Âderna Fìzika ta Energetika (Mar 2019)
137Cs and 40K in the needles and branches of scotch pine (Pinus sylvestris L.) on the territory of Chornobyl Exclusion Zone
Abstract
Changes of the 137Cs and 40K content during a year in the plants of forest ecosystems were investigated on the territory of the "Paryshev" sampling area (the Chornobyl NPP exclusion zone). One- and two-year-old needles and branches of P. sylvestris were used as objects of study. Samples were se-lected at intervals of 1 time every two weeks during 2014 and 2015. As a result of the research, it was found that the magnitude of the specific activity of 137Cs and 40K in the needles and branches of P. sylvestris is not constant, but leaped during the year. It has been suggested that fluctuations in the concentrations of activity of these radionuclides in the studied organs of P. sylvestris are associated with their circulation in the chain "soil - fungus-symbiotroph - plant". The correlation coefficients R within 0.5 - 0.68 indicate the existence of direct and moderate relationship between fluctuations in the concentration of 40K and 137Cs activity in the needles and branches of P. sylvestris throughout the year. Probably, the mechanisms of absorption and escape of these radionuclides in P. sylvestris are similar. The content of 40K in the researched organs is higher than the content of 137Cs. It can be connected to the ability of the mycorrhiza to hold radiocaesium (to be a barrier) and to the selective accumulation of potassium by the plant.
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