Data from: Deciphering how soil fertility and microbial community structure translate into ecosystem functions in boreal forest floors

Soil microorganisms drive ecosystem processes including carbon cycling. Their functions are simultaneously influenced by microbial community and the environment, but resolving these two sets remains a challenge. Therefore, we conducted transplantation experiments along natural fertility gradients in three boreal forests. One-year soil transplantation altered physicochemical variables (e.g., pH and C:N ratio), significantly changed microbial metabolic rates and biomass turnover, but did not shift community structure, indicating that fertility drove these short-term physiological changes. Despite pronounced differences in physicochemical variables and major shifts in community structures along the natural gradients, microbial metabolic rates and turnover times remained constant. Our findings suggest that restructuring communities to match environmental conditions can maintain the metabolic rates that underpin soil functions. However, microbial carbon use efficiency (CUE) was unaffected by community-environment alignment, and was instead determined by fertility. Thus, community structure and environment jointly affect microbial physiological rates, while CUE is dominated by environmental conditions.