Soil surface CO<sub>2</sub> fluxes in a Norway spruce stand

Abstract

The measurements of soil CO<sub>2</sub> efflux in a Norway spruce (Picea abies [L.] Karst.) forest stand are reported for a 6-month period (from May 1<sup>st</sup> to October 26<sup>th</sup> 1999). Forest floor CO<sub>2</sub> 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<sub>2</sub> 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<sub>2</sub> efflux. On the basis of this relationship Q<sub>10</sub> values were calculated. The averaged value of Q<sub>10</sub> for the studied Norway spruce forest stand was 3.74.