMA
  • WAGNER FRANCO MOLINA
  • Data: Aug 28, 2013


  • Show Abstract
  • A observação de padrões fenotípicos em grande escalas geográficas têm levado ao estabelecimento das regras ecogeográficas. Os canídeos em geral possuem uma alta vagilidade, assim como um grande potencial de colonização, sendo estas características acompanhadas por inúmeras variações fenotípicas. Dentro dos canídeos endêmicos da região Neotropical, destacam-se duas espécies por sua ampla distribuição latitudinal, Cerdocyon thous e Lycalopex culpaeus sendo modelos interessantes para estudos Macroeológicos. Analisamos o dimorfismo sexual do tamanho (SSD) na família Canidae, assim como a contribuição ecológica e histórica na variação fenotípica de C. thous e L. culpaeus, a partir de análises de morfometria geométrica, modelos de nicho e filogeografica.  A partir do estudo do SSD observou-se que não seguem a regra de Rensch. Assim também, o SSD na família não está relacionado com a história filogenética, parecendo ser resultado do comportamento monogâmico da família. Cerdocyon thous possui uma distribuição disjunta, encontrando-se populações ao norte e ao sul do Equador. Ao sul do Equador observou-se um clássico padrão de Bergmann, entretanto ao norte do Equador observou-se um padrão inverso à regra de Bergmann. Este padrão inverso, parece ser efeito de processos históricos e não o resultado adaptativo a características ambientais atuais. A partir do estudo de L. culpaeus observaram-se fortes estruturações genéticas. As populações estabelecidas geneticamente também mostraram diferenças significativas na forma do crânio e mandíbula. A forma do crânio e mandíbula parece estar relacionada com a estrutura genética e geográfica das populações. Assim também determinou-se que as variações do tamanho de L. culpaeus mostram um padrão clássico da regra de Bergmann.  A partir de nossos estudos, conseguimos observar padrões gerais de dimorfismo sexual dentro dos canídeos, assim como gerar hipóteses biogeográficas sobre a diferenciação das populações, quantificar a contribuição ecológica e histórica sobre a variação fenotípica de C. thous e L. culpaeus.

5
  • MARINA GOMES VIANA
  • MACROFAUNA DE AMBIENTES NÃO CONSOLIDADOS ADJACENTES A RECIFES DA ÁREA DE PROTEÇÃO AMBIENTAL DOS RECIFES DE CORAIS (RIO GRANDE DO 
    NORTE, BRASIL)


  • Advisor : FULVIO AURELIO DE MORAIS FREIRE
  • COMMITTEE MEMBERS :
  • TATIANA SILVA LEITE
  • ELIANE MARINHO SORIANO
  • LIANA DE FIGUEIREDO MENDES
  • CRISTINA DE ALMEIDA ROCHA BARREIRA
  • PAULO CESAR DE PAIVA
  • Data: Dec 16, 2013


  • Show Abstract
  • Objetivou-se caracterizar os invertebrados bentônicos de regiões infralitorais de fundos inconsolidados adjacentes aos recifes da APARC. As áreas estudadas compreendem bancos vegetados por Halodule wrightii e bancos não vegetados, ambas submetidas a um considerado estresse hidrodinâmico. No geral, foram identificados 6160 indivíduos, distribuídos em 224 espécies sendo poliquetas os mais abundantes (43%) seguido de moluscos (25%) e crustáceos (14%). No primeiro capítulo, focaram-se áreas vegetadas expostas e protegidas à ação das ondas. Foi verificado que a macrofauna do banco exposto apresentou diferenças na estruturação quando comparado ao banco protegido, sendo a granulometria a responsável por estas variações. Foi visto também uma menor variação temporal na estrutura da macrofauna do banco protegido e uma relação negativa entre abundância macrofaunal e peixes bentófagos neste banco. Já no banco exposto, foi verificada uma maior diversidade faunal, em função da maior biomassa de gramínea, que proporcionaria uma maior superfície amostrada. O segundo capítulo aborda uma comparação sazonal entre áreas vegetadas e não vegetadas. Sazonalmente, a complexidade estrutural proporcionada por Halodule discriminou, com mais evidência, a fauna de áreas vegetadas de não vegetadas, somente nas extremidades climáticas. O último capítulo focou áreas não vegetadas a fim de verificar a presença de halo infaunal em recifes tropicais e a influência de peixes bentófagos sobre a macrofauna de bancos submetidos à alto estresse hidrográfico. Tanto a abundância como a estrutura macrofaunal não variaram entre as distâncias da borda recifes. Verificou-se que uma complexa combinação de fatores físicos covariam com a distância da borda e influenciam mais a macrofauna do que os fatores biológicos considerados. Com base nestes resultados, mostro-se que as áreas de fundos inconsolidados do entorno dos recifes da APARC merecem destaque do ponto de vista ecológico e de conservação, pois foram evidenciadas relações importantes da biota com o ambiente e da biota com outros organismos, não descritas antes para estas áreas.

2012
Dissertations
1
  • BRUNNO FREIRE DANTAS DE OLIVEIRA
  • Padrões distintos de congruência climática em duas espécies invasoras de Prosopis em zonas semi-áridas da América do Sul

  • Advisor : CARLOS ROBERTO SORENSEN DUTRA DA FONSECA
  • COMMITTEE MEMBERS :
  • CARLOS ROBERTO SORENSEN DUTRA DA FONSECA
  • ALEXANDRE FADIGAS DE SOUZA
  • GABRIEL CORREA COSTA
  • GUSTAVO HENRIQUE CALAZANS VIEIRA
  • Data: Feb 13, 2012


  • Show Abstract
  • A introdução de espécies exóticas vem crescendo de maneira alarmante devido o aumento da movimentação humana e é considerada um dos fatores que mais influenciam a perda de diversidade biológica atualmente. Modelos de nicho ecológico (MNE) vêm sendo largamente utilizados para prever a distribuição potencial de espécies exóticas, baseados nas informações climáticas dos registros de ocorrência, e fornecem uma importante oportunidade de identificar áreas sob risco ou vulneráveis à invasão.  Estes modelos se baseiam na suposição de que quando calibrados na região nativa existe congruência entre os climas ocupados na região nativa e invadida. Entretanto, nas regiões invadidas as espécies exóticas são capazes de ocupar nichos climáticos que diferem substancialmente do original. Utilizando recentes métodos de medição de sobreposição de MNE, nós testamos a suposição de que P. juliflora (Sw.) D.C. e P. pallida (H. & B. ex. Willd) H.B.K., duas espécies invasoras em regiões áridas e semi-áridas da América do Sul, ocupam nichos climáticos semelhantes na região nativa e na região invadida. Além disso, testamos a hipótese da congruência climática para verificar se os nichos climáticos ocupados nas regiões nativa e invadida de ambas as espécies são congruentes entre si. Nossos resultados indicam que estas espécies respondem diferentemente as variáveis ambientais na região nativa, mas de maneira similar na região invadida. Desta forma, algum fator não climático limita a dispersão de P. pallida na região nativa. As duas espécies apresentaram padrões similares de congruência entre nichos climáticos nativos e invadidos. P. juliflora apresenta conservatismo de nicho, ocorrendo na região invadida em locais climaticamente similares a região nativa, enquanto que P. pallida ocorre em locais similares em parte. Nossos modelos prevêem vários locais climaticamente favoráveis para a ocorrência de ambas as espécies em regiões onde ainda não existem registros de ocorrência, inclusive locais de elevado interesse de conservação.

