Responses of ecosystem nitrogen cycle to nitrogen addition: a meta-analysis.
• Anthropogenic nitrogen (N) addition may substantially alter the terrestrial N cycle. However, a comprehensive understanding of how the ecosystem N cycle responds to external N input remains elusive. • Here, we evaluated the central tendencies of the responses of 15 variables associated with the ecosystem N cycle to N addition, using data extracted from 206 peer-reviewed papers. • Our results showed that the largest changes in the ecosystem N cycle caused by N addition were increases in soil inorganic N leaching (461%), soil NO₃⁻ concentration (429%), nitrification (154%), nitrous oxide emission (134%), and denitrification (84%). N addition also substantially increased soil NH₄+ concentration (47%), and the N content in belowground (53%) and aboveground (44%) plant pools, leaves (24%), litter (24%) and dissolved organic N (21%). Total N content in the organic horizon (6.1%) and mineral soil (6.2%) slightly increased in response to N addition. However, N addition induced a decrease in microbial biomass N by 5.8%. • The increases in N effluxes caused by N addition were much greater than those in plant and soil pools except soil NO₃⁻, suggesting a leaky terrestrial N system.
Coastal Ecosystems Research Station of the Yangtze River Estuary, Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, The Institute of Biodiversity Science, Fudan University, 220 Handan Road, Shanghai 200433, China.|Department of Botany and Microbiology, University of Oklahoma, Norman, OK 73019, USA.|Department of Environmental Science and Engineering, Fudan University, 220 Handan Road, Shanghai 200433, China.
Meng
M
Lu
Department of Botany and Microbiology, University of Oklahoma, Norman, OK 73019, USA.
Yuanhe
Y
Yang
Coastal Ecosystems Research Station of the Yangtze River Estuary, Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, The Institute of Biodiversity Science, Fudan University, 220 Handan Road, Shanghai 200433, China.|Department of Botany and Microbiology, University of Oklahoma, Norman, OK 73019, USA.
Yiqi
Y
Luo
Coastal Ecosystems Research Station of the Yangtze River Estuary, Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, The Institute of Biodiversity Science, Fudan University, 220 Handan Road, Shanghai 200433, China.
Changming
C
Fang
Department of Botany and Microbiology, University of Oklahoma, Norman, OK 73019, USA.
Xuhui
X
Zhou
Coastal Ecosystems Research Station of the Yangtze River Estuary, Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, The Institute of Biodiversity Science, Fudan University, 220 Handan Road, Shanghai 200433, China.
Jiakuan
J
Chen
Department of Environmental Science and Engineering, Fudan University, 220 Handan Road, Shanghai 200433, China.
Xin
X
Yang
Coastal Ecosystems Research Station of the Yangtze River Estuary, Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, The Institute of Biodiversity Science, Fudan University, 220 Handan Road, Shanghai 200433, China.
Bo
B
Li
D000383:Agriculture; D018533:Biomass; D017753:Ecosystem; D015201:Meta-Analysis as Topic; D008954:Models, Biological; D009584:Nitrogen / Q000378:metabolism*; D058458:Nitrogen Cycle
D009584:Nitrogen