Banca de DEFESA: Wagner de França Alves

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : Wagner de França Alves
DATE: 22/06/2023
TIME: 09:00
LOCAL: Google Meet
TITLE:

SPATIAL PATTERNS OF BIODIVERSITY AND STABILITY ALONG URBANIZATION AND LAND USE GRADIENTS

KEY WORDS:

Metacommunities, β-diversity, replacement, nestedness, asynchronous dynamics, biotic homogenization.

PAGES: 132
BIG AREA: Ciências Biológicas
AREA: Ecologia
SUMMARY:

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.

COMMITTEE MEMBERS:
Interno - 1714892 - ADRIANO CALIMAN FERREIRA DA SILVA
Presidente - 3060333 - ANDROS TAROUCO GIANUCA
Externo à Instituição - DUARTE DE SERPA PIMENTEL TEIXEIRA
Interna - 1677189 - GISLENE MARIA DA SILVA GANADE
Externo à Instituição - VINÍCIUS AUGUSTO GALVÃO BASTAZINI - UE