Functional diversity drives the nonlinear relationship between tree species richness and soil denitrification in young subtropical forests

This dataset contains data from a comprehensive large-scale experiment conducted in subtropical forests, investigating how tree species richness and its mediation by functional structure (functional identity and diversity) influence soil denitrification potential (DNP). The study found a unimodal relationship between tree species richness and DNP, with the peak at four species. This pattern was driven by functional diversity (functional dispersion of leaf dry matter content), which enhanced community productivity (ground basal area) and indirectly elevated DNP via increased soil moisture, nirK gene abundance, and reduced soil C:N ratios. Functional identity also significantly impacted DNP, with communities dominated by resource-conservative species exhibiting stronger denitrification.