Skip to Main Content
Environmental and physical controls on northern high latitude methane fluxes across permafrost zonesAuthor(s): D. Olefeldt; M.R. Turetsky; P.M. Crill; A.D. McGuire
Source: Global Change Biology
Publication Series: Scientific Journal (JRNL)
Station: Pacific Northwest Research Station
Download Publication (1.03 MB)
DescriptionMethane (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.
- Visit PNW's Publication Request Page to request a hard copy of this publication.
- We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
- This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
CitationOlefeldt, D.; Turetsky, M.R.; Crill, P.M.; McGuire, A.D. 2013. Environmental and physical controls on northern high latitude methane fluxes across permafrost zones. Global Change Biology. 19: 589-603.
KeywordsMethane, permafrost, sedges, static chambers, tundra, wetlands
- Controls on ecosystem and root respiration across a permafrost and wetland gradient in interior Alaska
- Wetland succession in a permafrost collapse: interations between fire and thermokarst
- Response of plant community structure and primary productivity to experimental drought and flooding in an Alaskan fen
XML: View XML