Higher microbial community stability promotes the link between biodiversity and multifunctionality under environmental changes

Unravelling the community stability under a changing climate and its effects on the relationships between biodiversity and ecosystem functions (BEF) is a challenging topic in theoretical ecology, which remains understudied in the field of microbial ecology. Here, we collected soils from 50 agricultural fields to investigate the response of soil organisms and functions to environmental changes, and evaluated the influence of community stability on the BEF relationships. We observed that fungi exhibited higher stability than bacteria and protists across multiple dimensions, including taxonomic diversity, community composition, and network structure, and showed stronger correlations with key ecosystem functions. Notably, positive BEF relationships persisted under multiple global change stressors, including warming, dry–wet cycles, and nutrient addition, and their strength increased under these conditions. Furthermore, random forest and structural equation modeling analyses revealed that higher microbial community stability significantly enhanced BEF relationships. Together, our findings highlight that soil microbial community stability plays a critical role in shaping BEF relationships in agricultural ecosystems undergoing environmental change. These results suggest that maintaining or enhancing microbial community stability should be considered a key strategy for promoting ecosystem sustainability under global change scenarios.