title: A pan-Arctic synthesis of CH4and CO2production from anoxic soil incubations.
abstract: Permafrost thaw can alter the soil environment through changes in soil moisture, frequently resulting in soil saturation, a shift to anaerobic decomposition, and changes in the plant community. These changes, along with thawing of previously frozen organic material, can alter the form and magnitude of greenhouse gas production from permafrost ecosystems. We synthesized existing methane (CH4) and carbon dioxide (CO2) production measurements from anaerobic incubations of boreal and tundra soils from the geographic permafrost region to evaluate large-scale controls of anaerobic CO2and CH4production and compare the relative importance of landscape-level factors (e.g., vegetation type and landscape position), soil properties (e.g., pH, depth, and soil type), and soil environmental conditions (e.g., temperature and relative water table position). We found fivefold higher maximum CH4production per gram soil carbon from organic soils than mineral soils. Maximum CH4production from soils in the active layer (ground that thaws and refreezes annually) was nearly four times that of permafrost per gram soil carbon, and CH4production per gram soil carbon was two times greater from sites without permafrost than sites with permafrost. Maximum CH4and median anaerobic CO2production decreased with depth, while CO2:CH4production increased with depth. Maximum CH4production was highest in soils with herbaceous vegetation and soils that were either consistently or periodically inundated. This synthesis identifies the need to consider biome, landscape position, and vascular/moss vegetation types when modeling CH4production in permafrost ecosystems and suggests the need for longer-term anaerobic incubations to fully capture CH4dynamics. Our results demonstrate that as climate warms in arctic and boreal regions, rates of anaerobic CO2and CH4production will increase, not only as a result of increased temperature, but also from shifts in vegetation and increased ground saturation that will accompany permafrost thaw.
authors.affiliation: Earth Systems Research Center, Institute for the Study of Earth, Oceans & Space, University of New Hampshire, 8 College Road, Durham, 03824, NH, USA.
authors.forename: Claire C
authors.identifier: http://orcid.org/0000-0002-1225-8178
authors.initials: CC
authors.lastname: Treat
authors.affiliation: Woods Hole Research Center, 149 Woods Hole Road, Falmouth, 02540, MA, USA.
authors.forename: Susan M
authors.initials: SM
authors.lastname: Natali
authors.affiliation: Natural Resource Ecology Laboratory, Colorado State University, Fort Collins, CO, USA.
authors.forename: Jessica
authors.identifier: http://orcid.org/0000-0002-4493-2489
authors.initials: J
authors.lastname: Ernakovich
authors.affiliation: Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, One Bethel Valley Road Building 1062, Oak Ridge, 37831-6422, TN, USA.
authors.forename: Colleen M
authors.initials: CM
authors.lastname: Iversen
authors.affiliation: Department of Earth System Science, University of California, Croul Hall, Irvine, 92697, CA, USA.
authors.forename: Massimo
authors.initials: M
authors.lastname: Lupascu
authors.affiliation: U.S. Geological Survey, Alaska Cooperative Fish and Wildlife Research Unit, University of Alaska Fairbanks, 214 Irving I Builidng, Fairbanks, 99775, AK, USA.
authors.forename: Anthony David
authors.initials: AD
authors.lastname: McGuire
authors.affiliation: Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, One Bethel Valley Road Building 1062, Oak Ridge, 37831-6422, TN, USA.
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Norby
authors.affiliation: Biosciences Division, Oak Ridge National Laboratory, 1 Bethel Valley Road MS 6038, Oak Ridge, 37830, TN, USA.
authors.forename: Taniya
authors.initials: T
authors.lastname: Roy Chowdhury
authors.affiliation: Department of Microbiology and Ecosystem Science, University of Vienna, Althenstrasse 14, 1090, Vienna, Austria.|Austrian Polar Research Institute, Althenstrasse 14, 1090, Vienna, Austria.
authors.forename: Andreas
authors.initials: A
authors.lastname: Richter
authors.affiliation: Department of Ecosystem Biology, University of South Bohemia, Branisovska 31, České Budějovice, 37005, Czech Republic.
authors.forename: Hana
authors.initials: H
authors.lastname: Šantrůčková
authors.affiliation: Department of Biology, University of Florida, 421 Carr Hall, PO Box 118525, Gainesville, FL, 32611, USA.
authors.forename: Christina
authors.initials: C
authors.lastname: Schädel
authors.affiliation: Department of Biology, University of Florida, 421 Carr Hall, PO Box 118525, Gainesville, FL, 32611, USA.
authors.forename: Edward A G
authors.initials: EAG
authors.lastname: Schuur
authors.affiliation: Environmental Sciences Division and Climate Change Science Institute, Oak Ridge National Laboratory, One Bethel Valley Road Building 1062, Oak Ridge, 37831-6422, TN, USA.
authors.forename: Victoria L
authors.initials: VL
authors.lastname: Sloan
authors.affiliation: Department of Integrative Biology, University of Guelph, Science Complex, Guelph, N1G 1G2, ON, Canada.
authors.forename: Merritt R
authors.initials: MR
authors.lastname: Turetsky
authors.affiliation: U.S. Geological Survey, 345 Middlefield Rd, MS 962, Menlo Park, 94025, CA, USA.
authors.forename: Mark P
authors.initials: MP
authors.lastname: Waldrop
keywords: anaerobic incubation; arctic; boreal; carbon dioxide; climate change; methane; permafrost