Biogeochemistry

, Volume 16, Issue 3, pp 181–211

Oxidation of methane in boreal forest soils: a comparison of seven measures

  • Stephen C. Whalen
  • William S. Reeburgh
  • Valerie A. Barber
Article

DOI: 10.1007/BF00002818

Cite this article as:
Whalen, S.C., Reeburgh, W.S. & Barber, V.A. Biogeochemistry (1992) 16: 181. doi:10.1007/BF00002818

Abstract

Methane oxidation rates were measured in boreal forest soils using seven techniques that provide a range of information on soil CH4 oxidation. These include: (a) short-term static chamber experiments with a free-air (1.7 ppm CH4) headspace, (b) estimating CH4 oxidation rates from soil CH4 distributions and (c)222Rn-calibrated flux measurements, (d) day-long static chamber experiments with free-air and amended (+20 to 2000 PPM CH4) headspaces, (e) jar experiments on soil core sections using free-air and (f) amended (+500 ppm CH4) headspaces, and (g) jar experiments on core sections involving tracer additions of14CH4. Short-term unamended chamber measurements,222Rn-calibrated flux measurements, and soil CH4 distributions show independently that the soils are capable of oxidizing atmospheric CH4 at rates ranging to < 2 mg m−2 d−1. Jar experiments with free-air headspaces and soil CH4 profiles show that CH4 oxidation occurs to a soil depth of 60 cm and is maximum in the 10 to 20 cm zone. Jar experiments and chamber measurements with free-air headspaces show that CH4 oxidation occurs at low (< 0.9 ppm) thresholds. The14CH4-amended jar experiments show the distribution of end products of CH4 oxidation; 60% is transformed to CO2 and the remainder is incorporated in biomass. Chamber and jar experiments under amended atmospheres show that these soils have a high capacity for CH4 oxidation and indicate potential CH4 oxidation rates as high as 867 mg m−2 d−1. Methane oxidation in moist soils modulates CH4 emission and can serve as a negative feedback on atmospheric CH4 increases.

Key words

methane oxidationmethane budgetboreal forest

Copyright information

© Kluwer Academic Publishers 1992

Authors and Affiliations

  • Stephen C. Whalen
    • 1
  • William S. Reeburgh
    • 1
  • Valerie A. Barber
    • 1
  1. 1.Institute of Marine Science, University of AlaskaFairbanks