Background/Question/Methods
Net primary productivity (NPP) is an important indicator of ecosystem functioning. How NPP responds to global environmental change is a central issue in global change ecology. To date, lots of experimental and modeling studies have been carried out to investigate responses of NPP to multiple global change factors, such as warming, CO2 enrichment, drought, irrigation and nitrogen (N) addition. Some studies suggested that N addition could substantially stimulate NPP and would interact with other global change factors. However, there still lacks strong evidence whether responses of NPP to multi-factor are N-limiting globally. In this study, we conducted a meta-analysis in combination with global model outputs under global change to examine whether and how N limitation controls global NPP.
Results/Conclusions
Our meta-analysis results showed that NPP under N addition was relatively higher than that without N addition in response to other multi-factor global change, irrespective of ecosystem types. Modeling results confirmed that N limitation also occurred on NPP globally in response to multiple global change These results highlighted the prevalent role of N limitation on NPP, suggesting that the ability of terrestrial ecosystem to mitigate global change will largely depend on N deposition and fertilization in the future.