Reptile Species Richness and Distribution: What Can We Learn from Arid and Semiarid Environments? (pp. 75-94)
Authors: (Aurelio Ramirez-Bautista, Raciel Cruz-Elizalde and Uriel Hernandez-Salinas, Universidad Autonoma del Estado de Hidalgo, Mexico)
Abstract: Arid and semiarid environments of the world hold a remarkable richness of reptile species. Knowledge on richness, diversity and distribution is important for determining biogeographic and ecological processes that elucidate the structure of communities. At a local scale, ecological factors determine processes that influence species richness and its composition, and at a regional level, events such as extinction and speciation are considered the most important factors. In this chapter, we evaluated species richness and the taxonomic diversity of the reptile communities from arid and semiarid environments in the state of Hidalgo, México; and we also analyzed reptile communities of the central and northern regions of the country. The state of Hidalgo has six arid and semiarid environments; xeric scrub (XS), held the highest species richness with 42 species, followed by pine forest (PF), with 25 species, oak forest (OF) with 19 species, farmland (F) and secondary vegetation (SV) with 14 species each, and riparian vegetation (RV) with 13 species. With respect to the analysis of the taxonomic diversity, the SV and RV had the highest values, the XS and F values close to the average expected by a calculated null model, and PF and OF had the lowest values. When comparing Hidalgo region with regions from northern México, such as Sonora (SON), the latter had the highest species richness, followed by Tamaulipas (TAM), Hidalgo (HGO), and Guadalcázar (GDZ) with lowest number of species. The highest taxonomic diversity was found in TAM, followed by SON, and lowest value was reported in HGO and GDZ. The richness and diversity of reptiles from Hidalgo is characteristic of the regional pool of species from central Mexico, and is dissimilar from that reported in the northern section of the country. This suggests distinct conformation of the communities of reptiles which is likely due to environmental heterogeneity and different processes that regulate the establishment of the biological communities.