Methane oxidation in a peatland core

We made an experiment on a 30 cm. diameter core of Sphagnum-dominated veget ation and peat to estimate the parameters controlling methane oxidation dur ing movement to the ambient air: 13 CH4 was added at the water table, and e xcess 13 CO2 appeared in the gas space above the core. At 20 degreesC in ot herwise undisturbed conditions, similar to 22% of CH4 was oxidized to CO2 d uring passage up through the overlying 10-cm thick unsaturated peat and pla nts. We simulated the experiment, with seven parameters: transfer coefficie nts in water, in the gas phase, and through the container wall; the rate of CH4 and Of CO2 generation; and the two parameters of a hyperbolic relation between CH4 concentration and the rate of CH4 oxidation. We optimized thes e parameters to fit the experimental results, and then were able to general ize to any temperature (0 degrees -25 degreesC) and any depth (0-55 cm) of water table. Changing temperature has important effects on the proportion o f CH4 oxidized.