Global atmospheric nitrogen (N) deposition has dramatically increased. Elevated N deposition is likely to change global carbon (C) cycles. As the second-largest world economy, the latest data show that Chinese rapid development has caused serious environmental issues. 

N deposition in China has been among the greatest globally. Hence, the degree of N deposition and its potential effects on the C cycle in Chinese terrestrial ecosystems should be different and especially concerned. 

Researchers in the South China Botanical Garden, Chinese Academy of Sciences (SCBG), Institute of Subtropical Agriculture, Chinese Academy of Sciences (ISA), Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences (IGSNRR), University of Copenhagen, Institute of Botany, Chinese Academy of Sciences (IB) and Sino-Danish Center for Education and Research used a meta-analysis technique to compile 88 studies to synthesize the N deposition impacts on C dynamics in Chinese terrestrial ecosystems. 

The researchers observed a large decrease in below-ground plant C pool and found that N addition did not change soil C pools but increased above-ground plant C pool. "The impacts of N addition on ecosystem C dynamics depend on ecosystem type and rate of N." said lead researcher Dr CHEN Hao from ISA. Besides, they suggest that (1) decreased below-ground plant C pool may limit long-term soil C sequestration; and (2) it is better to treat N-rich and N-limited ecosystems differently in modeling effects of N deposition on ecosystem C cycle. 

The research was supported by the National Basic Research Program of China (2010CB833502) and the National Natural Science Foundation of China (41473112). 

The study entitled "Effects of nitrogen deposition on carbon cycle in terrestrial ecosystems of China: A meta-analysis" has been published in Volume 206, Issue 2015 of Environmental Pollution, details could be found at http://www.sciencedirect.com/science/article/pii/S0269749115003668 

Contact: LI Dejun 

E-mail: dejunli@isa.ac.cn 

Institute of Subtropical Agriculture, Chinese Academy of Sciences