Habitat-specific conservation priorities of multidimensional diversity patterns of amphibians in China effectively contribute to the ‘3030’ target

Amphibia is the most threatened animal group among all land vertebrates in the context of anthropogenic global change. Filling the conservation gaps for this taxonomic group could help achieve the ambitious target of covering 30 % of the land by 2030 ('3030' target) set by the 15-th meeting of the Conference of the Parties (COP15). In this study, we compiled the most up-to-date occurrence records and corresponding species-specific traits and phylogenies of amphibians in China (particularly those newly described in the past decade) to explore the spatial distribution patterns of multidimensional diversity (including taxonomic, functional, and phylogenetic) for different species groups (including all, endemic and threatened). Additionally, a new conservation gap index (CGI) was proposed and applied to the analysis of multi-objective conservation strategies. The results showed that the spatial distribution of taxonomic, functional and phylogenetic diversity of amphibians in China is markedly geographically diverse, with common hotspots for all three concentrated in the humid mountainous regions of southern China. The CGI, which is independent of arbitrary threshold selection and grid cell size, showed that the conservation gap for amphibians in China is largest in biomes such as tropical and subtropical moist broadleaf forests and temperate broadleaf and mixed forests. The multi-objective conservation analysis revealed that the Yangtze River basin, Pearl River basin and Southeast Basin in China have pivotal roles in achieving the '3030' target due to their high taxonomic, phylogenetic and functional diversity, relatively high proportion of threatened and endemic species, and low coverage of existing nature reserves. Notably, sustainable management of less-protected habitats, including farmlands and grasslands, can reduce the area requirement of strict protection for reaching the '3030' conservation goal. This study provides practical strategies for guiding amphibian conservation by systematically integrating multidimensional biodiversity information, habitat features and the spatial distributions of the existing natural reserves.