Patterns of endemism and beta diversity in amphibians and reptiles of the Amazon Basin: effects of habitat heterogeneity and anthropic impact

López-Rojas J.J.; Solé M.; Lourenço-De-Moraes R. · Biological Journal of the Linnean Society (2025) · DOI: 10.1093/biolinnean/blaf023

Resumen

Identifying conservation priorities in ecological hotspots such as the Amazon Basin requires an understanding of beta diversity and endemism patterns. This study explores amphibian and reptile diversity across 32 Amazonian ecoregions, analysing their relationships with habitat heterogeneity and anthropogenic impacts. Using spatial data for 1839 species, we calculated weighted endemism and beta diversity and its components (turnover and nestedness). Habitat heterogeneity variables (water, bare ground, trees, flooded vegetation, and rangeland) and anthropogenic impact indicators (built areas and crops) were derived from land cover data, and regression models assessed their effects on diversity metrics. Our results reveal substantial variability in endemism across ecoregions, with the western montane ecoregions exhibiting the highest values. Beta diversity, driven primarily by turnover, was elevated in Anura, Gymnophiona, lizards, and snakes, reflecting regionally distinct species compositions. Habitat heterogeneity, particularly bare ground, positively influenced both endemism and beta diversity, while caudates and crocodilians showed lower sensitivity to habitat variability. Anthropogenic impacts such as built areas contributed to higher values of endemism and beta diversity across most groups, whereas crops had minimal effects. These findings highlight the Amazon Basin's western montane ecoregions as critical biodiversity hotspots with high endemism and species turnover. The dominance of turnover over nestedness emphasizes the unique species compositions within each ecoregion. Targeted conservation strategies are urgently needed to mitigate the impacts of urbanization and prioritize the preservation of habitats with high endemism, ensuring the long-term protection of Amazonian biodiversity.

Instituciones: Universidad Nacional de San Martín