Updated Chorotypes of Terrestrial Vertebrates Shed New Light on Zoogeographical Regions in China

The chorotype, a group of species with similar distributions, provides critical insights into biogeographical patterns. Despite recent advances in taxonomic discovery and revision, one-third of terrestrial vertebrates in China remain unclassified into established chorotypes, hindering understanding of the zoogeographical patterns in China. Here, we updated chorotype classifications and renewed the zoogeographical regions for terrestrial vertebrates in China based on distribution data for 3059 species (638 mammals, 1298 birds, 563 reptiles, and 560 amphibians). We constructed a presence‒absence matrix using 1° × 1° grid cells and assigned species chorotypes to a predefined chorotype framework. Based on the proportions of species chorotypes within each grid cell, we constructed a dissimilarity matrix and used hierarchical clustering to delineate zoogeographical regions of terrestrial vertebrates in China. Discriminant analysis achieved high cross-validation accuracy for chorotype assignment across taxa. Among the 1040 newly updated species, Southern China and Himalaya‒Hengduan Mountains chorotypes played dominant roles, and most of them were reptiles and amphibians. Cluster analysis identified eight zoogeographical regions: North China, Northeast China, the Qiangtang Plateau, Northwest China, South China, Chinese Taiwan Island, the Yungui Plateau, and the Himalaya‒Hengduan Mountains. Despite the broad transition zones in eastern China with mixed chorotypes, the Qinling‒Huaihe Line emerged as the Palearctic‒Oriental boundary. Our study provides the first quantitative update of chorotypes for terrestrial vertebrate species in China, validated through the Grade of Membership model, and renews the zoogeographical regions. Mapping geographical patterns of chorotype proportion is promising for exploring biotic transition zones and offers a reliable framework for delineating biogeographical regions.