Soil surface CO 2 fluxes in a Norway spruce stand

The measurements of soil CO 2 efflux in a Norway spruce (Picea abies (L.) Karst.) forest stand are reported for a 6-month period (from May 1 st to October 26 th 1999). Forest floor CO 2 efflux was measured at four positions using a portable infra- red gas analyser (LI-COR), operating as a closed dynamic system and connected to a portable soil chamber. Soil CO 2 efflux was measured 3-4 times per month. Soil temperature at a depth of 5 cm was recorded during the whole period with an interval of ten minutes. An exponential regression was used to describe the relationship between soil temperature and soil CO 2 efflux. On the basis of this relationship Q 10 values were calculated. The averaged value of Q 10 for the studied Norway spruce forest stand was 3.74.