Carbon storage in the peatlands of Mecklenburg-Western Pomerania, north-east Germany

Peatlands are becoming increasingly important in the context of climate change because they store large amounts of carbon, but information regarding the exact amount of carbon is scarce. In their natural state (as mires), they sequester and store organic carbon (Corg), but they emit CO2 when drained. In calculating Corg storage, little attention has been paid to the fact that many peatlands have been intensively drained and used for more than 200 years, such that their soil characteristics have changed. Recent estimates of peatland carbon storage are based on simplified data for peat thickness, bulk density and Corg content. This paper offers an alternative method for estimating the amount of carbon stored which takes into account peatland type and secondary soil development. Peatlands that originated as different hydrogenetic mire types (HGMTs) store different amounts of carbon due to stratigraphical differences. It is estimated that 430 Mt of Corg is stored in peatlands belonging to the three dominant HGMTs in Mecklenburg-Western Pomerania (north-east Germany), and that percolation-mire peatlands store up to ten times more Corg than water-rise-mire peatlands. It is also demonstrated that gyttja soils make a significant contribution to Corg storage in terrestrialisation-mire peatlands; thus, after peats, these are the next most important soils for Corg stocks.