Limnetica 39
Environmental controls on zooplankton during hydrological periods of flooding and flushing in an Amazonian floodplain lake
The hydrological regime exerts a strong control on environmental and biological variables in floodplains. To better understand this process, the present study evaluates the influence of environmental variables on zooplankton community structure, focusing on the hydrological variation of the flood pulse. For this purpose, we address the following questions: (i) What is the effect of hydrologic period on environmental characteristics and the structure of zooplankton community? (ii) Do environmental and biological similarities between sampling sites in a lacustrine ecosystem differ within flooding and flushing periods? (iii) How do zooplanktonic organisms respond to environmental gradients? To achieve this work, environmental and biological samples were collected in 20 sampling sites along the Lago Grande do Curuai in March (flooding period) and September (flushing period) of 2013. While some zooplankton taxa showed relationship with some environmental variables, we estimate that the hydrological variation had a higher control over the taxonomic composition of Lago Grande do Curuai. Therefore, the strong flow that promotes connectivity between the habitats in the floodplain lake may also justify the similar pattern of heterogeneity between sampling sites for the zooplankton community in both periods, despite their environmental differences.
