Tree diversity effects on litter decomposition are mediated by litterfall and microbial processes

Forest ecosystems are critical for their carbon sequestration potential. Increasing tree diversity has been shown to enhance both forest productivity and litter decomposition. Litter increases decomposability by increasing the of substrates offered decomposers. However, relative importance decomposer community in mediating effects on decomposition remains unknown. Moreover, modulation litterfall spatial distribution, consequently decomposition, rarely tested. We studied leaf its mediation amount litterfall, species richness decomposability, soil microorganisms a large-scale experiment subtropical China. Furthermore, we examined how functional identity affect decomposability. Finally, tested traits, biomass, structure drive distribution. found evidence that increased litterfall. showed this perform 84–87% changes microbial explained 19–37% variance. Additionally, up 20% variance was while itself determined identity, diversity, richness. Tree (+200% from monoculture eight-species neighborhood). further demonstrated species-specific with proximity modulated traits. These drivers heterogeneity thus highlighted multiple biomass- diversity-mediated ecosystem properties driving nutrient cycling. conclude considering variability biotic will improve our mechanistic understanding functioning.