137Cs allocation in forest ecosystems of Ukrainian Polissya

Abstract

It is determined that at present the largest share of the total activity of radionuclides in biogeocenosis is concentrated in soil: 86.27% — in wet pinewoods; and 98.88% — in wet sudubravas. It was determined that migration of radionuclides to woody plants in wet sudubravas is considerably less than that observed in wet bory. Thus, in 2012, the forest stand in wet sudubravas contained only 0.12% of 137Cs total activity in biogeocenosis. In wet pinewoods this ratio is much higher — 7.48% (by 62.3 times). The analysis of the distribution of the total activity of 137Cs in phytocenosis of the studied types of forest conditions showed that the highest radionuclide content is observed in the forest stand. 137Cs content in the plants lower layer is much lower. As it has been already mentioned, the value of the radionuclide specific activity in these plants is higher than in tree organs and parts of trees. But the mass of the tree layer is much bigger than the mass of any layer of plants located lower. Thus, the comparison of the mass of plants and the specific activity of the radionuclides in plants of each plant layer makes it possible to give preference to the first index in the distribution of the total activity in phytocenosis.