Are the patterns of zooplankton community structure different between lakes and reservoirs? A local and regional assessment across tropical ecosystems

Lakes and reservoirs present contrasting differences regarding origin, age and trophic state that may influence their biological communities. In the face of the inevitably rising number of reservoirs worldwide, our objective was to investigate the differences in zooplankton community structure and diversity patterns from 98 tropical shallow lakes and reservoirs (northeast Brazil). We tested the hypothesis that reservoirs have less diverse communities, which could be associated with ecosystem age or high productivity (a typical local pattern). The results show that most reservoirs are eutrophic ecosystems that hold distinct zooplankton communities in comparison with lakes. Despite their higher productivity, reservoirs played an essential role in subsidizing zooplankton diversity as they had higher gamma diversity because of the number of exclusive species, especially for the Rotifera group. The zooplankton density and biomass were also higher in the reservoirs, but this pattern was not associated with higher species dominance. Lakes also played a central role in zooplankton diversity, having a distinct species composition. Jointly, lakes and reservoirs help to maintain the zooplankton species pool at a regional level, suggesting the importance of complementarity in community composition between artificial and natural aquatic ecosystems on large-scale patterns of zooplankton biodiversity.