Житомирський державний технологічний університет, Житомир 2 Київська науково-дослідна станція Українського науково-дослідного інституту лісового господарства і агролісомеліорації ім. Г. М. Висоцького, Лютіж Київської області РОЗПОДІЛ 137 Cs У ДЕРНОВО-ПІДЗОЛИСТИХ ҐРУНТАХ ЛІСІВ ПОЛІССЯ УКРАЇНИ Проведено дослідження щодо розподілу 137 Cs у дерново-підзолистих ґрунтах лісів Полісся України в різних типах лісорослинних умов, з використанням показників питомої активності радіонукліда та щільності радіоактивного забруднення в шарах лісової підстилки та мінеральної частини ґрунту. На основі кількісної оцінки сучасного розподілу 137 Cs у ґрунті показано роль лісової підстилки в соснових насадженнях як геохімічного бар'єра на шляху міграції радіонукліда у ґрунті, установлено найбільшу щільність радіоактивного забруднення в гумусово-елювіальному горизонті. Ключові слова: радіонукліди, радіоактивне забруднення ґрунту, питома активність радіонукліда, лісові насадження, дерново-підзолисті ґрунти. 137 Сs DISTRIBUTION IN SOD-PODZOL FOREST SOIL OF UKRAINIAN POLISSIA 137 Cs distribution in sod-podzol forest soil of Ukrainian Polissia in different types of forest condition is studied. Rates of specific and total radionuclide's activity in the layers of forest floor and in the mineral part of soil are analyzed. According to the qualitative study of 137 Cs distribution in the soil of pine plantation the forest floor is considered to be the geochemical barrier for the migration of radionuclides into soil. The highest total radionuclide activity in humuseluvial horizont is observed.

The botanical composition of the European roe deer diet in the radioactively contaminated forest ecosystems of Zhytomirske Polesie of the Ukraine was investigated. Deer were caught monthly over a two–year period on three plots in forest habitats typical for Zhytomirske Polesie (fresh and moist mixed coniferous forests and mixed broadleaved forests). An analysis of the stomach contents of hunted deer showed that they consumed leafy as well as leafless stems, grasses, fruits and mushrooms depending on the season and availability of forest plants. Each season was characterized by one major dietary component. In the spring, the main component of the deer diet was the stems of woody plants. 44 species of vascular plants (3% of the natural flora of the region) were identified in the roe deer diet including 41 species of Magnoliophyta, of which 34 species of Magnoliopsida and 7 species of Liliopsida, 2 species of Polipodiophyta and one species of Pinophyta. Species such as aspen (Populus tremula), oak (Quercus robur), blackberry (Rubus nessensis) and bilberry (Vaccinium myrtillus) were consumed year-round.

The data on 137 Cs distribution in sod-podzol forest soils of Ukrainian Polissia contaminated by radionuclides after Chornobyl accident are presented. Researches were conducted on the permanent sample areas in wet bory and sugrudy in 2000 and in 2012 years. It is proved that 137 Cs migration from the forest litter to the soil mineral part occurred comparatively quickly. It can be explained by a thin layer and a high mineralization of the forest litter in wet sugrudy. Nevertheless, wet bory are characterized by more intensive radionuclide migration to the deeper layers of the soil mineral part. Such regularity can be explained by a small amount of humus and fine-dispersed particles as well as higher soil acidity in wet bory.

Radioactive contamination of the aboveground phytomass of marsh Labrador tea (Ledum palustre L.) in different periods after the Chernobyl accident was studied. Marsh Labrador tea is widely used in official and folk medicine. The studied species grows in over-moistened pine (less mixed) forests and open oligotrophic and mesotrophic marshes. It was found that in the first four years since the beginning of observations (1991), the magnitude of the specific activity of 137 Cs in above-ground vegetative phytomass of marsh Labrador tea, depending on a permanent sample area (PSA), decreased by 1.2-1.4 times. After 10 years, it decreased by 1.6-1.7 times, after 16 years by 1.9-2.1 times, after 21 years by 2.7-3.1 times, and after 27 years by 3.1-6.5 times. An increase in the magnitude of transitions factors was also observed on all PSA over time. Thus, the minimal increase within 1991-2018 was recorded in PSA 11-by 1.2 times and on PSA 13-by 1.4 times. The maximum decrease in the magnitude of transition coefficient was observed in PSA 16-by 2.7 times, in PSA 15-by 3.0 times, and in PSA 18-by 2.0 times. It was found that marsh Labrador tea belongs to the group of plants that are characterized by the high content of 137 Cs in the above-ground vegetative phytomass. Within the observation period (1991-2018), this content significantly exceeds the admissible levels of radionuclide content in plant medicinal raw materials that are used for manufacturing medical preparations. In the PSA with maximum magnitudes of soil contamination density (400.5±50.73 kBk•m-2) this excess made up 158.4 times in 1991, and 33.7 times (166.9±23.56 kBk•m-2) in 2018. For 27 years of observations, there has been a decrease in the density of radioactive soil contamination by 2.1-2.7 times, which is due to radionuclide decomposition, its vertical migration in the soil, and towards the components of forest ecosystems

