engleski

Comparison between the distribution of Cs-137 and K-40 in fir-tree (Abies alba)

Distribution of 137Cs and 40K among different parts of Abies alba was studied. The samples of needles grown on branch segments of different age, bark and tree rings of the trunk at the height of 8 m were taken. Very similar behaviour of 137Cs and 40K has been observed. The behaviour of 137Cs is more regular than that of 40K. In all samples the activities of 137Cs and 40K ascend in needles grown on younger branch segments and are the highest in needles from the tips of the branches. The comparison of distribution of 137Cs and 40K between needles and the bark was made as well as the comparison between tree rings and the bark. The ascending trend of both isotope activities toward younger samples was observed for needles and the bark. A regular interdependance between 137Cs activity in needles and the bark was also observed. 137Cs activities in tree rings are found to be uniform, with small variations. Compared to the tree rings, a great rise of 137Cs and 40K activities occurs in the bark. The rise is more emphasized for 137Cs than for 40K.

Cs-137; K-40; Abies alba; Gorski Kotar; needles; bark; tree rings

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