Mineralization of Organic Matter in Oil-Polluted and Remediated Oil-Polluted Soils in the Middle Taiga Zone of West Siberia under Laboratory Conditions

Mineralization rates of soil organic matter (SOM) decomposition in nonremediated and remediated oil-polluted soils and background soils from the main types of West Siberian middle-taiga ecosystems have been measured in laboratory experiments. The rates of SOM mineralization were measured by alkali absorption of CO 2 released from wet soil samples at 20°C (basal respiration). Taking into account the linear character of the cumulative curves of CO 2 release, the rates of SOM mineralization were estimated using the mineralization index K 1 , equal to the annual amount of CO 2 released per 1 g dry soil. The K 1 values varied from 0.123 to 1.578 mg CO 2 /g/day. The highest value was recorded in the background forest soil, while the lowest value in the oil-polluted peat soil with extremely high oil content (544 g/kg). The K 1 values were negatively correlated with oil content ( K = –0.57). The SOM mineralization rate in remediated oil-polluted peat soils varied from 0.31 to 0.85 mg CO 2 /g/day.