DOI: 10.1111/gcb.12071
论文题名: Environmental and physical controls on northern terrestrial methane emissions across permafrost zones
作者: Olefeldt D. ; Turetsky M.R. ; Crill P.M. ; Mcguire A.D.
刊名: Global Change Biology
ISSN: 13541013
出版年: 2013
卷: 19, 期: 2 起始页码: 589
结束页码: 603
语种: 英语
英文关键词: Methane
; Permafrost
; Sedges
; Static chambers
; Tundra
; Wetlands
Scopus关键词: methane
; emission
; methane
; permafrost
; sedge
; terrestrial ecosystem
; tundra
; wetland
; article
; cold
; environmental monitoring
; Cold Temperature
; Environmental Monitoring
; Methane
; Carex
; Carex densa
英文摘要: Methane (CH4) emissions from the northern high-latitude region represent potentially significant biogeochemical feedbacks to the climate system. We compiled a database of growing-season CH4 emissions from terrestrial ecosystems located across permafrost zones, including 303 sites described in 65 studies. Data on environmental and physical variables, including permafrost conditions, were used to assess controls on CH4 emissions. Water table position, soil temperature, and vegetation composition strongly influenced emissions and had interacting effects. Sites with a dense sedge cover had higher emissions than other sites at comparable water table positions, and this was an effect that was more pronounced at low soil temperatures. Sensitivity analysis suggested that CH4 emissions from ecosystems where the water table on average is at or above the soil surface (wet tundra, fen underlain by permafrost, and littoral ecosystems) are more sensitive to variability in soil temperature than drier ecosystems (palsa dry tundra, bog, and fen), whereas the latter ecosystems conversely are relatively more sensitive to changes of the water table position. Sites with near-surface permafrost had lower CH4 fluxes than sites without permafrost at comparable water table positions, a difference that was explained by lower soil temperatures. Neither the active layer depth nor the organic soil layer depth was related to CH4 emissions. Permafrost thaw in lowland regions is often associated with increased soil moisture, higher soil temperatures, and increased sedge cover. In our database, lowland thermokarst sites generally had higher emissions than adjacent sites with intact permafrost, but emissions from thermokarst sites were not statistically higher than emissions from permafrost-free sites with comparable environmental conditions. Overall, these results suggest that future changes to terrestrial high-latitude CH4 emissions will be more proximately related to changes in moisture, soil temperature, and vegetation composition than to increased availability of organic matter following permafrost thaw. © 2012 Blackwell Publishing Ltd. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/62539
Appears in Collections: 影响、适应和脆弱性
There are no files associated with this item.
作者单位: Department of Integrative Biology, University of Guelph, Science Complex, Guelph, ON,N1G 2W1, Canada; Department of Geological Sciences, Stockholm University, Stockholm, SE-106 91, Sweden; US Geological Survey, Alaska Cooperative Fish and Wildlife Research Unit, University of Alaska Fairbanks, Fairbanks, AK, 99775, United States
Recommended Citation:
Olefeldt D.,Turetsky M.R.,Crill P.M.,et al. Environmental and physical controls on northern terrestrial methane emissions across permafrost zones[J]. Global Change Biology,2013-01-01,19(2)