Climatic, ecological, and anthropogenic drivers of mammal diversity in arid and semi-arid regions of China

Mammals are crucial for sustaining ecosystem functions and services, yet their diversity is increasingly threatened in China’s arid and semi-arid regions because of environmental fragility and intensifying human activities. Assessing the diversity of mammal assemblages across taxonomic, phylogenetic, and functional dimensions improves the understanding of biodiversity maintenance and community assembly in drylands. Here, these three dimensions of biodiversity and their respective community structures were quantified, and these metrics were linked to modern climate, climate change since the Last Glacial Maximum (LGM; ~21 ka), elevation range, anthropogenic disturbance, and plant species richness. The two variables most strongly associated with taxonomic, phylogenetic, and functional diversity were plant species richness and annual precipitation; land-use change 1900–1950 and mean annual temperature; and glacial–interglacial precipitation change and plant species richness, respectively. For phylogenetic and functional structure, the leading predictors were, respectively, land-use change 1900–1950 and annual precipitation, and annual precipitation and elevation range. Overall, mammal diversity patterns in arid and semi-arid China reflect the interacting effects of contemporary and historical climate, environmental heterogeneity, land-use change, and plant diversity. These results improve the mechanistic understanding of biodiversity maintenance in drylands and provide a scientific basis for conservation planning under future climate change and human disturbance. Mammal diversity was assessed across China’s arid and semi-arid regions. China’s drylands contained 33% of China’s mammal species but 52% of its phylogenetic diversity and 85% of its functional diversity. Taxonomic, phylogenetic, and functional diversity showed clear spatial mismatches. Plant species richness, modern climate, environmental heterogeneity, and land-use change shaped different diversity facets. Conservation planning in drylands should move beyond species richness alone.