A general framework for nitrogen deposition effects on soil respiration in global forests
- Xiaoyu Cen
- Peter Vitousek
- Nianpeng He
- Ben Bond-Lamberty
- Shuli Niu
- Enzai Du
- Kailiang Yu
- Mianhai Zheng
- Kevin Van Sundert
- Elizabeth L. Paulus
- Liyin He
- Li Xu
- Mingxu Li
- Klaus Butterbach-Bahl
2025-12-16
Since the Industrial Revolution, human activities have altered atmospheric nitrogen (N) deposition to global forests, affecting carbon dioxide emissions from soils (soil respiration or SR) – one of the largest land-atmosphere carbon fluxes. However, experimental studies have demonstrated both positive and negative effects of N deposition on SR in global forests, leading to debates on how N deposition increases or decreases SR. We developed a framework for generalizing SR responses to N deposition using synthesized data from 168 N addition experiments worldwide and observed SR across the global natural N deposition gradient. The findings indicate that N deposition decreased SR in 2.9% of global forested areas, particularly in eastern China, western Europe, and the eastern USA. However, the net effect of N deposition increased the global forest SR by ~5% (1.7 ± 0.1 PgC yr –1 ). If N pollution could be effectively controlled, global forest SR would decrease, potentially contributing to a reduction in the terrestrial carbon emissions.