Global patterns of nutrient limitation in soil microorganisms
Yongxing Cui, Shushi Peng, Matthias C. Rillig, Tessa Camenzind, Manuel Delgado‐Baquerizo, César Terrer, Xiaofeng Xu, Maoyuan Feng, Mengjie Wang, Linchuan Fang, Biao Zhu, Enzai Du, Daryl Moorhead, Robert L. Sinsabaugh, Josep Peñuelas, James J. Elser
Abstract
The availability of nitrogen (N) and phosphorus (P) is essential for soil microbial activity and growth, yet global patterns of N and P limitation in soil microbial metabolism remain largely unknown. We modeled ecoenzyme stoichiometry data from 5,259 field observations of natural ecosystems to assess microbial N and P limitation in global surface soils. We found that microbial P limitation, which was especially strong at low latitudes, was more prevalent globally than microbial N limitation, which prevailed in cold environments. We also found widespread N and P colimitation in soil microorganisms in the tropics, contradicting the long-held paradigm that P, and not N, is the primary limiting nutrient at low latitudes. This colimitation could be attributable to elevated microbial N demand for the synthesis of P-acquiring enzymes under P limitation. Upscaling (0.1 × 0.1° spatial resolution) suggested that soil microorganisms were limited by N and P in 39% and 57%, respectively, of natural terrestrial surface areas, with 21% of areas with N and P colimitation. As a global assessment of spatial variation in microbial N and P limitation, our results highlight the importance of N availability in supporting microbial P acquisition at low latitudes and improve our understanding of microbial nutrient limitation on a global scale.