Methane oxidation in three Alberta soils: Influence of soil parameters andmethane flux rates

Current concern over the potentially negative impacts of climate change has brought attention to anthropogenic sources of methane, a primary greenhous e gas. Two such emission sources are methane leakage at heavy oil wells and sanitary landfills. At both of these sources, substantial quantities of me thane could potentially be oxidised by methanotrophic microbes living in so ils. Optimisation of this phenomenon may serve as an inexpensive technique for reducing methane emissions. Soil column and batch incubation experiment s were performed on a landfill loam, an agricultural loam and a sedge peat to gain a better quantitative understanding of the biological and physical processes limiting CH4 oxidation in soils that undergo the freeze-thaw cycl es associated with northern climates. Moisture content emerged as a critica l variable that can limit a soil's CH4 oxidation potential. For example, th e oxidation rate of the agricultural soil was seen to increase by an order of magnitude after increasing its moisture content from 6% to 10% of its dr y weight.