Effects of Vegetation Density on the Diversity of Lizards in an Area of the Brazilian Cerrado

Abstract

The Cerrado is a highly threatened biome that harbors a great portion of Brazilian biodiversity, including many endemic species. Such richness may reflect its environmental heterogeneity, which includes different vegetation types (from grasslands to forests). Several endemic species in the Cerrado are strongly associated with open vegetation types. Recent studies have shown that woody encroachment can negatively impact several components of biodiversity. In the present study, we provide information on variation in lizard diversity across different vegetation types in a protected area located in the southern portion of the Cerrado and evaluated the effect of vegetation density on lizard taxonomic, functional, and phylogenetic diversity. We predicted that the three aspects of lizard diversity would be negatively affected by vegetation density and that Beta diversity would vary significantly across the vegetation gradient. We confirmed nearly all of our predictions, except for functional diversity, which, contrary to our expectations, was positively influenced by vegetation density. We also found that Beta diversity indices based on both species composition/abundance and phylogenetic features of communities experience a significant turnover across the vegetation density gradient. This study greatly strengthens previous studies that suggest a negative impact of vegetation density (and, consequently, woody encroachment) on lizard diversity. Therefore, managers of protected areas in the Cerrado should consider the use of strategies to avoid woody encroachment, like fire management with prescribed fires.