Conclusion

With a combination of a field experiment, a meta-analysis, and an empirical modeling approach we found that the substrate competition theory is most likely the predominant mechanism explaining the P alleviation of the N-suppression of CH4 uptake, and we further estimated that contemporary atmospheric N deposition suppresses the CH4 sink in global grasslands by 11.4% while P deposition alleviates this suppression by 5.8%.
This study is among the first attempts to quantify the P impacts on the N suppression of soil oxidation of atmospheric CH4 in global grasslands. It advocates model development to incorporate P mechanisms not only for the nutrient impacts on carbon cycling, but also for a more accurate projection of the CH4 budget of terrestrial ecosystems.