Установлено, що продовжується інтенсивне надходження 137 Cs до надземної частини фітомаси та ягід чорниці. Дослідження проведено на дерново-середньопідзолистих, піщаних ґрунтах вологих суборів. Коефіцієнти переходу 137 Cs (м 2 кг -1 10 -3 ) в надземну частину чорниці (17 -53) значно більші, ніж в ягоди (4 -8). Виявлено зниження рівнів радіоактивного забруднення 137 Cs надземної фітомаси та ягід чорниці за період спостережень. Протягом 1991 -2016 рр. питома активність 137 Cs в ягодах чорниці знизилася у 3,7 -8,3 раза, у надземній частині -у 8,2 -19,2 раза. У верхньому 0 -10-см шарі мінеральної частини ґрунту вологих суборів міститься 69,9 % від сумарної активності радіонукліда в ґрунті. Найбільша величина цього показника встановлена для 0 -2-см шару мінеральної частини ґрунту -28,4 ± 2,0 %. Найбільша питома активність 137 Cs встановлена для розкладеної частини лісової підстилки та верхнього 0 -2-см шару гумусово-елювіального горизонту.

Oligotrophic and mesotrophic bogs are common ecosystems in Polissia of Ukraine. After the Chernobyl accident, these ecosystems were contaminated with radionuclides. A common berry plant in these bogs is the cranberry, which is widely used in food industry. The aim of research is to establish dynamics of migration of 137Cs in cranberries during the last 30 years. The obtained results of monitoring studies are necessary for prognosis of radioactive contamination of cranberry. Investigation was conducted on stationary experimental plots (SEP) in Zhytomyr Polissia. 137Cs specific activity was measured on spectrum analyzers with scintillation and semiconductor detectors. Obtained results testify about intensive 137Cs migration on sphagnum bogs of Polissia of Ukraine. Results of investigation conducted after 34 years of Chornobyl accident showed low values of 137Cs specific activity in cranberry (Vaccinium oxycoccus L.) on all stationary experimental plots. This index in 2020 in fresh berries hesitate from 871±82.6 to 286±16.9 Bq/kg (at the permissible level 500 Bq/kg), and in dry shoots – from 1492 (SEP 15) to 6197 Bq/kg (SEP 12). It was found that in the first period (1991-1996) rather significant decreasing of 137Cs specific activity was observed in fresh berries of cranberry – from 3.8 times on SEP 11 to 2.2 times on SEP 12. In the next period (1996-2002) this decreasing was in the limits 1.4-2.9 times that is lower than in previous one. In the following period decreasing of 137Cs specific activity in berries was significantly lower. Revealed regularities of decreasing of 137Cs specific activity in berries during 1991-2020 also confirmed by decreasing of this index in the plant shoots. Total decreasing of this index in dry shoots on the whole period of investigation was: on SEP 11 – from 94590±4236 to 6099±366 Bq/kg (15.5 times), on SEP 12 – from 31800±2325 to 6197±242 Bq/kg (5.1 times), on SEP 15 – from 12120±898 to 1492±112 Bq/kg (8.1 times), on SEP 18 – from 14732±1126 to 1854±112 Bq/kg (7.9 times). Сontinuation of monitoring on stationary experimental plots will allow to predict levels of radioactive contamination of cranberry on the base of mathematical modeling

Cs DISTRIBUTION IN THE WOOD OF SCOTS PINE RADIAL GROWTH IN THE FORESTS OF UKRAINIAN POLISSIAThis research was conducted in regards to the distribution of 137 Cs in the radial growth of pine forests within the humid pine forests of the Polissia, Ukraine. To set the value patterns we used radionuclide specific activity of 5-year rings that were formed before and after the accident. Based on the quantitative assessment of the modern distribution of 137 Cs in pine wood it showed much higher levels of radionuclide in the peripheral annual rings. This analysis was marked by very significant values that were found in the forests formed after the accident at Chernobyl. The latter can be explained as the movement of radionuclide from the wood formed after the accident and radioactive contamination of forest ecosystems due to global fallout.

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