Abstract
To measure spatial variation in soil CO2 efflux in a secondary beech forest in northern Japan, we took measurements five times over two years at 49 sampling points in a 35 m×35 m grid using a closed chamber method. There were relatively large variations in soil CO2 efflux in space over the study area (CV=15.8∼26.7). A tree index using tree position and size explained about 10% of spatial variation in soil CO2 efflux. The spatial variation in soil CO2 efflux was negatively correlated with an index of volumetric soil water content. Volumetric soil water content was negatively correlated to the distance and size of trees around the chambers. This suggests that stand structure altered volumetric soil water content and indirectly affected soil CO2 efflux.
