Banca de DEFESA: RAYANE FERNANDES VANDERLEY

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : RAYANE FERNANDES VANDERLEY
DATA : 25/03/2019
HORA: 09:00
LOCAL: Sala de videoconferência PoP-Centro de convivência
TÍTULO:

Abiotic driving factors of phytoplankton structure community and cyanobacteria dominance in tropical semiarid reservoirs

PALAVRAS-CHAVES:

: community structure; nutrients; light; morpho-functional groups; regulating

PÁGINAS: 35
GRANDE ÁREA: Ciências Biológicas
ÁREA: Ecologia
RESUMO:

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.  

MEMBROS DA BANCA:
Interna - 2412921 - JULIANA DEO DIAS
Presidente - 1345773 - RENATA DE FÁTIMA PANOSSO
Externo à Instituição - ROSEMBERG FERNANDES DE MENEZES - UFPB
Interna - 1764855 - VANESSA BECKER