Carbon accumulation in a raised bog : Simulation on the basis of laboratory measurements of CO2 exchange.

Laboratory measurements on the CO2 exchange and data on actual field temperatures and irradiation were used to compute (by simulation) an annual carbon budget for the Empetrum nigrum/Sphagnum fuscum community. A net fixation of 160 g CO2 m-2 was predicted for the growing season. This was already the figure at the beginning of July, after which no significant change occured. For one day in June (when CO2 exchange was most intense), estimates of c. 10 and 7 g CO2 m-2 for total photosynthesis and total respiration were derived, respectively. The annual net result is in accordance with earlier estimates of production and carbon accumulation in similar ecosystems, thereby partly validating the model. Radical changes in the annual peat production are to be expected, if the mean temperature changes even one or two Celsius degrees; an increase of 2° C resulted in an equilibrium in the carbon flow between bog and atmosphere (i.e. no net change in the carbon content of the bog).