2
  • UIRANDÉ OLIVEIRA COSTA
  • Determinantes locais da decomposição foliar e de raízes finas em um ecossistema semiárido do nordeste brasileiro

  • Advisor : ALEXANDRE VASCONCELLOS
  • COMMITTEE MEMBERS :
  • ALEXANDRE VASCONCELLOS
  • ANDRE MEGALI AMADO
  • JACOB SILVA SOUTO
  • Data: Feb 22, 2012


  • Show Abstract
  • A decomposição exerce um amplo controle sobre o ciclo do carbono, disponibilidade e ciclagem de nutrientes nos ecossistemas terrestres. A compreensão sobre os padrões de decomposição foliar acima do solo e das raízes finas abaixo do solo é necessária e essencial para identificar e quantificar com mais precisão os fluxos de energia e matéria nos sistemas florestais. Ainda há carência de estudos e uma grande lacuna no conhecimento sobre quais variáveis ambientais atuam como determinantes locais sobre os controladores da decomposicão. O conhecimento sobre o processo de decomposição ainda é incipiente para o semiárido brasileiro. O objetivo do presente estudo foi analisar o processo de decomposição (folhas e raízes), de uma mistura de três espécies nativas durante 12 meses em um ecossistema semiárido do Nordeste Brasileiro. Também foi analisado se a taxa de decomposição pode ser explicada por fatores ambientais locais, especificamente riqueza de espécies, densidade e biomassa aérea vegetal, riqueza de espécies e abundância de macro-artrópodes do solo, produção de serrapilheira e estoque de raízes finas. Trinta pontos amostrais foram distribuídos aleatoriamente dentro uma área de 2000 x 500 m. Para determinação das taxas de decomposição foi utilizada a técnica de bolsas de serapilheira (litterbags) e para as análises dos dados foram utilizadas regressões múltiplas. Houve uma alta degradação da matéria orgânica morta. A biomassa aérea vegetal foi o único fator ambiental local significativamente relacionado à decomposição foliar. A densidade da vegetação e a produção da serrapilheira foram, respectivamente, positiva e negativa significativamente relacionadas com as taxas de decaimento de raízes finas. A heterogeneidade espacial da Caatinga pode exercer fortes influências no processo de decomposição, tendo em vista a atuação de fatores ambientais relacionados à exposição da matéria orgânica e a consequente atuação da radiação solar como controlador do processo de decomposição na Caatinga.

3
  • HEITOR BRUNO DE ARAUJO SOUZA
  • A diversidade de Lagartos na Caatinga é mediada pelos térmitas

  • Advisor : ALEXANDRE VASCONCELLOS
  • COMMITTEE MEMBERS :
  • ALEXANDRE VASCONCELLOS
  • GABRIEL CORREA COSTA
  • WASHINGTON LUIZ DA SILVA VIEIRA
  • Data: Feb 23, 2012


  • Show Abstract
  • Ao tentar explicar a extraordinária taxa de coexistência em taxocenoses de lagartos em desertos australianos, Morton & James (1988) formularam uma hipótese em que a diversidade de térmitas promoveria uma diversificação dos lagartos. O presente trabalho visa verificar se essa hipótese é válida para as taxocenoses de lagartos da Caatinga. Objetiva-se também verificar se os mecanismos de defesa dos térmitas influenciam a taxa com que esses são consumidos pelos lagartos e se esse padrão difere entre diferentes linhagens de lagartos. Para a coleta dos térmitas foi aplicado um protocolo padronizado de amostragem termítica. Para a coleta dos lagartos, além da busca ativa, foram instaladas 108 armadilhas de queda em cada área. Para verificar a relação entre as comunidades de lagartos e térmitas foi analisado o conteúdo estomacal dos lagartos e, em seguida, foi realizada uma Análise de Correspondência Canônica. Posteriormente realizou-se uma análise de sobreposição de nicho.  Para verificar se o mecanismo de defesa dos térmitas influencia o seu padrão de consumo pelos lagartos, realizou-se um experimento onde se ofertou térmitas com diferentes mecanismos de defesa para lagartos de duas linhagens diferentes. Verificou-se que a taxocenose de lagartos não consome os térmitas de acordo com a abundância destes no ecossistema. Além disso, a sobreposição de nicho alimentar não foi menor do que o esperado ao acaso. Verificou-se que o mecanismo de defesa química influencia sim o padrão de consumo dos térmitas pelos lagartos, Esses resultados não corroboram as premissas que alicerçam a hipótese de Morton e James (1988). E indicam que os lagartos não selecionam os térmitas a serem consumidos devido à sua abundância, mas, sim, de modo a evitar térmitas que exibissem mecanismos de defesa química. A presença desse mecanismo de defesa, porém, não seria a única explicação para o padrão de consumo dos térmitas pelos lagartos.

4
  • PRISCILA LINS PIMENTEL FIGUEIREDO DO AMARAL
  • Movimento de borboletas frugívoras e conectividade funcional em uma paisagem de Mata Atlântica

  • Advisor : MARCIO ZIKAN CARDOSO
  • COMMITTEE MEMBERS :
  • EDUARDO MARTINS VENTICINQUE
  • GISLENE MARIA DA SILVA GANADE
  • ONILDO JOÃO MARINI FILHO
  • Data: Apr 5, 2012


  • Show Abstract
  • O movimento de organismos dentro e entre unidades de habitat é um traço essencial da história de vida que molda a dinâmica das populações, comunidades e ecossistemas no espaço e no tempo. Como a habilidade de perceber e reagir às condições específicas de habitat varia grandemente entre os organismos, diferentes padrões de movimento são gerados. Estes, por sua vez, vão refletir na forma com que espécies persistem nos remanescentes de habitat original e de entorno. Este estudo avaliou padrões de movimento de borboletas frugívoras para estimar a conectividade em um mosaico paisagístico em uma área de Mata Atlântica. Para tal foi utilizado o método de Captura-Marcação-Recaptura de borboletas, utilizando armadilhas com iscas de fruta fermentada, em três tipos de habitats. O primeiro, mata, representa as condições normais de um remanescente de Mata Atlântica, ao passo que os outros dois representam matrizes antropogênicas, contendo plantação de coqueiro em uma delas e plantação de uma árvore exótica (Acacia mangium). Cinco armadilhas foram aleatoriamente colocadas em cada unidade da paisagem em áreas de 40 x 40m. Usando dados de frequência de captura de borboletas e relacionando com dados de distância entre armadilhas e estrutura dos habitats, encontrei que as frequências de movimento, tanto dentro quanto entre unidades da paisagem são diferentes para as espécies analisadas, indicando que as mesmas não parecem sentir e reagir à paisagem da mesma maneira. Assim, este estudo conseguiu medir conectividade funcional na paisagem. Para a maioria das espécies, as trocas entre mata e coqueiral ocorreram com baixa frequência, em comparação às trocas entre mata e acácia, que compartilham mais semelhanças estruturais. Os resultados sugerem que uma matriz mais similar a manchas de vegetação nativa pode abrigar espécies, ser permeável ao movimento e, consequentemente, contribuir para conectividade da paisagem.

5
  • FRANÇOISE DANTAS DE LIMA
  • Dinâmica populacional e aspectos reprodutivos do Octopus insularis (Cephalopoda: Octopodidade): implicações para o manejo da pesca de polvo no município de Rio do Fogo - RN

  • Advisor : TATIANA SILVA LEITE
  • COMMITTEE MEMBERS :
  • ADRIANA ROSA CARVALHO
  • MANUEL HAIMOVICI
  • TATIANA SILVA LEITE
  • Data: Apr 12, 2012


  • Show Abstract
  • No Nordeste Octopus insularis é a espécie de polvo de maior importância comercial e sua captura tem sido realizada durante muitos anos pelos mesmos pescadores de lagosta da região como um incremento à renda. Pelo fato de ser uma espécie recentemente descrita, pouco ainda se conhece sobre a biologia e ecologia deste animal na região costeira do nordeste brasileiro, uma vez que os principais trabalhos científicos foram realizados nas ilhas oceânicas. Visando obter informações a respeito da biologia reprodutiva para subsidiar a elaboração de estratégias de manejo dessa espécie, foram realizadas amostragens na região de Rio do Fogo, das quais se obtiveram dados para determinação do tamanho e peso mínimo de maturação de machos e fêmeas e as épocas de maior atividade reprodutiva dos polvos. Também foi realizada a primeira descrição macro e microscópica do processo de maturação para O. insularis. Ao final do trabalho fica evidente que as estratégias de conservação e manejo aplicadas ao O. insularis devem diferir daquelas aplicadas ao O. vulgaris, espécie abundante na região sul do Brasil, pois essas espécies possuem características morfológicas, ecológicas e reprodutivas diferentes.

