CO2 exchange in the Empetrum nigrum-Sphagnum fuscum community.

The CO2 exchange of the Empetrum nigrum-Sphagnum fuscum community of a raised bog was studied in the laboratory at different temperature (from 5 to 30° C) and irradiance (up to 128 W m-2) combinations during one growing season. The total CO2 exchange was divided into three components, namely those due to Empetrum nigrum, Sphagnum fuscum, and peat, respectively. At the optimum temperature (10 to 15° C) the maximum net CO2 exchange of Empetrum nigrum was c. 200 and that of Sphagnum fuscum c. 250 mg CO2 m-2h-1. The total respiration in peat increased exponentially from 50 to 350 mg CO2 m-2h-1 with increasing temperature from 5 to 30° C. About 40% of the CO2 fixed by the community in optimal temperature and irradiation conditions was released immediately.