Global Diversity Patterns in Anurans Are Determined by Terrestrial and Arboreal Species.

Abstract

Understanding the mechanisms shaping biodiversity distribution patterns is essential in ecology, and species distributions are closely influenced by environmental factors. Previous studies have often focused on taxonomic levels, potentially overlooking important within-group ecological variations. Anurans, with six distinct ecotypes, each occupying unique habitats, serve as an ideal model to examine how environmental factors shape these ecotype-specific distributions. Here, we investigated the global distribution and environmental determinants of anuran ecotypes to reveal diversity patterns, assess their contributions to overall anuran richness, and identify key environmental drivers. Using microhabitat and geographic data from 6088 anuran species, we mapped the richness and relative richness of each ecotype and evaluated the correlation between ecotype distributions and overall anuran diversity. We further used a random forest model to analyze the impact of environmental factors on the distribution patterns of each ecotype. The results showed significant diversity and distributional differences across ecotypes. Terrestrial and arboreal species, comprising 38.44% and 41.19% of total richness, respectively, contributed strongly to anuran diversity patterns (correlation up to 0.96), while other ecotypes showed weaker correlations. The impacts of environmental factors varied across ecotypes and even had contrasting effects among them. Our findings underscore the importance of accounting for ecotype differences within taxa to accurately understand biodiversity distribution patterns, as environmental influences on anuran diversity are strongly ecotype-dependent.