     

6
  • ALLAN TORRECILLA BATISTA
  • Caracterização do nicho alimentar do polvo Octopus insularis: da população ao indivíduo 

  • Advisor : TATIANA SILVA LEITE
  • COMMITTEE MEMBERS :
  • ARRILTON ARAUJO DE SOUZA
  • TATIANA SILVA LEITE
  • GUNVOR ØIE
  • Data: Apr 18, 2012


  • Show Abstract
  • Octopus insularis, espécie alvo deste estudo, é o polvo bentônico dominante das regiões Norte e  Nordeste do Brasil. Estudos sobre comportamento e ecologia da espécie tem sido realizados prioritariamente em ilhas oceâncias, com poucas informações sobre as populações continentais. No presente estudo, duas regiões da costa do RN, Rio do Fogo e Pirangi, foram escolhidas para a caracterização do nicho ocupado pelas populações de O. insularis. Os nichos alimentares, habitat e distribuição do O. insularis das ilhas oceânicas e do continente, foram comparados. Adicionalmente, características individuais do comportamento alimentar em uma população do Atol das Rocas foi estudada, levando em consideração o tamanho do individuos e caracteristicas da sua “personalidade”. A dieta da população de Rio do Fogo foi composta principalmente por moluscos bivalves (82%), diferentemente da população Pirangi que possui uma dieta composta principalmente por crustáceos decápodas (68%), similar ao descrito para as populações das ilhas. Consequentemente, os nichos alimentares das populações das ilhas foram mais próximos, com maior sobreposição, porém a largura do nicho no continente foi maior.  Os habitas de ocorrência da espécie na costa inclui recifes, rochas, cascalho e uma ambiente denominado restinga, um plato biogênico composto por cascalho, areia, esponjas e algas, onde foi encontrada uma alta densidade de animais. De modo similar ao encontrado nas ilhas, os polvos no continente, apresentaram um distriuição agrupada, e uma segregação entre indivíduos pequenos e grandes, em relação a profundidade e ao habitat As diferenças na composição da dieta entre as populações foi explicada pela difereças nos habitats e cobertura do substrado, que podem estar influenciando diretamente na diversidade e disponibilidade de presas nestes ambientes. As análises individuais da população do Atol das Rocas, não apontaram diferenças nos graus de especialização entre indivíduos de diferentes tamanhos e com diferentes personalidades, indicando a tendência à uma estratégia de forrageio com prioridade pela presa com maior disponibilidade no ambiente em detrimento à preferências ou capacidades de aprendizado individuais.

7
  • RODRIGO XAVIER SOARES
  • Padrões cromossômicos e mapeamento de genes ribossomais 18S e 5S em peixes pelágicos Atlânticos

  • Advisor : WAGNER FRANCO MOLINA
  • COMMITTEE MEMBERS :
  • WAGNER FRANCO MOLINA
  • LILIANE DE LIMA GURGEL
  • LUCIA GIULIANO CAETANO
  • Data: Apr 27, 2012


  • Show Abstract
  • Os estudos citogenéticos em peixes vêm contribuindo significantemente para um melhor conhecimento sobre a biodiversidade marinha, apresentando informações voltadas à caracterização, evolução e conservação de espécies/estoques pesqueiros. Entre as espécies marinhas cujos dados citogenéticos são menos conhecidos se destacam as formas pelágicas, que apesar da importância econômica e de esforços conservacionistas vêm sofrendo grande pressão da pesca artesanal e industrial. O presente trabalho caracterizou citogeneticamente seis espécies de grandes peixes pelágicos no Atlântico, pertencentes à Ordem Perciformes, dentre elas, quatro espécies de Scombridae, Thunnus albacares, T. obesus, Scomberomorus brasiliensis e Acanthocybium solandri e as duas de Coryphaenidae, Coryphaena equiselis e C. hippurus utilizando métodos citogenéticos clássicos, como coloração convencional, bandamento C e Ag-RONs, e moleculares, através da coloração com fluorocromos AT e GC-específicos e mapeamento de famílias multigênicas ribossomais 18S e 5S. A identificação de padrões filogenéticos e marcadores citotaxonômicos entre as espécies e a presença de cromossomos sexuais em pelo menos uma espécie de Coryphaenidae, são particularmente úteis na formulação de hipóteses filogenéticas, bem como em comparações entre grupos e populações.

8
  • GINA RODO MANTILLA
  • Taxa de alimentação e Ingestão Nutricional do Callithrix jacchus: relação com fatores ambientais e sociais

  • Advisor : ARRILTON ARAUJO DE SOUZA
  • COMMITTEE MEMBERS :
  • ARRILTON ARAUJO DE SOUZA
  • MARIA DE FATIMA ARRUDA DE MIRANDA
  • REGINA HELENA FERRAZ MACEDO
  • Data: Apr 27, 2012


  • Show Abstract
  • A sazonalidade dos recursos alimentares influencia a ecologia comportamental alimentar de Callithrix jacchus. Como o consumo de alimento está relacionado a necessidades metabólicas e nutricionais, espera-se que a dieta dos sagüis envolva a ingestão balanceada de nutrientes. Contudo, relações de dominância e subordinação resultam em disparidade quanto aos benefícios alimentares. Além disso, foi visto que um item alimentar aparentemente não importante em termos de proporção de tempo de alimentação pode ter elevada concentração de nutrientes ou energia e, portanto, um papel importante na dieta. Este trabalho buscou estimar a ingestão alimentar, a taxa de alimentação e a ingestão nutricional do Callithrix jacchus e relacionar com variações em recursos alimentares, relações de dominância e com o estágio reprodutivo da fêmea dominante. Um grupo de sagüis foi acompanhado por 6 meses, na FLONA Assu/RN, remanescente de caatinga. Registros de ingestão alimentar e de relações socais foram feitos através do método focal animal de dias completos com registro contínuo. Dados sobre as disponibilidades de alimento no ambiente forma coletados mensalmente. E amostras dos recursos consumidos foram coletadas para análise nutricional. Um índice que posiciona membros do grupo em hierarquia de dominância, David’s Score calculado para cada animal. Resultados preliminares demonstram que o comportamento alimentar diferenciado entre os indivíduos pode ser reflexo das relações de dominância Em geral, indivíduos dominantes têm prioridade de acesso ao alimento, roubam mais alimento e tem menos alimento roubado enquanto subordinados tem acesso restrito a itens alimentares sendo limitados a fontes alternativas de alimentação. A ingestão alimentar da fêmea dominante é influenciada tanto pela necessidade nutricional de cada estágio reprodutivo quanto pela composição nutricional do alimento.

9
  • MONALISA RODRIGUES OLIVEIRA DA SILVA
  • ANÁLISE DA RESILIÊNCIA SÓCIO-ECOLÓGICA EM UNIDADES DE CONSERVAÇÃO DE USO SUSTENTÁVEL: SUBSÍDIOS PARA O MANEJO DA PESCA ARTESANAL NO BRASIL


  • Advisor : PRISCILA FABIANA MACEDO LOPES
  • COMMITTEE MEMBERS :
  • PRISCILA FABIANA MACEDO LOPES
  • TATIANA SILVA LEITE
  • RENATO AZEVEDO MATIAS SILVANO
  • Data: May 17, 2012


  • Show Abstract
  • O uso da biodiversidade pelo homem leva a alterações no funcionamento dos ecossistemas, podendo ainda levar a perda de resiliência. Pode-se definir resiliência como a capacidade de um sistema absorver um distúrbio e reorganizar-se, enquanto submetido a mudanças, mantendo a mesma estrutura e funcionamento. Em um sistema social, entende-se como a capacidade dos usuários de recursos naturais de enfrentar e adaptar-se as mudanças nas regras que regem o uso e acesso a estes. Alterações na resiliência, tanto ecológica quanto social, podem ser resultantes das ações de exploração e manejo destes recursos. Assim, torna-se essencial compreender como funcionam as estratégias de manejo e sua interação com a resiliência sócio-ecológica, permitindo a auto-avaliação das ações e possíveis modificações das mesmas. Neste projeto, propõe-se comparar a resiliência sócio-ecológica de três Unidades de Conservação (UCs) de uso sustentável: Reserva de Desenvolvimento Sustentável (RDS) Ponta do Tubarão, localizada no estado do Rio Grande do Norte; e as Reservas Extrativistas do Batoque e Prainha do Canto Verde, ambas localizadas no estado do Ceará. Em cada área de estudo serão escolhidas comunidades pesqueiras, permitindo a comparação entre elas. A partir destas comunidades, alguns aspectos relacionados ao uso dos recursos serão analisados, como atividade pesqueira, dieta e modo de vida. Os dados serão coletados através de questionários semi-estruturados, contendo questões baseadas em aspectos sociais, econômicos e ecológicos. Os resultados obtidos servirão de indicadores para a resiliência ecológica (informações obtidas com base na atividade pesqueira) e social (informações obtidas com base no acompanhamento da dieta e análise do modo de vida). Apesar da similaridade ecológica entre as áreas de estudo, algumas estratégias de manejo distintas em função da categoria da UC podem apresentar diferentes resultados sobre a resiliência sócio-ecológica. Desta forma, compreender como a resiliência sócio-ecológica se comporta, dentro dos sistemas de manejo estudados, permitirá avaliar a influência destes dois tipos de UCs (RDS e RESEX) na promoção da sustentabilidade ecológica e/ou social.

