Global warming and precipitation changes drive divergent responses of soil microbial nitrogen and phosphorus limitation

Microbial nutrient limitation regulates terrestrial carbon-nutrient feedbacks, yet its dynamic response to climate forcing remains poorly constrained. Here we synthesized 183 field experiments and used ecoenzymatic stoichiometry to quantify treatment-induced changes in microbial nitrogen limitation (ΔMNL) and phosphorus limitation (ΔMPL) relative to controls. Neither ΔMNL nor ΔMPL showed a consistent response across warming and precipitation treatments. Nevertheless, ΔMPL was more predictable than ΔMNL and was primarily associated with precipitation change, background precipitation, aridity and climatic seasonality. By contrast, ΔMNL was weakly explained by predictors and was more sensitive to soil texture, soil C and resource conditions. Future projections suggest a widespread decline in microbial P limitation across terrestrial ecosystems, especially in tropical regions, parts of the Southern Hemisphere, and grassland, shrubland and tundra. Our results underscore hydroclimatic context as a pivotal determinant of microbial P-acquisition responses to climate change.