Taxonomic, functional, and phylogenetic diversity of lizard assemblages across habitats and seasons in a Brazilian Cerrado area

One of the core issues in community ecology is the understanding of mechanisms that determine community structure. In this study, we examine how two structurally distinct habitats (campo sujo - a grassy savanna habitat with low shrubby cover - and seasonal semi-deciduous forest) and distinct hydrological seasons (dry and rainy) influence the taxonomic, functional and phylogenetic diversity of lizard assemblages in a savanna area in the Brazilian Cerrado. We used pitfall traps to sample lizards from May 2000 to February 2002. To quantify spatio-temporal changes in the lizard assemblages, we used parameters of taxonomic (species richness - SR), functional (functional diversity - SES.FD, functional redundancy - FR and functional dispersion - FDis), and phylogenetic diversity (phylogenetic species richness - PSR and phylogenetic species variability - PSV). We also estimate functional and phylogenetic structure of the assemblages in each habitat during dry and rainy seasons. We recorded 182 lizards distributed among 14 species. Species composition differed among habitat types, but did not differ seasonally within habitats. SES.FD, FDis, and FR also differed among habitat types but not among seasons, with SES.FD and FDis being greater in seasonal semi-deciduous forest, while FR was greater in campo sujo. SR, PSR, and PSV were not influenced by the factors analysed. The lizard assemblage of campo sujo was functionally clustered in the dry season and phylogenetically clustered in the rainy season. These results demonstrate that differences among habitat types and seasons are important in shaping the taxonomic, functional, phylogenetic diversity and structure of lizard assemblages in the savanna area studied. Our study also demonstrates the importance of using different measures of diversity to obtain a better understanding on the mechanisms that influence the lizard assemblages in a highly seasonal environment.