10
  • IZABEL MARIA MATOS DE SOUZA
  • Monitoramento de corais após severo branqueamento e dinâmica entre espécies.


  • Advisor : LIANA DE FIGUEIREDO MENDES
  • COMMITTEE MEMBERS :
  • BÁRBARA SEGAL RAMOS
  • LIANA DE FIGUEIREDO MENDES
  • TATIANA SILVA LEITE
  • Data: Jun 18, 2012


  • Show Abstract
  • O branqueamento de corais tem sido o foco de um número crescente de estudos em todo o mundo desde a década de 1980. O fenômeno tem sido amplamente relacionado a anomalias térmicas das águas superficiais do oceano, especialmente durante períodos de El Niño. No Brasil vários eventos foram registrados a partir de 1993, principalmente em recifes do estado da Bahia. No litoral do estado do Rio Grande do Norte registrou-se branqueamento em massa de corais nos recifes da Área de Proteção Ambiental dos Recifes de Corais (APARC) em março e abril de 2010, quando a temperatura da água atingiu valor de 34°C durante vários dias e cerca de 80% dos corais do complexo recifal de Maracajaú apresentaram-se parcial ou totalmente branqueados. Os objetivos deste trabalho foram avaliar o recobrimento de corais no Parracho de Maracajaú e verificar a dinâmica de branqueamento das espécies. A cobertura de corais foi levantada de acordo com o protocolo Reef Check Brasil associado ao método de quadrado de 0,5 m 2 . A caracterização da dinâmica de branqueamento foi avaliada a partir de registros quinzenais da porcentagem de superfície branqueada em cada uma das 80 colônias monitoradas das espécies Favia gravida, Porites astreoides, Siderastrea stellata e Millepora alcicornis. Simultaneamente ao branqueamento foram registrados os parâmetros abióticos: temperatura da água, pH, salinidade e transparência horizontal. Registrou-se também a ocorrência de eventos caracterizados como indícios de doenças.  Os dados foram submetidos a análises univariada e multivariada sob a perspectiva do conceito do time lag para encontrar possíveis padrões de relação entre a elevação/diminuição da média de branqueamento, a variação dos parâmetros ambientais e a ocorrência de doenças. Os resultados indicam que a temperatura foi o principal fator associado ao aumento das médias de branqueamento, e as espécies exibiram dinâmicas similares com respostas significativamente diferentes (p < 0,05). 

11
  • LEONARDO HENRIQUE TEIXEIRA PINTO
  • Dunas Costeiras de Jenipabu: Status de Conservação e Diretrizes para Restauração da Vegetação

  • Advisor : GISLENE MARIA DA SILVA GANADE
  • COMMITTEE MEMBERS :
  • EDUARDO MARTINS VENTICINQUE
  • GISLENE MARIA DA SILVA GANADE
  • JULIETA BENÍTEZ-MALVIDO
  • Data: Jul 2, 2012


  • Show Abstract
  • Dunas desempenham importantes funções ecossistêmicas, além de seu grande valor estético para atividades turísticas. Em função de sua fragilidade e alto grau de degradação, programas de restauração de vegetação de Duna são fundamentais para preservar este ecossistema. Métodos de restauração descritos para dunas possuem poucas informações científicas sobre os processos ecológicos que controlam a estrutura da comunidade vegetal. Nesse trabalho, investigamos se a facilitação pela vegetação seria um importante processo de controle da sobrevivência e crescimento das plantas transplantadas e em que medida essa influência pode ser imitada pelo uso de malha vegetal. O estudo foi conduzido na Área de Proteção Ambiental Jenipabu (APAJ), RN - Brasil. Para testar os efeitos de facilitação e as técnicas de retenção de areia sobre a sobrevivência de plantas colonizadoras, foram realizados dois experimentos de campo. Sessenta e quatro mudas de Canavalia maritima foram transplantadas para uma área de duna degradada. O delineamento experimental tentou testar os efeitos da vegetação e o uso de malha vegetal sobre o crescimento e a sobrevivência das plântulas. O segundo experimento (estabelecido em parcelas fora da vegetação) procurou testar as técnicas para a expansão lateral da vegetação, comparando o estabelecimento de sementes germinadas (400) e plantas de C. maritima transplantadas (40). Extrema mortalidade de plântulas ocorreu devido a fatores como soterramento por areia, atropelamento e seca. A sobrevivência das plantas foi afetada pela presença da vegetação e a taxa de germinação de sementes foi positivamente influenciada pelo tratamento de pré embebição. Podemos concluir que, apesar da dificuldade de restauração de dunas costeiras, existem evidências do processo de facilitação atuando sobre a estabilização do solo e, também, sobre as condições abióticas, gerando melhoramento microclimático. Além disso, a utilização de sementes juntamente com mudas transplantadas poderia acelerar a restauração da vegetação das dunas.

12
  • KAROL LYNCOLN B DE O DE FRANCA
  • Padrões de coexistência e utilização do hábitat por duas espécies de Herpsilochmus (Aves: Thamnophilidae)

  • Advisor : GABRIEL CORREA COSTA
  • COMMITTEE MEMBERS :
  • ALEXANDRE FADIGAS DE SOUZA
  • GABRIEL CORREA COSTA
  • MAURO PICHORIM
  • MIGUEL ÂNGELO MARINI
  • Data: Jul 5, 2012


  • Show Abstract
  • A coexistência de espécies aparentadas sempre levantou bastante interesse na comunidade cientifica. Isso porque, espécies aparentadas são esperadas coexistir mais que o acaso, divido compartilharem traços similares por relações filogenéticas (conservatismo do nicho) e/ ou convergências adaptativas (filtro ambiental). No entanto, a teoria da exclusão competitiva prevê justamente o oposto, uma menor probabilidade de coexistência justamente entre espécies que possuam uma alta similaridade ecológica. O conhecimento de como essas forças atuam nas comunidades pode revelar quais estratégias são utilizadas para a manutenção da coexistência, trazendo importantes informações para o manejo e conservação das espécies. Neste estudo utilizamos este plano de fundo para testar hipóteses de coexistência entre H. pectoralis e do H. sellowi através de modelos de nicho ecológico em uma alta resolução (50 x50 m). Identificando quais os fatores ambientais estudados melhor predizem a ocorrência das espécies. Utilizando ainda, o ENFA para testar se o H. pectoralis (espécie maior) é realmente menos seletiva que o H. sellowi (espécie menor) como previsto na literatura para outras espécies. Nossos resultados rejeitam a equivalência ecológica entre as espécies, revelando que os Herpsilochmus exploram o habitat de forma diferenciada, possuindo nichos ambientais distintos. A hipótese do conservatismo de nicho não foi evidenciado em nossas análises, sendo a similaridade observada entre os modelos menor que o acaso. Evidências de que os Herpsilochmus estão segregando espacialmente reforça a hipótese da competição interespecífica como força predominante na seleção de microhabitat das espécies. No entanto, para afirmar categoricamente que o padrão observado é efeito de uma competição atual ou passada experimentos futuros são sugeridos.

13
  • IGOR GALVAO DE BRITTO
  • A perda de grupos funcionais em comunidades virtuais: efeito das interações entre espécies e grupos funcionais

  • Advisor : CARLOS ROBERTO SORENSEN DUTRA DA FONSECA
  • COMMITTEE MEMBERS :
  • CARLOS ROBERTO SORENSEN DUTRA DA FONSECA
  • GILBERTO CORSO
  • MÁRIO ALMEIDA NETO
  • Data: Aug 27, 2012


  • Show Abstract
  • Os níveis elevados de extinções locais, regionais e globais tem simplificado progressivamente comunidades e ecossistemas em termos de espécies e funcionamento. Os modelos de predição do grau de funcionamento ecossistêmico após extinções não consideram interações entre espécies ou grupos funcionais, apesar da importância potencial desses parâmetros. Neste estudo, testamos o efeito de diferentes padrões de interações interespecíficas e de grupos funcionais sobre a resistência de comunidades à perda de grupos funcionais. Comunidades virtuais foram construídas com diferentes padrões de distribuição de espécies nos grupos funcionais, tanto com alta quanto com baixa equitabilidade. Uma matriz foi criada para representar o efeito líquido das interações interespecíficas entre todas as espécies, representando padrões de aninhamento, modularidade, espécies sensíveis ou dominantes. Além disto, uma segunda matriz foi criada para representar as interações entre grupos funcionais, tendo também diferentes padrões. A probabilidade de extinção de cada espécie foi calculada com base no somatório das interações sobre ela e sobre o grupo ao qual pertence, modificando também a chance de cada grupo funcional perder espécies e, consequentemente, de permanecer. Realizou-se extinções aleatórias sucessivas até toda a comunidade ser extinta. Pela média de 1000 comunidades seguindo um mesmo padrão, geramos uma média do número de grupos funcionais remanescentes a cada evento de extinção. Encontramos variações notáveis na resistência das comunidades quando as interações eram concentradas sobre alguns grupos funcionais. Cenários com espécies sensíveis geralmente apresentaram maior variação que os demais. Nossos resultados também indicam que as interações podem ser indiferentes ou desestabilizar comunidades com alta equitabilidade, mas não estabilizá-la. Constatamos que a concentração de interações pode aumentar a resistência das comunidades quando ela compensa as diferenças em redundância funcional ou reduzí-la quando acentua-as.

