Land-Atmosphere Exchange of CO2, Water and Energy at a

and sub-arctic peatlands cover a small part of the global land area (only ca 3%) but have stored considerable amounts of carbon during Holocene. The carbon stored is equivalent to ~ 20-30 % of the global soil carbon pool and ~ 40-60 % of the carbon currently held in the atmosphere as CO2. Due to the enormous amounts of carbon available in the peat, great interest has been paid to whether the carbon will remain in the peatlands, or migrate to the atmosphere. The current fluxes of carbon between these ecosystems and the atmosphere are therefore considered to be important in global carbon budgets, and may be even more important in the future, if the exchange rates change in response to anticipated climatic changes. Five years of continuous Eddy Covariance measurements on an acid, oligotrophic, minerogenic, mixed mire, Degerö Stormyr, has shown that the mire ecosystem was a stable sink for CO2, with an uptake of 54 ± 6 gCO2-Cm-2y-1 (±SD). Also when considering carbon effluxes such as by CH4-C or carbon in the runoff water, the mire still remains as a stable sink of 27 ± 6 gCm-2yr-1 (±SD). A positive water balance is a prerequisite for the development and maintenanc