Methane oxidation rates were measured in boreal forest soils using seven techniques that provide a range of information on soil CH
4 oxidation. These include: (a) short-term static chamber experiments with a free-air (1.7 ppm CH
4) headspace, (b) estimating CH
4 oxidation rates from soil CH
4 distributions and (c)
222Rn-calibrated flux measurements, (d) day-long static chamber experiments with free-air and amended (+20 to 2000 PPM CH
4) headspaces, (e) jar experiments on soil core sections using free-air and (f) amended (+500 ppm CH
4) headspaces, and (g) jar experiments on core sections involving tracer additions of
14CH
4. Short-term unamended chamber measurements,
222Rn-calibrated flux measurements, and soil CH
4 distributions show independently that the soils are capable of oxidizing atmospheric CH
4 at rates ranging to < 2="" mg="">
–2 d
–1. Jar experiments with free-air headspaces and soil CH
4 profiles show that CH
4 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 CH
4 oxidation occurs at low (< 0.9="" ppm)="" thresholds.="">
14CH
4-amended jar experiments show the distribution of end products of CH
4 oxidation; 60% is transformed to CO
2 and the remainder is incorporated in biomass. Chamber and jar experiments under amended atmospheres show that these soils have a high capacity for CH
4 oxidation and indicate potential CH
4 oxidation rates as high as 867 mg m
–2 d
–1. Methane oxidation in moist soils modulates CH
4 emission and can serve as a negative feedback on atmospheric CH
4 increases.