Abstract
The purpose of this study was to clarify the changes in the concentration and amount of radiocesium in decomposing litters in Satoyama consisting of deciduous broad-leaved forest where radionuclides released from the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) were deposited. The concentration and amount of radiocesium in decomposing litters before and after the FDNPP accident (March 2011) were compared. The concentration of radiocesium in leaf litter was 2.3-14.6 Bq/kg from March to November in 2009. The concentration of radiocesium in leaf litter significantly increased after the autumn of 2012. The amount of radiocesium in leaf litter increased despite a decrease in dry mass with decomposition relative to the beginning of the study period. It suggested that increases in the concentration and amount of radiocesium in decomposing litters might be attributed to the incorporation of radiocesium via microbial absorption in the soil surface, and concentrated with the weight loss.
