Climatic role of terrestrial ecosystem under elevated CO2: a bottom‐up greenhouse gases budget. (7th May 2018)

• Record Type: Journal Article
• Authors: Liu, Shuwei; Ji, Cheng; Wang, Cong; Chen, Jie; Jin, Yaguo; Zou, Ziheng; Li, Shuqing; Niu, Shuli; Zou, Jianwen
• Editors: Knops, Johannes
• Is Part Of: Ecology letters. Volume 21:Number 7(2018)
• Page Start: 1108
• Page End: 1118
• Publication Date: 2018-05-07
• Subjects: Climate change -- elevated CO2 -- greenhouse gas -- meta‐analysis -- plant C pool -- soil C and N cycle; Ecology -- Periodicals; 577
• DOI: 10.1111/ele.13078
• Languages: English
• ISSNs: 1461-023X

Abstract

Abstract: The net balance of greenhouse gas (GHG) exchanges between terrestrial ecosystems and the atmosphere under elevated atmospheric carbon dioxide (CO2 ) remains poorly understood. Here, we synthesise 1655 measurements from 169 published studies to assess GHGs budget of terrestrial ecosystems under elevated CO2 . We show that elevated CO2 significantly stimulates plant C pool (NPP) by 20%, soil CO2 fluxes by 24%, and methane (CH4 ) fluxes by 34% from rice paddies and by 12% from natural wetlands, while it slightly decreases CH4 uptake of upland soils by 3.8%. Elevated CO2 causes insignificant increases in soil nitrous oxide (N2 O) fluxes (4.6%), soil organic C (4.3%) and N (3.6%) pools. The elevated CO2 ‐induced increase in GHG emissions may decline with CO2 enrichment levels. An elevated CO2 ‐induced rise in soil CH4 and N2 O emissions (2.76 Pg CO2 ‐equivalent year −1 ) could negate soil C enrichment (2.42 Pg CO2 year −1 ) or reduce mitigation potential of terrestrial net ecosystem production by as much as 69% (NEP, 3.99 Pg CO2 year −1 ) under elevated CO2 . Our analysis highlights that the capacity of terrestrial ecosystems to act as a sink to slow climate warming under elevated CO2 might have been largely offset by its induced increases in soil GHGs source strength.