14
  • FABRICIO RODRIGUES CAMACHO
  • O elo microbiano como alimento alternativo para o zooplâncton em reservatórios dominados por cianobactéria

  • Advisor : RENATA DE FÁTIMA PANOSSO
  • COMMITTEE MEMBERS :
  • ENEIDA MARIA ESKINAZI-SANT'ANNA
  • RENATA DE FÁTIMA PANOSSO
  • VANESSA BECKER
  • Data: Aug 31, 2012


  • Show Abstract
  • Protozoários podem ser uma importante fonte alternativa de alimento para copépodos Calanoida em ambientes dominados por cianobactérias. Com o objetivo de quantificar a preferência alimentar de Notodiaptomus cearensis por ciliados em presença de cianobactérias, experimentos in vitro foram conduzidos, utilizando-se culturas mistas em diferentes concentrações totais de alimento para o copépodo. Duas espécies de ciliados (Paramecium sp. e Cyclidium sp.) e uma cepa tóxica de cianobactéria (Microcystis aeroginosa) foram ofertados como alimentos. Experimentos prévios visando identificar os tipos de resposta funcional quando cada uma das presas é ofertada separadamente também foram realizados. Resposta funcional do tipo III foi identificada para todas as presas testadas, apresentando maior taxa de ingestão máxima quando ciliados são ofertados como presa. N. cearensis apresentou preferência significativa por protozoários em detrimento da cianobactéria testada tanto em tratamentos com menor (correspondendo a cerca de 95,15% da dieta) quanto com maior concentração de alimento (cerca de 91,56% da dieta), preferindo o maior ciliado na menor concentração (67,52% da dieta). A participação significativa de detritívoros na dieta do zooplâncton dá maior ênfase à participação da alça microbiana na passagem de energia para níveis tróficos superiores. Tal dado colabora para o entendimento da estabilidade das interações tróficas existentes em reservatórios sujeitos a eutrofização e auxilia estudos de cascata trófica nesses ambientes.

15
  • DANIEL DE OLIVEIRA
  • EFEITOS DAS VARIÁVEIS AMBIENTAIS LOCAIS SOBRE A ABUNDÂNCIA, A RIQUEZA E A BIOMASSA DA MACROFAUNA DE SOLO EM UM ECOSSISTEMA SEMIÁRIDO DO NORDESTE BRASILEIRO

  • Advisor : ALEXANDRE VASCONCELLOS
  • COMMITTEE MEMBERS :
  • ALEXANDRE VASCONCELLOS
  • GINDOMAR GOMES SANTANA
  • RICARDO ANDREAZZE
  • Data: Aug 31, 2012


  • Show Abstract
  • A macrofauna de solo está sujeita aos diversos fatores ambientais bióticos e abióticos, desde variações no ambiente físico à variedade de interações entre as espécies envolvidas, afetando os padrões de biodiversidade da fauna de solo. A heterogeneidade espacial da Caatinga pode ter efeitos fortes sobre a fauna de solo. Este estudo teve como objetivo investigar os efeitos das variáveis ambientais locais sobre os parâmetros biológicos (riqueza de táxons, abundância de indivíduos e biomassa) da macrofauna de solo em um fragmento de Caatinga no município de João Câmara, Rio Grande no Norte, Brasil. Foi traçada uma grade de 2000m x 500m na área de estudo, e posteriormente, foram sorteados aleatoriamente 30 pontos de coleta. A metodologia usada para a coleta da macrofauna foi o método TSBF. Foram testados os efeitos de 10 variáveis ambientais sobre a macrofauna ao longo das parcelas e ao longo das camadas de solo. Os parâmetros biológicos da macrofauna de solo por parcela não sofreram efeitos das variáveis ambientais. A abundância da macrofauna por camada teve influencia positiva da camada de solo e da biomassa vegetal aérea.  A biomassa da macrofauna por camada teve influencia positiva do estoque de raízes finas. A riqueza da macrofauna por camada teve influencia apenas da camada de solo. A biomassa vegetal aérea libera necromassa vegetal que se acumula na camada de superfície, constituindo uma importante fonte de recurso e de abrigo para a macrofauna de solo, explicando sua maior abundância nessa camada. As raízes servem como via para a chegada ao solo de nutrientes provenientes da produção vegetal, dessa forma, uma maior quantidade de raízes condiciona maior entrada de alimento para a macrofauna, principalmente os herbívoros.

16
  • ANA CLÉZIA SIMPLÍCIO DE MORAIS
  • EFEITOS INDIVIDUAIS E INTERATIVOS DA DIVERSIDADE DE DETRITOS, CONTEXTO E VARIABILIDADE AMBIENTAL SOBRE A MAGNITUDE E ESTABILIDADE DO PROCESSO DE DECOMPOSIÇÃO

     

  • Advisor : ADRIANO CALIMAN FERREIRA DA SILVA
  • COMMITTEE MEMBERS :
  • ADRIANO CALIMAN FERREIRA DA SILVA
  • ANDRE MEGALI AMADO
  • FRANCISCO DE ASSIS ESTEVES
  • LUCIANA SILVA CARNEIRO
  • Data: Sep 10, 2012


  • Show Abstract
  • Estudos sobre os efeitos de alterações da biodiversidade para o funcionamento dos ecossistemas tem sido um tema central na ecologia ao longo das duas últimas décadas. Vários trabalhos têm demonstrado que a diversidade de detrito vegetal afeta diferentemente o processo de decomposição em ambientes aquáticos e terrestres, mas sua abordagem em contextos ambientais flutuantes é uma questão não testada dentro do debate de biodiversidade e funcionamento de ecossistemas. Para avaliar se o contexto ambiental, bem como a dinâmica de sua alternância, influenciam os efeitos da diversidade de detrito sobre o processo de decomposição, foi realizado um experimento onde manipulamos a diversidade de detrito foliar de 8 espécies de plantas terrestres decompondo (litterbags) em monoculturas individuais e em mistura contendo as 8 espécies juntas, em três contextos ambientais distintos: ambiente terrestre (T); ambiente aquático (A) e interface (I) - tratamento experimental que simula a condição variável do regime de alagamento. Medimos a taxa de decomposição através da perda de massa da comunidade e de cada detrito individual nas monoculturas e nas misturas. Não foi verificado efeito da riqueza de espécies e nem da variabilidade ambiental sobre a magnitude e estabilidade do processo de decomposição. No entanto, houve efeitos espécie-específicos da diversidade sobre a decomposição da espécie exótica F. benjamina. O contexto ambiental exerceu efeito individual sobre o processo de decomposição, sendo a decomposição mais rápida no ambiente aquático, seguida da interface e mais lenta no ambiente terrestre. Nossos resultados sugerem que é necessário considerar o potencial de outros fatores abióticos capazes de afetar as taxas de processos tanto quanto os efeitos da diversidade.

