Greenhouse Impact of a Mire after Drainage for Forestry

Greenhouse gases absorb infrared radiation and thus change the Earth’s radiation energy transfer to space. In spite of this amount of peatland drainage activity, little comprehensive data exists about the drainage effects on the carbon balance and possible greenhouse impact of these ecosystems. Peatland drainage for forestry in the boreal and temperate zones has been extensive – about 14 million ha of peatland and wetlands. Drainage initiates a succession, where species composition in the ecosystem gradually changes toward forest vegetation. This chapter describes the greenhouse impact arising from the drainage for forestry of a peatland site type of median nutrient level in Finland. The long-term effect of drainage on the CO₂ balance of the mire was estimated indirectly by measuring the change in the carbon stores of the mire after drainage. The amount of carbon stored in the tree stand was calculated for a time period between 50 years before and 300 years after the drainage.