Water availability boosts multidimensional plant diversity in a temperate grassland despite anthropogenic disturbances

Global changes present significant challenges to biodiversity. However, how plant communities respond to climate change under various anthropogenic disturbances, and how different species groups contribute to these responses, remains poorly understood. Using an eight-year dataset from a temperate grassland and a multidimensional diversity framework (taxonomic, functional, and phylogenetic), we explored the interactive effects of climate change and anthropogenic disturbances (grazing, fertilization, and their combination). We found that (1) increasing water availability consistently boosted multidimensional plant diversity over time across all treatments. (2) However, disturbances, particularly their combination, weakened this positive climatic effect. (3) Differentiating the contributions of rare, common, and dominant species revealed contrasting responses to climate drivers, highlighting the importance of a multidimensional assessment. Grazing also heightened the community's sensitivity to climate change. Our study reveals that anthropogenic disturbances fundamentally modify plant community responses to climate change, providing critical insights for biodiversity conservation and sustainable grassland management under future climate scenarios.