Microbial CUE

We found that CUEex decreased with absolute latitude, while CUEen showed the opposite trend. Warming reduced CUEex and CUEen by 3.6% and 16.5%, respectively. Drought increased CUEex by 7.9%, but decreased CUEen by 14.3%. Nutrient inputs consistently decreased CUEex by 5.0-17.1%, while nitrogen and nitrogen combined with phosphorus and potassium inputs increased CUEen by 25.5% and 43.1%, respectively. Aridity index, soil pH, and cation exchange capacity were the main factors influencing microbial CUEex. In contrast, microbial respiration and growth rates, followed by microbial biomass, were the major predictors of microbial CUEen. Main conclusions: Biogeochemical models should account for the opposite spatial patterns of microbial CUEex and CUEen, as well as their respective specific drivers under global changes, to accurately predict microbial responses to various carbon sources.