Turnover Drives High Benthic Macroinvertebrates' Beta Diversity in a Tropical Karstic Lake District

Beta diversity is useful to explain community assembly across landscapes with spatial variation. Its turnover and nestedness components help explain how beta diversity is structured across environmental and spatial gradients. Assessing beta diversity in freshwater ecosystems is essential to conservation, as it reveals the mechanisms that maintain regional diversity. Nonetheless, so far, no studies have examined the beta diversity patterns of benthic macroinvertebrates in tropical lakes. We aimed to examine the beta diversity patterns and components of the deep benthic macroinvertebrate communities of tropical Lakes of Montebello, Mexico, along spatial and environmental gradients. We used presence/absence data of deep benthic macroinvertebrates from 13 lakes distributed along environmental and spatial gradients. We calculated beta diversity indices and correlated them to each lake's environmental and spatial variables. The macroinvertebrate communities of the Lakes of Montebello showed high beta diversity driven by a turnover pattern that emphasises the importance of regional-scale conservation efforts. Short distances between lakes and high environmental heterogeneity promoted species turnover, resulting in a great singularity level among lakes. We did not find significant correlations between the beta diversity components and the environmental variables, suggesting a random distribution given by the species' high dispersal capacity in a reduced spatial extent across the lake district.