Taxonomic and functional diversity of the amphibian and reptile communities of the state of Durango, Mexico

Taxonomic and functional diversity metrics have been used together to describe functional patterns through species richness in a given area or region. Many scientists have shown that these two metrics can be positively correlated; nevertheless, other studies have found the opposite. In either case, the usefulness of both metrics has helped to develop more reasoned conservation strategies in areas where biodiversity loss is occurring at an accelerated rate. In this study, we calculated metrics of both taxonomic and functional diversity in amphibian and reptile communities located in a variety of vegetation types (xeric scrub, pine forest, pine-oak forest, cloud forest, oak forest, and tropical dry forest) in the state of Durango. Using species richness (157 species: 36 amphibians and 121 reptiles) for the state of Durango, we found that the amphibian communities present in pine forest and pine-oak forest showed high values of taxonomic diversity (high Delta + values), meaning that the communities in these vegetation types are composed of a complex network of families and genera. The same result was true of reptiles present in oak forest, tropical dry forest, and xeric scrub. The communities formed by the snakes showed high values of functional richness, functional evenness, and functional dispersion in all vegetation types, as did the lizard communities present in xeric scrub. This indicates that the ecological functions of lizards and snakes (i.e., predators; pest controllers; links in the trophic chain) are an integral element of the functioning of these ecosystems. These results showed that vegetation types with greater taxonomic and functional diversity in amphibians and reptiles are sites that promote the sustainability of an ecosystem in particular ways, making them more suitable for conservation of these vertebrates. The information from this study can be useful in developing protection programs and implementing conservation strategies for several biological groups in particular areas of Durango and the Sierra Madre Occidental, helping to ensure the permanence of the remarkable biota of northern Mexico.