Effects of habitat modification and environmental variables on the diversity of amphibians in western Mexico, along a gradient of environmental disturbance

Abstract

The diversity of amphibians that occur in tropical dry forest of western Mexico was evaluated. The study was carried out within an anthropogenic disturbance gradient in which the structure and composition of the habitat in each of the sites analysed was characterised to determine the environmental and structural variables that influence the presence or absence of amphibians in the landscape matrix. Amphibians were recorded in three conserved sites, three rural, and three urban sites from 2015 to 2018. Each site was digitised using Google Earth and ArcGis geographic information systems. Nine sampling sites (buffers), each one km in diameter, were characterised, and within each site, these vertebrates were sampled monthly during the dry season and rainy season to determine the diversity and structure of the amphibian communities. For the entire landscape gradient, 18 species belonging to seven families were recorded. The greatest diversity of species was recorded in the conserved sites, followed by rural sites, and the least diversity in urban sites. The results showed that diversity is determined to a highest extent by the similarity of species among the more conserved sites and the variation in habitat structure determines the biggest diversity of species. The sites with the greatest similarity among species are conserved sites (tropical dry forest) and rural sites, which form a diverse system of crucial habitats for amphibians in this complex landscape. This implies that the participation of different sectors, such as academic, productive, and social is required for the monitoring and maintenance of the physical properties of patches of natural and rural vegetation that enable the permanence of amphibian communities in tropical ecosystems.