Abstract
Fresh leaf/needle, litter, surface soil, and stream bottom sand were monthly collected from Japanese cedar and deciduous broadleaf forests in the so-called “Satoyama” of Namie town in Fukushima Prefecture for one year from June 2012 to July 2013. The concentration of radioactive cesium (134Cs and 137Cs) was measured by a commercially available NaI(Tl) scintillation detector. The order of the concentration of the radioactive cesium was litter>surface soil>fresh leaf/needle>bottom sand, indicating that radioactive cesium had accumulated in the litter. Snow covering in the winter and snow melt in the spring did not affect the concentration of radioactive cesium in the litter both in the Japanese cedar and deciduous broadleaf forests. There was a high positive correlation between the concentration of radioactive cesium in the bottom sand at the upstream and the following month's concentration of radioactive cesium in bottom sand at the downstream, indicating that radioactive cesium was transported through the suspended sand at approximately 500 m per month in the studied small forest.
