Journal cover Journal topic
Biogeosciences An interactive open-access journal of the European Geosciences Union
Journal topic
Volume 9, issue 4
Biogeosciences, 9, 1423–1440, 2012
https://doi.org/10.5194/bg-9-1423-2012
© Author(s) 2012. This work is distributed under
the Creative Commons Attribution 3.0 License.

Special issue: Understanding the impacts of hydrological changes on terrestrial...

Biogeosciences, 9, 1423–1440, 2012
https://doi.org/10.5194/bg-9-1423-2012
© Author(s) 2012. This work is distributed under
the Creative Commons Attribution 3.0 License.

Research article 17 Apr 2012

Research article | 17 Apr 2012

Soil moisture control over autumn season methane flux, Arctic Coastal Plain of Alaska

C. S. Sturtevant1, W. C. Oechel1, D. Zona1,2, Y. Kim3, and C. E. Emerson1 C. S. Sturtevant et al.
  • 1Global Change Research Group, Department of Biology, San Diego State University, San Diego, California, USA
  • 2Research Group of Plant and Vegetation Ecology, University of Antwerp, Wilrijk, Belgium
  • 3International Arctic Research Center, University of Alaska Fairbanks, Fairbanks, Alaska, USA

Abstract. Accurate estimates of annual budgets of methane (CH4) efflux in arctic regions are severely constrained by the paucity of non-summer measurements. Moreover, the incomplete understanding of the ecosystem-level sensitivity of CH4 emissions to changes in tundra moisture makes prediction of future CH4 release from the Arctic extremely difficult. This study addresses some of these research gaps by presenting an analysis of eddy covariance and chamber measurements of CH4 efflux and supporting environmental variables during the autumn season and associated beginning of soil freeze-up at our large-scale water manipulation site near Barrow, Alaska (the Biocomplexity Experiment). We found that the autumn season CH4 emission is significant (accounting for 21–25% of the average growing season emission), and that this emission is mostly controlled by the fraction of inundated landscape, atmospheric turbulence, and the decline in unfrozen water during the period of soil freezing. Drainage decreased autumn CH4 emission by a factor of 2.4 compared to our flooded treatment. Flooding slowed the soil freezing process which has implications for extending elevated CH4 emissions longer into the winter season.

Publications Copernicus
Download
Citation