Changes in carbon pools of peatland and forests in northwestern Russia during the Holocene

Estimates of changes in carbon pools of vegetation and soils during the Holocene are contradictory due in part to incomplete information. The peat carbon pool has increased in northwestern Russia due to paludification but the intensity of paludification and carbon accumulation rate was not constant during the Holocene. We estimate that the average long-term accumulation rate in peatlands of Russia was 44•109 kg C/yr or 28.6•10−3 kg C/m2 yr. According to our model calculations, the maximum rate of peat accumulation in northwestern Russia was reached in the Boreal (early Holocene) (34.5•10−3 kg C/m2 yr) and the late Atlantic time (mid Holocene) (about 30•10−3 kg C/m2 yr). The rate decreased during the Subboreal time to 17•10−3 kg C/m2 yr. Modern rates of carbon accumulation in some types of peatlands of Russia, calculated by peat-growth model, range from 20•10−3 kg C/m2 yr to 100•10−3 kg C/m2 yr. The forest composition of northwestern Russia also changed during the Holocene, but the changes in carbon pool of phytomass did not exceed 5% from the mid-Holocene to the present