Tormod Lien , Pertti Martikainen, Hannu Nykänen, Lars Bakken

Methane oxidation and methane fluxes in two drained peat soils

Lien T., Martikainen P., Nykänen H., Bakken L. Methane oxidation and methane fluxes in two drained peat soils.

Tiivistelmä

Methane production and consumption in drained minerotrophic and ombrotrophic peat was investigated using a combination of field measurement and laboratory incubations. In the field, methane fluxes were measured at intervals over a seven (minerotrophic) and ten (ombrotrophic) month period together with measurements of methane concentrations and temperature at various depths. In the laboratory, aerobic incubations of drained peat samples from various depths were conducted over a range of temperatures to determine rates of potential methane oxidation. The maximum potential methane oxidation rate occurred at a depth close to that of the water table. The oxidation rate was much higher in the ombrotrophic peat than in the minerotrophic peat. However, field measured methane fluxes were lower in the minerotrophic peat. This is attributed to a relatively low water table. Methane oxidation increased over the temperature range 2 to 30°C and decreased at temperatures >34°C. Methane production in the aerobic incubation experiment was measured by inhibition of methane oxidation with dimethyl ether. Production rates were only 1-7% of net oxidation rates. Thus, the measured net rates of methane absorption in aerobic incubations largely reflect gross oxidation rates. Keywords: Bog, fen, temperature, water level

Avainsanat
bog; fen; temperature; water level

Vastaanotettu 31.10.2017 Julkaistu 1.1.1992

Katselukerrat 1825

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