Abstract

The ongoing biodiversity crisis is driven by global climate change, like extreme snowstorm and overgrazing, that alters community composition, necessitating a better understanding of community assembly. We investigated the effects of 15-year experimental grazing and snow addition on taxonomic, phylogenetic, and functional diversity on the Tibetan Plateau. Grazing did not alter community structure, but snow addition caused phylogenetic structure to go from randomness to over-dispersion, as lost species were phylogenetically more closely related to residents than to gained species. Functional community clustering remained unchanged due to opposing trends in individual traits. Moreover, functional traits served as a powerful tool underpinning diversity change. Particularly, species with higher leaf dry matter content and lower specific leaf area, which signify a conservative resource-use strategy, had an increased risk of loss and contributed to changes in community structure under snow addition. Finally, this research offers deeper insights into long-term plant dynamics under environmental changes.