气候变化领域集成服务门户(CCPortal): Changes in peat chemistry associated with permafrost thaw increase greenhouse gas production

CCPortal

DOI	10.1073/pnas.1314641111
	Changes in peat chemistry associated with permafrost thaw increase greenhouse gas production
	Hodgkins S.B.; Tfaily M.M.; McCalley C.K.; Logan T.A.; Crill P.M.; Saleska S.R.; Rich V.I.; Chanton J.P.
发表日期	2014
ISSN	0027-8424
起始页码	5819
结束页码	5824
卷号	111 期号:16
英文摘要	Carbon release due to permafrost thaw represents a potentially major positive climate change feedback. The magnitude of carbon loss and the proportion lost as methane (CH4) vs. carbon dioxide (CO2) depend on factors including temperature, mobilization of previously frozen carbon, hydrology, and changes in organic matter chemistry associated with environmental responses to thaw. While the first three of these effects are relatively well understood, the effect of organic matter chemistry remains largely unstudied. To address this gap, we examined the biogeochemistry of peat and dissolved organic matter (DOM) along a ∼40-y permafrost thaw progression from recently- to fully thawed sites in Stordalen Mire (68.35°N, 19.05°E), a thawing peat plateau in northern Sweden. Thaw-induced subsidence and the resulting inundation along this progression led to succession in vegetation types accompanied by an evolution in organic matter chemistry. Peat C/N ratios decreased whereas humification rates increased, and DOM shifted toward lower molecular weight compounds with lower aromaticity, lower organic oxygen content, and more abundant microbially produced compounds. Corresponding changes in decomposition along this gradient included increasing CH4 and CO2 production potentials, higher relative CH4/CO 2 ratios, and a shift in CH4 production pathway from CO2 reduction to acetate cleavage. These results imply that subsidence and thermokarst-associated increases in organic matter lability cause shifts in biogeochemical processes toward faster decomposition with an increasing proportion of carbon released as CH4. This impact of permafrost thaw on organic matter chemistry could intensify the predicted climate feedbacks of increasing temperatures, permafrost carbon mobilization, and hydrologic changes.
语种	英语
scopus关键词	carbon; carbon dioxide; dissolved organic matter; methane; peat; article; biogeochemistry; carbon footprint; controlled study; decomposition; greenhouse gas; habitat; humification; methanogenesis; molecular size; molecular weight; nonhuman; organic chemistry; peatland; permafrost; pH; plant community; priority journal; Sphagnum; Sweden; thawing; vegetation; water table
来源期刊	Proceedings of the National Academy of Sciences of the United States of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/158988
作者单位	Hodgkins, S.B., Department of Earth, Ocean, and Atmospheric Science, Florida State University, Tallahassee, FL 32306, United States; Tfaily, M.M., Department of Earth, Ocean, and Atmospheric Science, Florida State University, Tallahassee, FL 32306, United States; McCalley, C.K., Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ 85721, United States; Logan, T.A., Abisko Scientific Research Station, Swedish Polar Research Secretariat, SE-981 07 Abisko, Sweden; Crill, P.M., Department of Geological Sciences, Stockholm University, SE-106 91 Stockholm, Sweden; Saleska, S.R., Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ 85721, United States; Rich, V.I., Department of Soil, Water and Environmental Science, University of Arizona, Tucson, AZ 85721, United States; Chanton, J.P., Department of Earth, Ocean, and Atmospheric Science, Florida State University, Tallahassee, FL 32306, United States
推荐引用方式 GB/T 7714	Hodgkins S.B.,Tfaily M.M.,McCalley C.K.,et al. Changes in peat chemistry associated with permafrost thaw increase greenhouse gas production[J],2014,111(16).
APA	Hodgkins S.B..,Tfaily M.M..,McCalley C.K..,Logan T.A..,Crill P.M..,...&Chanton J.P..(2014).Changes in peat chemistry associated with permafrost thaw increase greenhouse gas production.Proceedings of the National Academy of Sciences of the United States of America,111(16).
MLA	Hodgkins S.B.,et al."Changes in peat chemistry associated with permafrost thaw increase greenhouse gas production".Proceedings of the National Academy of Sciences of the United States of America 111.16(2014).