%0 Research Notes %T Past and present carbon accumulation in undisturbed boreal and subarctic mires: a review %A Turunen, Jukka %D 2003 %J Suo - Mires and peat %V 54 %N 1 %U http://suo.fi/article/9825 %X This review integrates the results from several recent studies on carbon (C) accumulation in undisturbed boreal and subarctic mire ecosystems in Finland, Sweden, Russia, Canada, and USA. Generally, a large variation in the average long-term apparent rate of carbon accumulation (LORCA) has been found among mires based on the mire type, age and geographical location. The differences in LORCA between the raised bog region and the aapa mire regions were found to be significant. The updated LORCA for undrained boreal and subarctic mire regions has been estimated at 13–20 g C m–2 a–1 throughout the Holocene, which is clearly lower than previous estimates for these northern mire regions. The age of the peat column is an important predictor of C accumulation and has to be taken into account when comparing results. The results indicate a rapid mire expansion in southern Finland from ca. 10 500 to 8500 cal. year BP, from 5000 to 3000 cal. year BP and around 2000 cal. year BP. In northern Finland the extensive mire expansion occurred from ca. 10500 to 8000 cal. year BP. The recent apparent rate of C accumulation (RERCA) in boreal and subarctic mire regions over the past 100 to 200 years ranges from 30 to 120 g C m-2 a-1. The future C balance scheme of mires is also briefly discussed. Key words: carbon accumulation, bogs, fens, boreal region, subarctic region, Holocene, climate change