Phylogenetic structure and diversity among herpetofaunal communities along a successional gradient of a tropical dry forest in Mexico

Abstract

The tropical dry forest (TDF) is one of the most biodiverse ecosystems on earth, but also one of the most threatened. Therefore, it is critical to understand the processes that control community assembly and generate diversity during succession. We surveyed 15 herpetofaunal communities from a chronosequence of succession plots and tested whether phylogenetic structure (nonrandom distribution of species with respect to phylogeny) and phylogenetic diversity (incorporation of phylogenetic differences between species to measure biodiversity) differed among seasons and succession stages of the TDF in western Mexico. Phylogenetic structure and diversity of both groups showed temporal shifts. Our data suggest a role of environmental filtering in the first succession stages: during the rainy season in amphibians, allowing the coexistence of closely related species in water ponds, while for reptiles during the dry season, where higher exposure to solar radiation and humidity loss predominate in pastures. The more distantly related species in primary and secondary forests in later succession stages may predict ecosystem stability assuring the sufficient ecological strategies in a community to achieve the persistence of the ecosystem under changing conditions. Our results strengthen the arguments for promoting the conservation and managing of secondary forests under recovery to maintain phylogenetic diversity.