Winter precipitation and snow accumulation drive the methane sink or source strength of Arctic tussock tundra.
作者： Elena Blanc-Betes , Jeffrey M. Welker , Neil C. Sturchio , Jeffrey P. Chanton , Miquel A. Gonzalez-Meler
DOI: 10.1111/GCB.13242
关键词:
摘要: Arctic winter precipitation is projected to increase with global warming, but some areas will experience decreases in snow accumulation. Although CH4 emissions may represent a significant climate forcing feedback, long-term impacts of changes accumulation on fluxes remain uncertain. We measured ecosystem and soil CO2 concentrations (13) C composition investigate the metabolic pathways transport mechanisms driving moist acidic tundra flux over growing season (Jun-Aug) after 18 years experimental depth increases decreases. Deeper increased wetness reducing %O2 levels increasing thaw depth. Soil moisture, through saturation, determined predominance methanotrophy or methanogenesis, temperature regulating sink source strength. Reduced (RS) fraction oxidized (Fox) by 75-120% compared Ambient, switching system from small net (21 ± 2 -31 ± 1 mg CH4 m(-2) season(-1) at Ambient RS). reduced Fox 35-40% 90-100% medium- (MS) high- (HS) additions relative contributing strength (464 ± 15 3561 ± 97 mg CH4 MS HS). Decreases deeper were partly due plant-mediated associated expansion tall graminoids. enhanced production within newly thawed soils, responding mainly warming rather than acetate fermentation expected thaw-induced SOC availability. Our results suggest that tundra, resulting positive feedback change depend balance between more less they are currently facing.
sci-hub.se 参考文章(118)
AL Greenup, MA Bradford, NP McNamara, Phil Ineson, JA Lee, The role of Eriophorum vaginatum in CH4 flux from an ombrotrophic peatland Plant and Soil. ,vol. 227, pp. 265- 272 ,(2000) , 10.1023/A:1026573727311
C.L. Ping, G.J. Michaelson, J.M. Kimble, Carbon storage along a latitudinal transect in Alaska Nutrient Cycling in Agroecosystems. ,vol. 49, pp. 235- 242 ,(1997) , 10.1023/A:1009731808445
DOROTHY KELKER, JEFFREY CHANTON, The effect of clipping on methane emissions from Carex Biogeochemistry. ,vol. 39, pp. 37- 44 ,(1997) , 10.1023/A:1005866403120
J. M. Welker, J. T. Fahnestock, M. H. Jones, Annual CO2 Flux in Dry and Moist Arctic Tundra: Field Responses to Increases in Summer Temperatures and Winter Snow Depth Climatic Change. ,vol. 44, pp. 139- 150 ,(2000) , 10.1023/A:1005555012742
G. Brooks Avery, Robert D. Shannon, Jeffrey R. White, Christopher S. Martens, Marc J. Alperin, Controls on methane production in a tidal freshwater estuary and a peatland: methane production via acetate fermentation and CO2 reduction Biogeochemistry. ,vol. 62, pp. 19- 37 ,(2003) , 10.1023/A:1021128400602
Reinoud Segers, Methane production and methane consumption: a review of processes underlying wetland methane fluxes. Biogeochemistry. ,vol. 41, pp. 23- 51 ,(1998) , 10.1023/A:1005929032764
Mark E. Hines, Khrystyne N. Duddleston, Juliette N. Rooney-Varga, Dana Fields, Jeffrey P. Chanton, Uncoupling of acetate degradation from methane formation in Alaskan wetlands: Connections to vegetation distribution Global Biogeochemical Cycles. ,vol. 22, pp. n/a- n/a ,(2008) , 10.1029/2006GB002903
D M Lawrence, C D Koven, S C Swenson, W J Riley, A G Slater, Permafrost thaw and resulting soil moisture changes regulate projected high-latitude CO2 and CH4 emissions Environmental Research Letters. ,vol. 10, pp. 094011- ,(2015) , 10.1088/1748-9326/10/9/094011
James L. Prater, Jeffrey P. Chanton, Gary J. Whiting, Variation in methane production pathways associated with permafrost decomposition in collapse scar bogs of Alberta, Canada Global Biogeochemical Cycles. ,vol. 21, ,(2007) , 10.1029/2006GB002866
Caitlin E. Hicks Pries, E. A. G. Schuur, Jason G. Vogel, Susan M. Natali, Moisture drives surface decomposition in thawing tundra Journal of Geophysical Research: Biogeosciences. ,vol. 118, pp. 1133- 1143 ,(2013) , 10.1002/JGRG.20089