FEATURES ACCUMULATION OF CESIUM-137 BY MOSS LAYER OF UKRAINIAN POLISSIA

The radioactive contamination of the Dicranum polysetum Sw. and Pleurozium schreberi in fresh pine forests of Ukrainian Polissia at different density of radioactive contamination of soil is investigated. It was found that the density of radioactive soil contamination in all sample plots varied in wide ranges from 3 to 361 kBq/m² . It was established that btyidea (green) mosses are characterized by a high content of ¹³⁷Cs even with insignificant values of the density of radioactive contamination of the soil. In Malin forestry, at low values of soil pollution density ¹³⁷Сs, the maximum values of the specific activity of ¹³⁷Cs for Dicranum polysetum Sw. were 345 ± 12 Bq/kg, and for Pleurozium schreberi – 300 ± 14 Bq/kg. In Narodychi forestry at significantly higher density of soil radioactive contamination (up to 100 times) these values were 16861 ± 386 Bq/kg and 9327 ± 214 Bq/kg, respectively. It has been determined that the radioactive contamination of the vergopulo moss (Dicranum polysetum Sw.) significantly exceeds the contamination of the bokoblin moss (Pleurozium schreber). Within the Narodychi forestry was observed by significantly higher levels the concentration of ¹³⁷Cs in Dicranum polysetum Sw. relatively the Pleurozium schreber was 1.7 times, in Malin forestry up to 1.6 times. General regularity in the distribution of radioactive contamination by moss fractions has been noted. The moss fractions can be placed in the following ascending order: combings > live part > dead part by the magnitude of radioactive contamination. The concentration of ¹³⁷Cs in the moss layer has a close (r = 0.83-0.85) linear relationship with the density of soil radioactive contamination