Estimation of radiocesium uptake from forest floor in Japanese cedar and Japanese konara oak stands of the Abukuma Mountains, Fukushima

Niizato, Tadafumi; Sasaki, Yoshito; Ito, Satomi; Watanabe, Takayoshi; Amamiya, Hiroki*

no journal, , 

An understanding of long-term environmental dynamics of radiocesium in forested area, which is released by the TEPCO's Fukushima Dai-ichi Nuclear Power Plant accident, is a key issue for predicting the future forest products radioactivity. In this paper we present the radiocesium uptake from forest floor in an evergreen Japanese cedar and a deciduous Japanese konara oak forests of the Abukuma Mountains, Fukushima. An investigation was conducted from 2015 to 2019. According to the International Biological Programme, IBP, annual radiocesium uptake from forest floor to the stand is estimated as follows; annual radiocesium increment associated with tree growth plus annual loss through litterfall, stemflow, and throughfall. The rate of annual radiocesium uptake to the total inventory of the stands associated with tree growth were estimated to be 0.1 and 0.06% in Japanese konara oak and Japanese cedar stands, respectively. The sum of radiocesium uptake including the loss of radiocesium amount by litterfall, stemflow, and throughfall were 1.37 and 3.13% in the konara oak and the cedar stands, respectively. The rate of radiocesium uptake estimated are lower than the elemental uptake in deciduous tree stands near Kyoto by IBP. This indicate that the radiocesium uptake by the konara oak and the cedar stands is limited and no significant increase in radiocesium concentration of tree tissues is expected in the study stands.