Patterns and drivers of taxonomic, phylogenetic and functional diversity of understory bird communities in Chinese forests captured by camera traps

Abstract Birds are important in regulating and maintaining forest ecosystem functioning and services, which are threatened by human activities in the Anthropocene. Camera traps are now widely used to monitor forest bird diversity. But few studies have tested forest bird diversity distribution patterns based on camera traps, especially from the phylogenetic and functional perspectives. Here, we linked the taxonomic, phylogenetic and functional diversity of Chinese forest bird communities captured by camera traps with contemporary climate, glacial-interglacial climate change, and elevational range. Our results showed that 2701 cameras in 58 forest sites captured 290 bird species, most of which were ground-dwelling species and the species number was 21% of all Chinese bird species. Notably, the phylogenetic and functional diversity of these understory birds was 28% and 51% of all Chinese birds, respectively. There were also eight endangered species, 13 vulnerable species, and 37 near threatened species among the 290 species. In addition, forest sites with relatively stable glacial-interglacial climate had relatively higher species richness, but lower phylogenetic and functional diversity. Phylogenetic diversity was also negatively associated with elevational range, while functional diversity was negatively associated with contemporary temperature and precipitation. These findings suggest that camera traps could be an effective technology for forest bird monitoring and conservation, especially for the understory species. In addition, forest in regions with relatively stable paleoclimate, warm and wet contemporary climate, and large elevational range may harbor more bird species through recent rapid in situ diversification.