17
  • LEIDE AMARA PEREIRA DA SILVA
  • Efeitos de florações de cianobactérias sobre os cladóceros Ceriodaphnia dubia e Daphnia gessneri

  • Advisor : RENATA DE FÁTIMA PANOSSO
  • COMMITTEE MEMBERS :
  • ALOYSIO DA SILVA FERRÃO FILHO
  • LUCIANA SILVA CARNEIRO
  • RENATA DE FÁTIMA PANOSSO
  • Data: Sep 25, 2012


  • Show Abstract
  • Florações de cianobactéras são frequentes em reservatórios eutróficos do semi-árido do nordeste brasileiro. Diante dessa realidade o presente trabalho objetiva analisar o efeito de florações de cianobactérias potencialmente tóxicas comuns no reservatório Gargalheiras (semi-árido do RN) sobre os cladóceros Ceriodaphnia dubia e Daphnia gessneri.Foram realizados testes crônicos in vitro com diluições de água do reservatório de agosto/2011 a maio/2012 e foram avaliados: taxa intrínseca de crescimento populacional (r), parâmetros de fecundidade (idade da primeira reprodução, tamanho da ninhada e fecundidade per capita) e movimentos natatórios. O fitoplâncton foi dominado por Cylindrospermopsis raciborskii e Planktothrix agardhii e houve detecção de saxitoxina e microcistina na água. Na maioria dos meses C. dubia apresentou diferença estatística em r entre controle (ausência de cianobactérias) e tratamentos, além de ter apresentado efeitos negativos nos parâmetros de fecundidade. Observou-se ainda um efeito de paralisia dos movimentos natatórios em todos os meses, concomitante à presença de C. raciborskii e saxitoxina (cianotoxina neurotóxica). A C. dubia apresentou-se sensível à água do reservatório contendo cianobactérias. Já a D. gessneri não apresentou efeitos negativos em r nem nos movimentos natatórios e, no geral, os parâmetros de fecundidade não foram negativamente afetados. Esses resultados apoiam a hipótese levantada na literatura de que D. gessneri apresenta resistência aos efeitos da Cylindrospermopsis. A história limnológica dos clones pode ser uma chave para compreensão dos resultados. O clone de C. dubia, isolado de ambiente eutrofizado, está em laboratório há dez anos e essa é uma espécie exótica no Brasil. D. gessneri é comum no país e há um ano foi isolada do reservatório Gargalheiras, onde são constantes as florações de cianobactérias potencialmente tóxicas. Talvez o contato recente com cianobactérias explique a maior resistência às cianobactérias apresentada pela Daphnia. Conclui-se que os cladóceros estudados apresentam diferentes níveis de sensibilidade às cianobactérias, caracterizando respostas espécie-específicas.

18
  • MAÍRA FONTES MANZAN
  • Etnobiologia do boto-cinza (Sotalia guianensis, van Bénéden, 1864) por comunidades pesqueiras do Rio Grande do Norte, Brasil.

  • Advisor : PRISCILA FABIANA MACEDO LOPES
  • COMMITTEE MEMBERS :
  • PRISCILA FABIANA MACEDO LOPES
  • RENATA GONCALVES FERREIRA
  • SHIRLEY PACHECO DE SOUZA
  • Data: Oct 29, 2012


  • Show Abstract
  • A etnobiologia estuda o Conhecimento Ecológico Local (Local Ecological Knowledge – LEK) e o uso e gestão de recursos naturais por comunidades locais visando compreender como o ambiente é percebido, conhecido e classificado por grupos humanos. Em comunidades de pescadores artesanais, o LEK agrega informações empíricas a respeito da biologia de espécies aquáticas e pode complementar os achados científicos, especialmente em situações de difícil obtenção de dados, como em estudos sobre os aspectos comportamentais – essencialmente submersos – de cetáceos. Os cetáceos, representados pelas baleias e golfinhos, constantemente são alvo de atividades antrópicas, destacando-se a captura acidental de espécies costeiras de pequeno porte, a exemplo do boto cinza (Sotalia guianensis), objeto deste trabalho. Estudos etnobiológicos em comunidades pesqueiras são de grande importância e possibilitam esclarecer aspectos da biologia e conservação desta espécie. Embora bastante estudado ao longo de sua distribuição, ainda existem diversas lacunas no conhecimento sobre S. guianensis. Nesse sentido, o LEK de pescadores artesanais, torna-se uma ferramenta adicional, podendo confirmar e até acrescentar informações sobre a espécie. Este trabalho avaliou o LEK de pescadores artesanais, expostos diuturnamente a populações residentes de S. guianensis, por meio de 116 entrevistas semi-estruturadas. Os pescadores foram indagados a respeito da biologia e classificação do S. guianensis, além de possíveis interações com a espécie. As comunidades estudadas foram Tibau do Sul (n=39), Pipa (n=36) e Baía Formosa (n=41), todas localizadas no litoral sul do Estado do Rio Grande do Norte, Brasil. Pressupôs-se que haveria diferenças entre as comunidades em relação ao LEK dos pescadores, devido tanto à diversidade dos ambientes pesqueiros (lagunar e marinho), quanto ao grau de interferência do turismo. Constatou-se que o conhecimento dos pescadores é relevante e difere conforme a comunidade estudada. Os pescadores entrevistados informaram corretamente características gerais do S. guianensis como aspectos morfológicos, habitat, distribuição, sazonalidade e aspectos comportamentais. Observou-se que houve interferência do turismo sobretudo na designação popular da espécie. Os resultados também sugerem que pescadores de ambiente marinho possuem maior conhecimento sobre a espécie. Evidenciou-se que populações locais acumulam conhecimento de acordo com o ambiente que utilizam, o que torna importante levar em consideração o conhecimento local e a participação popular nos sistemas de manejo de forma a manter o compartilhamento de informações.

2011
Dissertations
1
  • CAROLINA ANGELICA ARAUJO DE AZEVEDO
  • Avaliação da atividade turística sobre a composição e a distribuição das macroalgas marinhas nos recifes de Pirangi (Rio Grande do Norte, Brasil)

  • Advisor : ELIANE MARINHO SORIANO
  • COMMITTEE MEMBERS :
  • ELIANE MARINHO SORIANO
  • MARCOS ROGERIO CAMARA
  • MARIA DAS DORES MELO
  • Data: Feb 25, 2011


  • Show Abstract
  • A área recifal da praia de Pirangi tem sofrido ações antrópicas, principalmente aquelas relacionadas à exploração turística. Para avaliar esses efeitos, amostragens de macroalgas foram realizadas em nove estações, distribuídas em áreas distintas (presença e ausência de turistas), ao longo da franja recifal. A comunidade macrobentônica (algas/corais) foi identificada com uso do método do fotoquadrado, ao longo de transectos de 50 metros, distribuídos aleatoriamente e paralelos à linha de costa. As seguintes categorias gerais foram examinadas em cada transecto: rocha, areia, algas, corais e moluscos. Os dados obtidos no campo foram analisados através do software Coral Point Count with Excel extensions. Um total de 30 espécies de macroalgas e 5 espécies de corais e uma de molusco foi identificado. Nos locais onde a atividade turística era mais intensa, foi observada uma dominância de algas de pequeno porte, enquanto que nos locais sem interferência humana ocorria a predominância de algas foliosas. As macroalgas com maior cobertura percentual foram Sargassum vulgare (59%), Caulerpa racemosa (47%) e Dictyopteris delicatula (33%), em diferentes estações de coleta. A análise de agrupamento dos organismos bentônicos indicadores revelou um padrão na distribuição espacial com cinco faixas: (1) área totalmente submersa caracterizada por apresentar uma flora bastante diversificada; (2) área com predomínio de Caulerpa racemosa e presença de coral de fogo (Millepora alcicornis), (3) área com elevada cobertura de Sargassum vulgare, (4) área de pisoteio caracterizada por espaços vazios, algas de pequeno porte e Zoanthus sociatus e (5) área caracterizada pela presença marcante do coral Palythoa caribaeroum. De acordo com os dados obtidos, nós pudemos inferir que a área estudada vem sofrendo alterações resultantes da atividade turística e que as diferenças observadas na comunidade algal podem ser um indicador importante da saúde da área recifal de Pirangi.

