Local environmental variables are the best beta diversity predictors for fish communities from the Brazilian Cerrado streams

Environmental characteristics, spatial structures, and landscape features are ecological factors that drive beta diversity in stream communities, but the effects of these factors, considering multiple spatial scales on beta diversity in aquatic communities, still remain a goal of community ecology. Using the distance-based redundancy analysis (db-RDA) and variance partitioning, we evaluated the contribution of the local environment, regional, and spatial variables to total beta diversity and its components (i.e., species replacement and richness difference) for fish communities in 59 streams from the Brazilian Cerrado. The influence of local environmental, regional, and spatial variables on beta diversity was distinct along different spatial scales. Specifically, local environmental variables were the main drivers of dissimilarity between streams. We suggest that the environmental filter is the primary structuring mechanism of local communities in stream fishes in the Cerrado, regardless of the spatial scale. Together, spatial and regional variables may be considered complementary mechanisms to explain the variation in the beta diversity pattern. Thus, based on high beta diversity values and the number of unique species, our findings suggest that the preservation of stream structural features is necessary to maintain regional diversity.