Multitrophic and Multidimensional Insights into Biodiversity and Functional Trait Responses to Precipitation Changes in Alpine Grasslands.

Biodiversity and functional traits are increasingly recognized as pivotal factors in regulating ecosystem functioning and stability. However, the patterns and processes of multidimensional biodiversity and functional traits along environmental gradients remain insufficiently understood. In this study, we examined taxonomic, phylogenetic, and functional diversity across multiple trophic levels in 38 alpine grassland sites along a precipitation gradient on the Qinghai-Tibet Plateau. Our findings reveal asynchronous responses of taxonomic, phylogenetic, and functional diversity metrics, as well as functional traits across trophic levels, to variations in precipitation. Soil microbial diversity and functional traits exhibited stronger responses to precipitation changes compared to plant communities, with a tighter coupling observed between microbial diversity and microbial functional traits. Climate and soil properties jointly regulated diversity and functional trait metrics, with the climate exerting greater influence on functional traits and soil properties playing a dominant role in shaping diversity patterns. This study highlights the distinct responses of biodiversity and functional trait attributes to environmental shifts, emphasizing the importance of integrating multidimensional and multitrophic perspectives to advance our understanding of community assembly processes.