2
  • PAULO AUGUSTO DE LIMA FILHO
  • DIVERSIFICAÇÃO EVOLUTIVA DE GOBIDEOS NO LITORAL BRASILEIRO: PADRÕES CITOGENÉTICOS E ECOMORFOLÓGICOS

     

  • Advisor : WAGNER FRANCO MOLINA
  • COMMITTEE MEMBERS :
  • WAGNER FRANCO MOLINA
  • ALEXANDRE VASCONCELLOS
  • MARCOS ANTONIO NOBREGA DE SOUSA
  • Data: Feb 28, 2011


  • Show Abstract
  • Os peixes da ordem Perciformes caracterizam-se como um modelo importante para o entendimento da estrutura genética de populações marinhas, pois apresentam tanto exemplos de conservação cromossômica como de diversificação cariotípica para alguns grupos. Gobiidae é a família mais especiosa no ambiente marinho. Entre seus representantes, muitas espécies fazem parte de uma fauna críptica pouco percebida e estudada, apresentando ampla distribuição com características comportamentais e reprodutivas que as tornam propícias à ação de barreiras biogeográficas. Morfologicamente esta família apresenta estruturas corporais reduzidas através de simplificações e regressões. Dados citogenéticos, apesar da importância em inferências evolutivas, são incipientes frente sua diversidade de espécies, sobretudo para espécies do Atlântico Ocidental. Visando estimar a diversidade evolutiva em Gobiidae foram desenvolvidas análises citogenéticas e dos padrões corporais, através de morfometria geométrica, em cinco espécies presentes no litoral brasileiro, Coryphopterus glaucofraenum, Bathygobius mystacium, B. soporator, Ctenogobius smaragdus e C. Boleosoma. Os dados obtidos demonstram marcante diversidade cariotípica e morfológica entre as espécies. As inversões pericêntricas e fusões desempenham papel importante na evolução cromossômica desta família, ocasionando diferenças cariotípicas estruturais e numéricas em todas as espécies. Comparações cariotípicas e morfológicas entre amostras geográficas de B. soporator provenientes do litoral do Maranhão, Rio Grande do Norte e Bahia evidenciaram padrões citogenéticos comuns, mas padrões morfológicos diferentes. Uma amostra proveniente do Atol das Rocas revelou conspícua diferenciação cariotípica e morfológica das demais populações continentais, indicando a presença de uma nova espécie insular. As abordagens empregadas revelam diversificações compatíveis com um grupo com características de baixa vagilidade e amplamente sujeito a seleção ambiental decorrente de exigências ecológicas peculiares.

     

3
  • CARLOS EDUARDO ROCHA DUARTE ALENCAR
  • Dinâmica populacional do caranguejo-uçá, Ucides cordatus (Linnaeus, 1763) no município de Porto do Mangue, litoral norte do estado do Rio Grande do Norte.

  • Advisor : FULVIO AURELIO DE MORAIS FREIRE
  • COMMITTEE MEMBERS :
  • Adilson Fransozo
  • FULVIO AURELIO DE MORAIS FREIRE
  • GABRIEL CORREA COSTA
  • Data: Feb 28, 2011


  • Show Abstract
  • O caranguejo-uçá, representa o principal componente da macrofauna dos manguezais, principalmente nas regiões norte e nordeste, sendo um dos principais recursos pesqueiros no Brasil. Embora seja uma espécie de grande importância ecológica e econômica, poucos são os artigos que tratam de aspectos biológicos da espécie, principalmente no estado do Rio Grande do Norte. O objetivo deste trabalho foi estudar a dinâmica populacional do caranguejo-uçá no estuário do Rio das Conchas, pertencente ao município de Porto do Mangue-RN. Durante o período de novembro de 2009 a outubro de 2010 foram realizadas coletas mensais de exemplares da espécie, sempre sobre os mesmos períodos lunares estabelecidos previamente. No total, foram coletados 476 caranguejos, sendo 338 machos e 138 fêmeas. Os machos foram maiores, mais pesados e em maior proporção que as fêmeas. O período reprodutivo para a espécie foi limitado entre os meses de novembro a maio, sugerindo uma mudança na legislação ambiental atual. Os valores de maturidade sexual mostram que a espécie está sobrexplorada e as capturas que ocorrem na região estão fora do padrão de tamanho mínimo de captura estimado segundo a legislação (LC=6,0cm). O período de ocorrência de mudas ocorreu na estação seca com pico em outubro. A análise de crescimento baseado nos parâmetros de Von Bertalanffy foi calculada utilizando o ajuste não-linear usando-se modas (AJMOD). Evidenciaram-se altas taxas de crescimento tanto para machos (L∞=7,54cm; k=0,95; t0=-0.08; tmáx=4,84) como para fêmeas (L∞=6,50; k=1,2; t0=-0.008; tmáx=3,28), contrastando com dados obtidos na literatura utilizando outras técnicas. O período de recrutamento para a espécie é sazonal com dois picos de ocorrência, um no período chuvoso e outro no período seco. Este trabalho representou o primeiro esforço sobre o entendimento da ecologia do caranguejo-uçá para o litoral norte do Estado do Rio Grande do Norte.

4
  • CAROLINE GABRIELA BEZERRA DE MOURA
  • Matéria Orgânica Dissolvida Alóctone x Autóctone: Influências para o balanço de carbono em experimentos de mesocosmo

  • Advisor : ANDRE MEGALI AMADO
  • COMMITTEE MEMBERS :
  • ADRIANO CALIMAN FERREIRA DA SILVA
  • ANDRE MEGALI AMADO
  • FABIO ROLAND
  • VINICIUS FARJALLA
  • Data: Feb 28, 2011


  • Show Abstract
  • O aumento da concentração de CO2 na atmosfera tem sido observado, principalmente a partir da revolução industrial. Uma das causas principais desse comportamento tem sido a queima de combustíveis fósseis. Isso tem levado a alterações globais no ciclo do carbono. Desta forma é de suma importância trabalhos que mostrem a influência dos sistemas em geral e suas contribuições relativas na dinâmica e ciclo do carbono. Dentro deste contexto, os ecossistemas aquáticos apresentam importância no processamento da matéria orgânica produzida internamente nos sistemas aquáticos (autóctone), bem como a matéria orgânica trazida dos sistemas terrestres (alóctone). Os principais organismos que metabolizam a matéria orgânica dissolvida (carbono orgânico dissolvido – COD) presente nos sistemas aquáticos são as bactérias. No entanto a qualidade da matéria orgânica determina a preferência e a via metabólica (produção bacteriana - PB ou respiração bacteriana - RB) pela qual o carbono será direcionado quando assimilado pelas bactérias. Nos sistemas aquáticos a diversidade da matéria orgânica presente, muitas vezes estimula a produção bacteriana. Desta forma, os objetivos deste trabalho foram avaliar os efeitos do COD alóctone e autóctone na PB e RB, além de avaliar o efeito da mistura de COD sobre o balanço de CO2 em experimento de mesocosmo. Para testar os objetivos realizamos um experimento de mesocosmo com o arranjo experimental do tipo (2x2) destinado a simular condições onde houvesse o predomínio de matéria orgânica autóctone (fitoplâncton), alóctone (detrito de vegetação terrestre) e ambas combinadas. Consistindo em quatro tratamentos incluindo o Controle. A duração do experimento foi de 42 dias.  Verificamos no geral que os tratamentos enriquecidos com matéria orgânica alóctone apresentaram as maiores taxas metabólicas (RB, CO2), o que provavelmente esteve relacionado à qualidade da matéria orgânica utilizada. Observamos também que o sistema ao longo das 6 semanas tendeu a se comportar de predominantemente heterotrófico (nos primeiros dias) para autotrófico (nos últimos dias).


5
  • DENISE DE FREITAS TORRES
  • Uso da biodiversidade entre populações humanas na Caatinga e na Mata Atlântica, Rio Grande do Norte, Nordeste do Brasil.

  • Advisor : ALEXANDRE VASCONCELLOS
  • COMMITTEE MEMBERS :
  • ALEXANDRE VASCONCELLOS
  • BRUNO CAVALCANTE BELLINI
  • PRISCILA FABIANA MACEDO LOPES
  • REINALDO FARIAS PAIVA DE LUCENA
  • Data: Jun 14, 2011


  • Show Abstract
  • As interações estabelecidas entre as pessoas e os recursos naturais podem ser influenciadas por fatores que vão desde a disponibilidade ambiental até o interesse pessoal por um recurso específico. Este estudo comparou o uso de animais e plantas entre duas comunidades humanas inseridas em ambientes distintos (Caatinga e Mata Atlântica), objetivando identificar as diferenças, as similaridades e os principais fatores que influenciam o conhecimento sobre as espécies úteis em cada comunidade. Para tanto foram utilizados questionários semiestruturados que abordavam sobre as espécies de animais e plantas úteis e sobre o perfil socioeconômico dos entrevistados. Quarenta pessoas foram entrevistadas na comunidade Caraúbas (Mata Atlântica) e trinta na comunidade Barrocas (Caatinga), localizadas no Estado do Rio Grande do Norte. Foram citadas 193 espécies animais e 204 espécies de plantas. As comunidades apresentaram uma baixa similaridade de animais (17%) e plantas (23%) úteis. Além disso, foram observadas diferenças significativas quanto à riqueza e a diversidade de espécies conhecidas entre as comunidades e de acordo com fatores como gênero e idade dos entrevistados dentro das comunidades. Os resultados mostraram ainda que o conhecimento sobre as espécies animais utilizadas na alimentação nas duas comunidades foi influenciado pela idade dos entrevistados e que pessoas com baixa renda familiar na comunidade Caraúbas possuíam um conhecimento maior sobre as espécies de plantas úteis do que pessoas com maior renda. Os resultados mostraram que as diferenças ambientais locais são fundamentais na seleção das espécies, mas mostrou também que dentro das comunidades existem outros fatores como gênero, idade e renda que também tendem a influenciar o conhecimento sobre as espécies. É importante considerar fatores culturais, econômicos, sociais e ambientais para melhor entender as relações existentes entre as pessoas e os recursos naturais, de forma que estas informações possam ser utilizadas para favorecer a implementação de medidas conservacionistas.

