Banca de DEFESA: ANA KAROLINA DOS SANTOS SILVA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : ANA KAROLINA DOS SANTOS SILVA
DATE: 27/02/2026
TIME: 08:30
LOCAL: LABORATÓRIO DIDÁTICO I (DECOL/UFRN) e Google Meet (https://meet.google.com/xqd-sfqx-qeq)
TITLE:

Extreme hydrological fluctuations drive resource use efficiency in plankton in a tropical reservoir

 

KEY WORDS:

TROPHIC INTERACTIONS; TIME SERIES; SEMI-ARID REGION; EXTREME DROUGHT; FUNCTIONAL GROUPS

 

PAGES: 43
BIG AREA: Ciências Biológicas
AREA: Ecologia
SUMMARY:

Seasonal hydrological fluctuations influence the volume of water in lakes and reservoirs and, consequently, the dynamics of limnological variables, affecting the structure and functioning of planktonic communities. This study analyzed a long series of data (15 years) from a reservoir in the tropical semi-arid region, with the aim of evaluating the effects of hydrological fluctuations on resource use efficiency (RUE) as well as on the structure of planktonic communities over time. The results indicated that hydrological periods played a strong structuring role on the functional groups of zooplankton and phytoplankton, with marked differences, especially between periods of flooding and extreme drought. In the zooplankton community, extreme drought was characterized by a significant increase in the biomass of raptorial copepods, which actively seek food. In contrast, in phytoplankton, it was associated with the dominance of potentially mixotrophic groups, while flooding was marked by a greater contribution from autotrophic species, without flagella and of various forms. The zooplankton RUE showed a positive trend over time, in addition to occasional increases, driven by the increase in biomass of functional groups of zooplankton. The RUE of phytoplankton differed significantly between periods: nutrient use efficiency (RUE Phyto:TP, Phyto:Nitrate) was lower in extreme drought compared to flooding, while light use efficiency (Phyto:Secchi; Phyto:Zeu) was higher. The RUE of zooplankton was significantly associated only with phytoplankton light efficiency metrics, reinforcing that light availability, rather than nutrients, is an important factor in structuring the phytoplankton community and mediating trophic interactions in semi-arid regions. These results highlight the ecological flexibility of plankton and provide important information on trophic dynamics in ecosystems strongly influenced by hydrological fluctuations due to extreme events related to drought or rain.

 

COMMITTEE MEMBERS:
Presidente - 2412921 - JULIANA DEO DIAS
Externa à Instituição - CLAUDIA COSTA BONECKER
Externo à Instituição - ROSEMBERG FERNANDES DE MENEZES - UFPB