Environment, space or connectivity: Which are the driving forces on aquatic insect assemblages in impounded streams?

Abstract

We tested if linear spatial distance between two sites, environmental variables or river distance, are important drivers of aquatic insect assemblages composition in impounded rivers, located at the transition between Cerrado/Amazonia. Regarding the scale of the study, we believe that flying adults have no dispersal limitation. Hence, our hypothesis is that species composition is structured mainly by environmental variables. We tested our hypothesis with partial Mantel. The model, which included environmental variables was the one that better explained the species composition in impounded rivers. We believe that the strong relationship between assemblages and environment is due to aspects related to acquisition of shelter and food resources. © 2016, Sociedad Venezolana de Entomología.