Morphological defects in native Japanese fir trees around the Fukushima Daiichi Nuclear Power Plant.

Yoshito Watanabe,Yoshihisa Kubota,Isao Kawaguchi,Kouichi Maruyama,Junko Hoshino,Vasyl I Yoschenko,San’Ei Ichikawa,Masahide Kubota,Satoshi Yoshida,Shoichi Fuma

doi:10.1038/srep13232

Abstract

After the accident at the Fukushima Daiichi Nuclear Power Plant (F1NPP) in March 2011, much attention has been paid to the biological consequences of the released radionuclides into the surrounding area. We investigated the morphological changes in Japanese fir, a Japanese endemic native conifer, at locations near the F1NPP. Japanese fir populations near the F1NPP showed a significantly increased number of morphological defects, involving deletions of leader shoots of the main axis, compared to a control population far from the F1NPP. The frequency of the defects corresponded to the radioactive contamination levels of the observation sites. A significant increase in deletions of the leader shoots became apparent in those that elongated after the spring of 2012, a year after the accident. These results suggest possibility that the contamination by radionuclides contributed to the morphological defects in Japanese fir trees in the area near the F1NPP.

Highlights

Coniferous tree species are grown in the area highly radioactive contaminated by the F1NPP accident, where Japanese fir (Abies firma) is one of the most common naturally grown species
The overall frequency of the morphological defects of the main axis varied among observation sites, S1, S2, and S3, but it was significantly higher in each site compared to the control, S4
Significant increases in the morphological defects were shown in Japanese fir populations growing in areas near the F1NPP

Summary

Introduction

Coniferous tree species are grown in the area highly radioactive contaminated by the F1NPP accident, where Japanese fir (Abies firma) is one of the most common naturally grown species. Coniferous species, young-tree populations of Japanese fir are abundant, because this species has the characteristic ability to sprout even on the shaded forest floor. The short height of young trees enables the easy observation of morphological changes in the whole tree. The regular annual branching of Japanese fir trees enables determination of the year that any morphological changes occurred through a number of past years (Fig. 1). We examined the morphological changes in annual leader shoots for the past five years within the highly contaminated area around the F1NPP13. Fir trees were examined in a slightly contaminated control site (S4), southwest of the F1NPP

Methods

Results

Conclusion