Journal cover Journal topic
Biogeosciences An interactive open-access journal of the European Geosciences Union
Biogeosciences, 9, 5291-5301, 2012
© Author(s) 2012. This work is distributed under
the Creative Commons Attribution 3.0 License.
Research article
20 Dec 2012
Non-microbial methane formation in oxic soils
A. Jugold1, F. Althoff1, M. Hurkuck1,2, M. Greule1, K. Lenhart1, J. Lelieveld1, and F. Keppler1 1Max-Planck-Institute for Chemistry, Hahn-Meitner-Weg 1, 55128 Mainz, Germany
2Johann Heinrich von Thünen-Institute, Institute of Agricultural Climate Research, Bundesallee 50, 38116 Braunschweig, Germany
Abstract. Methane plays an important role as a radiatively and chemically active gas in our atmosphere. Until recently, sources of atmospheric methane in the biosphere have been attributed to strictly anaerobic microbial processes during degradation of organic matter. However, a large fraction of methane produced in the anoxic soil layers does not reach the atmosphere due to methanotrophic consumption in the overlaying oxic soil. Although methane fluxes from aerobic soils have been observed, an alternative source other than methanogenesis has not been identified thus far.

Here we provide evidence for non-microbial methane formation in soils under oxic conditions. We found that soils release methane upon heating and other environmental factors like ultraviolet irradiation, and drying-rewetting cycles. We suggest that chemical formation of methane during degradation of soil organic matter may represent the missing soil source that is needed to fully understand the methane cycle in aerobic soils. Although the emission fluxes are relatively low when compared to those from wetlands, they may be important in warm and wet regions subjected to ultraviolet radiation. We suggest that this methane source is highly sensitive to global change.

Citation: Jugold, A., Althoff, F., Hurkuck, M., Greule, M., Lenhart, K., Lelieveld, J., and Keppler, F.: Non-microbial methane formation in oxic soils, Biogeosciences, 9, 5291-5301,, 2012.
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