THE CONTENT OF 137Cs IN THE ABOVEGROUND PART OF PLANTS IN FRESH PINE WOODS OF UKRAINIAN POLISSIA

Abstract

The radioactive contamination of the aboveground part of plants of pine plantations with ¹³⁷Cs under the
conditions of fresh pine woods of Ukrainian Polissia was investigated. The research was conducted on sample
plots established in the Narodychy forestry, where six samples of the aboveground parts of plant species
and the corresponding samples of soil were selected. Before measuring ¹³⁷Cs specific activity all samples
were dried to air-dry state and homogenized. The classical method of comparative ecology was taken as a
basis of the researches. The average value of soil radioactive contamination within the permanent sample
plots varied from 106 to 380 kBq/m2 (the variation coefficient was 29 %). Significant fluctuations of the specific
activity values of ¹³⁷Cs for all the investigated species were found. The maximal content of ¹³⁷Cs was
found in the aboveground part of Melampyrum pretense (104291 Bq/kg) and the minimal one – in Peucedanum
oreoselinum (L.) Moench (217 Bq/kg). While comparing the content of ¹³⁷Cs in the aboveground part of
the Poaceae family, it was found that the Koeleria glauca (Spreng.) DC was characterized by considerably
higher values of the investigated index than the Festuca ovina L. In the process of analyzing ¹³⁷Cs concentration
in the aboveground part of Vaccinium vitis-idaea L. and Calluna vulgaris (L.) Hill, the fluctuation of the
investigated parameter was found within each sample plot. Intensity indices of ¹³⁷Cs incoming in the aboveground
part of plants of fresh pine woods for all the researched species varied considerably: the accumulation
coefficient varied from 0.1 to 53.9, the transition coefficient – from 0.8 to 594 m2·kg-1·10-3. According to
the results of a single-factor analysis of variance, the aboveground parts of plants were classified into 5
groups as to their ability to accumulate ¹³⁷Cs. By the accumulation intensity of ¹³⁷Cs in fresh pine woods
plants can be represented in the following order: Melampyrum pratense > Calluna vulgaris (L.) Hill. > Vaccinium
vitis-idaea L. > Koeleria glauca (Spreng.) DC > Festuca ovina L. > Peucedanum oreoselinum (L.)
Moench. The concentration values of ¹³⁷Cs in the studied species have a close linear relation with the value
of the density of soil radioactive contamination.