Field measurement of heterotrophic respiration of root litter using a small chamber system

Abstract

In order to estimate the heterotrophic respiration of fine dead root (Rhr.), we tested a new method of direct measurement of dead roots buried in the L-layer of forest soil using a small chamber system. CO 2 efflux from the dead roots ranged 83.3 - 577.3 mg CO2 kg-1h-1 and was inferred to be from the decomposition of the dead roots. The CO2 efflux showed seasonal change and increased exponentially with increasing soil temperature. In addition, CO2 efflux increased with decreasing mean root diameter, and the relationship could be described by a power function. Our results suggested that seasonal change and decomposition of very fine roots morphology need to be considered in estimating CO2 efflux from fine root litter in forest soils.