Colonization and succession of zooplankton after a drought : influence of hydrology and free-floating plant dynamics in a floodplain lake

FONTANARROSA M.S; CHAPARRO, G.; O'FARRELL INÉS

WETLANDS

SPRINGER

Lugar: Berlin; Año: 2016 vol. 36 p. 85 - 100

0277-5212

We analyzed zooplankton colonization and successionfollowingatemporarydrought inavegetatedlakefroma floodplain wetland of the Lower Paraná River (Argentina). We took samples of zooplankton and phytoplankton at four habitats of the lake characterized by the presence-absence of emergent or free-floating macrophytes along a 18-month period after the drought.Microzooplankton dominated along the study and macrozooplankton showed seasonal increments in cold seasons. Temporal patterns of broad taxonomic zooplankton groups were associated to hydrology-driven factors, like changes in water depth, conductivity and edible phytoplankton and seasonal changes and not related with free floating plants. Nevertheless, spatial and temporal patterns of species composition were closely linked to the dynamics of free-floating plants. A clear shift from pelagic to littoral zooplankton taxa was registered when free-floating plants colonized. This study expands the knowledge on the composition and dynamics of zooplankton from floodplain lakes after the disturbance caused by a severe drought. Our results highlight the influence of water level fluctuations as drivers of zooplankton abundance and the joint effect of seasonal changes and free-floating plant dynamics on zooplankton species composition and richness.