The uncertain climate footprint of wetlands under human pressure
Publication in refereed journal



摘要Significant climate risks are associated with a positive carbon-temperature feedback in northern latitude carbon-rich ecosystems, making an accurate analysis of human impacts on the net greenhouse gas balance of wetlands a priority. Here, we provide a coherent assessment of the climate footprint of a network of wetland sites based on simultaneous and quasi-continuous ecosystem observations of CO2 and CH4 fluxes. Experimental areas are located both in natural and in managed wetlands and cover a wide range of climatic regions, ecosystem types, and management practices. Based on direct observations we predict that sustained CH4 emissions in natural ecosystems are in the long term (i.e., several centuries) typically offset by CO2 uptake, although with large spatiotemporal variability. Using a space-for-time analogy across ecological and climatic gradients, we represent the chronosequence from natural to managed conditions to quantify the "cost" of CH4 emissions for the benefit of net carbon sequestration. With a sustained pulseresponse radiative forcing model, we found a significant increase in atmospheric forcing due to land management, in particular for wetland converted to cropland. Our results quantify the role of human activities on the climate footprint of northern wetlands and call for development of active mitigation strategies for managed wetlands and new guidelines of the Intergovernmental Panel on Climate Change (IPCC) accounting for both sustained CH4 emissions and cumulative CO2 exchange.
著者Petrescu AMR, Lohila A, Tuovinen JP, Baldocchi DD, Desai AR, Roulet NT, Vesala T, Dolman AJ, Oechel WC, Marcolla B, Fribor T, Rinne J, Matthes JH, Merbold L, Meijide A, Kiely G, Sottocornola M, Sachs T, Zona D, Varlagin A, Lai DYF, Veenendaal E, Parmentier FJW, Skiba U, Lund M, Hensen A, Van Huissteden J, Flanagan LB, Shurpali NJ, Grunwald T, Humphreys ER, Jackowicz-Korczynski M, Aurela MA, Laurila T, Gruning C, Corradi CAR, Schrier-Uijl AP, Christensen TR, Tamstorf MP, Mastepanov M, Martikainen PJ, Verma SB, Bernhofer C, Cescatti A
期刊名稱Proceedings of the National Academy of Sciences
頁次4594 - 4599
關鍵詞carbon dioxide; methane; radiative forcing; wetland conversion
Web of Science 學科類別Multidisciplinary Sciences; Science & Technology - Other Topics

上次更新時間 2020-24-11 於 23:59