Radiocesium Translocations in Bamboos

In this chapter, the study (Umemura M, Kanasashi T, Sugiura Y, Takenaka C, J Jpn For Soc 97:44–50, 2015) on the distribution of radiocesium (137Cs) in a Moso bamboo (Phyllostachys pubescens) forest in Fukushima Prefecture after the accident of Fukushima Daiichi Nuclear Power Plant (FDNPP) is introduced. We investigated the 137Cs contamination levels in aboveground organs of the bamboos which sprouted before and after the accident and belowground organs, visually and quantitatively. From the analysis on the aboveground organs sampled in 2012, the highest 137Cs concentrations were detected in the node parts of both the culms and branches of the bamboos sprouted before 2011 due to the direct fallout of radioactive substances. This fact indicates a long-lasting contamination without leaching of 137Cs by rain which strongly adhered on the surface of the mature bamboos. From similar 137Cs concentrations in each organ among the different-aged bamboos, it was supposed that 137Cs diffused from the bamboos sprouted before 2011 to those sprouted in 2011 just after the accident and also that the root absorption of 137Cs might affect the contamination in the bamboos sprouted in 2011. However, we did not find the evidence of root absorption in 2014 from the results of 137Cs distribution in the root. These findings suggested that 137Cs absorbed just after the accident has been diffusing throughout the bamboo forest via the rhizome system.