6
  • EDUARDO SILVA DE OLIVEIRA
  • Uso e conservação da fauna por populações humanas no Rio Grande do Norte, Nordeste do Brasil.

  • Advisor : ALEXANDRE VASCONCELLOS
  • COMMITTEE MEMBERS :
  • ALEXANDRE VASCONCELLOS
  • GINDOMAR GOMES SANTANA
  • HELDER FARIAS PEREIRA DE ARAUJO
  • PRISCILA FABIANA MACEDO LOPES
  • Data: Jun 15, 2011


  • Show Abstract
  • Muitos países subdesenvolvidos são caracterizados por uma significativa diversidade sociocultural e por uma acentuada pobreza em grande parte da população, que fazem uso da caça de animais como uma fonte alternativa de alimento e para outros fins. O estudo objetivou investigar se a distância das populações humanas da zona rural em relação à zona urbana e fatores socioeconômicos podem ser preditores de um maior conhecimento sobre as espécies da fauna utilizadas. Além disso, o estudo objetivou também testar uma ferramenta capaz de gerar uma lista da fauna prioritária para a conservação local a partir do conhecimento local. Os dados foram coletados por meio de 30 entrevistas utilizando formulários semi-estruturados em quatro comunidades rurais no município de Pedro Avelino, RN. Foram calculados o fator de consenso dos informantes (ICF), a importância relativa (IR) e o nível de fidelidade (FL). Adicionalmente, foi calculado o índice de Shannon-Wiener para as categorias de uso: estimação, alimentar, medicinal e para a multiplicidade de uso por informante. Os entrevistados reconhecem 83 espécies pertencentes a 45 famílias de animais. As espécies citadas pertencem a seis grandes grupos taxonômicos: aves, mamíferos, répteis, anfíbios, peixes e insetos. O conhecimento sobre a utilização de animais para as categorias de uso definidas neste trabalho não mostrou relação significativa com os fatores socioeconômicos e nem com a distância das comunidades da zona rural para a zona urbana de Pedro Avelino. Os resultados sugerem, portanto, que a pobreza nivela o conhecimento sobre o uso da fauna independente da distância que as comunidades encontram-se da zona urbana. As listas geradas permitirão direcionar estudos ecológicos mais aprofundados visando à conservação das espécies do bioma Caatinga. Desta forma, é importante considerar as interações existentes entre as pessoas e os animais para melhor entender a dinâmica de utilização e fornecer, assim, subsídios para a conservação das espécies.

     

7
  • VITOR HUGO FERNANDES DE VASCONCELOS
  • Emissões naturais e antrópicas de nitrogênio e fósforo para os principais açudes da bacia hidrográfica do Rio Seridó, RN

  • Advisor : JOSE LUIZ DE ATTAYDE
  • COMMITTEE MEMBERS :
  • JOSE LUIZ DE ATTAYDE
  • EDUARDO MARTINS VENTICINQUE
  • LUIZ DRUDE DE LACERDA
  • Data: Jun 21, 2011


  • Show Abstract
  • Emissões naturais e antrópicas de nitrogênio e fósforo para os principais açudes da bacia hidrográfica do Rio Seridó, RN

8
  • LAYSE ARANHA MARINHO
  • Contribuição à citogenética de testudines e análise de assimetria flutuante em Eretmochelys imbricata, Cheloniidae.

  • Advisor : WAGNER FRANCO MOLINA
  • COMMITTEE MEMBERS :
  • CARLOS ALFREDO GALINDO BLAHA
  • FULVIO AURELIO DE MORAIS FREIRE
  • MARCELO RICARDO VICARI
  • Data: Jul 8, 2011


  • Show Abstract
  • O presente trabalho procurou contribuir ao conhecimento da ordem Testudines sob o ponto de vista citogenético e morfológico. A respeito dos aspectos citogenéticos foi realizada a caracterização da espécie Mesoclemmys tuberculata (n=5), endêmica da caatinga, através de técnicas de citogenética convencional e molecular. Esta espécie apresentou 2n=58, NF=64, primeiro par submetacêntrico, o segundo metacêntrico e o terceiro subtelocêntrico, sendo os demais micromossomos telocêntricos. Esta espécie apresentou um par portador nucleolar, coincidente com DNAr ribossomal 18S e que se mostrou heterocromático. Pequenos blocos heterocromáticos também foram encontrados em regiões centroméricas dos maiores cromossomos, assim como em regiões terminais na maioria dos outros cromossomos do complemento, que se mostraram GC+. Seqüências teloméricas mostraram padrões variáveis de intensidade de sinal, sendo que alguns repeats foram mais intensos nos microcromossomos e de forma sutil nos maiores. Os padrões de bandamento G quando comparadas com outras espécies do gênero mostraram uma pronunciada similaridade entre ambas. Sob o ponto de vista morfológico, realizou-se estudos de assimetria flutuante em Eretmochelys imbricata, tartaruga marinha, através de métodos de aferição comparativa entre filhotes e adultos e as suas implicações na seleção natural. A partir dos valores de assimetria encontrados foi calculado o valor de herdabilidade estricto para essas características, com o calculo baseado em apenas um parental. As fêmeas adultas não apresentaram assimetria flutuante bilateral (AF=0) quanto ao número de placas do casco e plastrão, enquanto os filhotes, vivos e mortos, apresentaram variação. Na análise entre fêmeas X filhotes encontrou-se diferença significativa para as características de número de .placas do casco (p=0,006) e largura da nadadeira posterior (p=0,001) entre estes grupos. Os níveis de AF sugerem um indicador eficiente quanto à viabilidade ou manutenção do indivíduo até a fase reprodutiva. Ao analisarmos o coeficiente de herdabilidade (h2) da AF observou-se que ambas apresentam valores baixos, e não significativo estatisticamente (p>0,1)

     

9
  • LUIZ VICENTE BURLE MACIEL
  • Análise dos remanescentes de floresta Atlântica no estado do Rio Grande do Norte: Uma perspectiva em alta resolução.

  • Advisor : MARCIO ZIKAN CARDOSO
  • COMMITTEE MEMBERS :
  • ADRIANA MONTEIRO DE ALMEIDA
  • EDUARDO MARTINS VENTICINQUE
  • JEAN PAUL METZEGER
  • MARCIO ZIKAN CARDOSO
  • Data: Jul 8, 2011


  • Show Abstract
  • A perda e fragmentação de habitat são consideradas as principais ameaças a biodiversidade. Essas ameaças atuam ao nível da paisagem, o que impele a necessidade de manejar paisagens por inteiro e não somente suas componentes. Embora o acompanhamento sistemático do bioma Mata Atlântica venha sendo feito desde o final da década de oitenta,  dados atualizados sobre fragmentação florestal para a sub-região de Pernambuco são praticamente inexistentes. O presente estudo teve como objetivo mapear, sobre imagens de alta resolução espacial, os remanescentes do bioma Mata Atlântica no estado do Rio Grande do Norte e conduzir uma análise ao nível de paisagem. Os resultados mostram que a paisagem encontra-se altamente fragmentada, onde restam cerca 8% dos remanescentes florestais do bioma. A grande maioria dos fragmentos (72%) são menores do que 10ha, e somente 3% dos fragmentos possuem área maior do que 100ha. Embora seja elevado o grau de fragmentação, a distância média entre fragmentos encontrada foi pequena (74,62 m), essa estimativa  é menor do que a que tem sido observada para o bioma (1440m). Há indícios de que mudanças bruscas na quantificação da estrutura da paisagem podem ocorrer quando se observa a fragmentação em alta resolução espacial. Os resultados aqui apresentados podem ser utilizados em ações de manejo, com vistas a tornar o cenário mais propício a manutenção da biodiversidade.

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