Comparing ¹³⁷Cs concentrations between coppices and planted saplings of deciduous broad-leaved trees in Fukushima

To restart shiitake mushroom bed log production, this study compared the ¹³⁷Cs radioactive concentrations between coppices and planted saplings of three deciduous broad-leaved tree species in a forest stand that was regenerated after the Fukushima Daiichi Nuclear Power Plant accident. Currently growing parts of shoots (current-year shoots) were collected from three tree species of konara (Quercus serrata) in three sites of forest stands, kuri (Castanea crenata) in five sites, and yamazakura (Cerasus jamasakura) in five sites from December 2016 to March 2017 in Miyakoji region, Tamura city, Fukushima. Konara and kuri showed statistically significant differences between coppices and planted saplings in one of three sites and four of five sites, respectively, whereas yamazakura did not show any difference. The ¹³⁷Cs concentration ratios of planted saplings and coppices in the sites ranged from 0.38 to 1.3 for konara, 0.37 to 1.6 for kuri, and 0.53 to 1.5 for yamazakura. Large variations in ¹³⁷Cs radioactive concentrations among coppices and planted saplings even in a single site obscured the differences between coppices and planted saplings. (author)