Development of Finnish peatland area and carbon storage 1950–2000

This study summarizes the present knowledge of Finnish peatland areas and carbon (C) storage in peat from 1950 to 2000.In 1950, approximately 8.8 million ha of the Finnish peatland area was still undisturbed and 1.4 million ha drained.In 2000, almost 55% (5.7 million ha) of the peatland area in Finland was drained for forestry, 38.4% (4.0 million ha) was undrained, 0.8% (85 000 ha) was in agriculture, 0.6% (60 000 ha) was under water reservoirs, 0.3% (35 000 ha) was under roads and 0.6% was in peat harvesting or had been removed from the harvesting business (63 000 ha).The change in mire area is considered relatively reliable, whereas the net changes in the actual C sequestration and the actual C storage change from 1950 to 2000 involves much more uncertainty.In 2000, the total C storage of Finnish peatland ecosystems was estimated at 5960 Tg, which includes 5304 Tg as peat.Since 1950, the C sequestration of undrained and drained peatlands (peat, plant biomass) basically compensated for the anthropogenic losses.The most important forms of anthropogenic C losses have occurred from agricultural peat soils, water reservoirs, harvested peat and DOC output from forestry drained peatlands.From 1950 to 2000, the total C storage of Finnish peatlands, which includes peat and living plant biomass, was estimated to increased by 52 Tg because the intensive peatland drainage significantly increased the total C storage of vegetation.However, the actual C storage in peat decreased by about 73 Tg.The welldefined changes include the decrease of mire diversity because of forestry drainage.