title: Responses of ecosystem carbon cycle to experimental warming: a meta-analysis.
abstract: Global warming potentially alters the terrestrial carbon (C) cycle, likely feeding back to further climate warming. However, how the ecosystem C cycle responds and feeds back to warming remains unclear. Here we used a meta-analysis approach to quantify the response ratios of 18 variables of the ecosystem C cycle to experimental warming and evaluated ecosystem C-cycle feedback to climate warming. Our results showed that warming stimulated gross ecosystem photosynthesis (GEP) by 15.7%, net primary production (NPP) by 4.4%, and plant C pools from above- and belowground parts by 6.8% and 7.0%, respectively. Experimental warming accelerated litter mass loss by 6.8%, soil respiration by 9.0%, and dissolved organic C leaching by 12.1%. In addition, the responses of some of those variables to experimental warming differed among the ecosystem types. Our results demonstrated that the stimulation of plant-derived C influx basically offset the increase in warming-induced efflux and resulted in insignificant changes in litter and soil C content, indicating that climate warming may not trigger strong positive C-climate feedback from terrestrial ecosystems. Moreover, the increase in plant C storage together with the slight but not statistically significant decrease of net ecosystem exchange (NEE) across ecosystems suggests that terrestrial ecosystems might be a weak C sink rather than a C source under global climate warming. Our results are also potentially useful for parameterizing and benchmarking land surface models in terms of C cycle responses to climate warming.
authors.affiliation: Coastal Ecosystems Research Station of the Yangtze River Estuary, Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, Institute of Biodiversity Science, Fudan University, 220 Handan Road, Shanghai 200433 China.
authors.forename: Meng
authors.initials: M
authors.lastname: Lu
authors.forename: Xuhui
authors.initials: X
authors.lastname: Zhou
authors.forename: Qiang
authors.initials: Q
authors.lastname: Yang
authors.forename: Hui
authors.initials: H
authors.lastname: Li
authors.forename: Yiqi
authors.initials: Y
authors.lastname: Luo
authors.forename: Changming
authors.initials: C
authors.lastname: Fang
authors.forename: Jiakuan
authors.initials: J
authors.lastname: Chen
authors.forename: Xin
authors.initials: X
authors.lastname: Yang
authors.forename: Bo
authors.initials: B
authors.lastname: Li
mesh_terms: D001419:Bacteria / Q000254:growth & development / Q000378:metabolism; D018533:Biomass; D057486:Carbon Cycle; D057231:Climate Change; D017753:Ecosystem; D004784:Environmental Monitoring; D010788:Photosynthesis; D035261:Plant Components, Aerial / Q000254:growth & development; D018517:Plant Roots / Q000254:growth & development; D012987:Soil / Q000737:chemistry
chemical_list: D012987:Soil