Increased diversity by cushion plants enhances alpine community productivity and stability

The relationship between biodiversity and ecosystem functioning is well documented in multiple ecosystems such as grasslands and forests, yet in harsh alpine environments where the formation and maintenance of diversity face significant challenges, it remains largely underexplored. This study examines the role of multiple alpine cushion plant species in promoting plant diversity and enhancing ecosystem functioning through assessments of community biomass production and spatial stability. Cushion-constructed microcommunities (CCMC) exhibit a substantial increase in plant species richness, ranging from 83% to 150%, compared to bare ground areas. These benefits are contingent on the facilitation strength of specific cushions and decrease with distance from the cushion edges. Importantly, the enhanced plant diversity within CCMCs strengthens the positive relationships between diversity and community biomass production and stability through complementarity effects. This increased microcommunity scale diversity is essential for supporting and sustaining ecosystem functioning and stability. These insights advance our understanding of the ecological significance of multiple cushion plant species, demonstrating their joint role in not only sustaining local diversity but also enhancing ecosystem functioning (specifically community productivity) and stability in alpine environments.