Radiocesium in Stem, Branch and Leaf of Cryptomeria japonica and Pinus densiflora Trees:

Cases of Forests in Minamisoma in 2012 and 2013

Abstract

Radiocesium distribution in trees of forests in Mimamisoma, Fukushima, was studied in 2012 and 2013 after the Fukushima Daiichi Nuclear Power Plant Accident. Foliage and bark contained the most of radiocesium in each tree. A relatively high concentration (>1 Bq/g) of radiocesium was detected in the xylem of Cryptomeria stems. At higher parts of the stems, the heartwood contained more radiocesium than the sapwood. As a stem that had been felled just before the accidental deposition also contained radiocesium in its xylem, we de- duced that the radiocesium in xylem was not transferred through the root system but likely translocated from foliage.