Hydro‑climatic changes promote shifts in zooplankton composition and diversity in wetlands of the Lower Paraná River Delta

GUTIERREZ, MARÍA FLORENCIA; EPELE, LUIS BELTRÁN; MAYORA, GISELA; AQUINO, DIEGO SEBASTIÁN; MORA, CELESTE; QUINTANA, RUBÉN D.; MESA, LETICIA

HYDROBIOLOGIA

SPRINGER

Lugar: Berlin; Año: 2022

0018-8158

The Paraná River Delta is one of the most biodiverse and largest mosaic of wetland ecosystemsin South America. Yet its natural hydrological patterns are being strongly distorted by sustained land use intensifcation and extraordinary severe droughts. Understanding whether the aforementioned processes negatively afect wetland biodiversity is urgently needed to delineate accurate conservation actions. In this study we analyzed zooplankton diversity patterns at the local and regional scales, as well as compared species composition between natural (freshwater marshes) and artifcial water bodies (ditches), all of them afected by livestock activities. Our studyinvolved two hydro-meteorologically contrasting conditions within two consecutive years of sustained drought: a high water stage (HW) and a low water stage (LW). Adverse environmental conditions in the LW period enhanced local zooplankton abundance and taxonomic richness, but decreased beta diversity and individual biomass, leading to a simplifcation of functional diversity. Species composition difered between freshwater marshes and ditches; however, they equally contributed to the zooplankton diversity metrics, suggesting that both kinds of freshwatersacted as complementary contributors to regional zooplankton diversity. Considering the regional drought patterns occurring in this landscape, we expect a generalized biotic and functional homogenization of zooplankton wetland diversity in the very next few years