The role of spatial heterogeneity in diversity of squamate reptiles in the Atlantic Forest highlands of southeastern Brazil.

Spatial heterogeneity of vegetation is considered to be one of the most important factors that can influence species richness in a region and, therefore, an important driver for species diversity. Here, we investigate how squamate diversity varies throughout a heterogeneous area in southeastern Atlantic Forest. Our sampling site corresponded to a mosaic of forest and open fields in Curucutu nucleus, Serra do Mar State Park, São Paulo State, Southeastern Brazil. Species diversity varied throughout the mosaic in terms of species composition and relative abundance, with some species being clearly associated with a particular physiognomy. However, a decrease is observed in species richness in forest, after the rarefaction method is applied, showing that when the abundance effect is excluded, only species composition differed between physiognomies. On the other hand, both space and environmental heterogeneity were associated with diversity and distribution of squamates. Our results emphasize the importance of environmental heterogeneity, as well as the influence of the spatial location of the sample units, in structuring squamate diversity in a highland assemblage from the Atlantic Forest.