Accumulation of 137Cs by fungal mycelium in forest ecosystems of Ukraine

During 1996-1998, 16 fruit bodies of different species and 204 soil samples down to 10 cm in the close vicinity of the fruit body sites were collected in a coniferous forest in the Ovruch region of Ukraine. The soil samples were sliced into I or 2 cm layers and the fungal mycelium was prepared from each of the layers. The Cs-137 activity concentration was determined in both soil and-mycelium. The, mean weight of fungal mycelium was 13.8 mg g(-1) of soil in the upper, 4 cm and 7.3 mg g(-1) when measured for the upper 10 cm. At the sites of Paxillus involutus and Sarcodon imbricatus; the mycelium was rather homogeneously distributed in the upper 10 cm and at sites of Xerocomus subtomentosus and Cantharellus cibarius, the mycelium was distributed mostly in the upper layers. The highest Cs-137 activity concentrations were found in the upper layers of the soil profile. The Cs-137 activity concentrations were usually higher in the fruit bodies compared with the mycelium, with ratios ranging from 0.1 to 66 and a mean of 9.9. The percentage of the total inventory of Cs-137 in the soil found in the fungal mycelium ranged from 0.1 to 50%,, with a mean value of 15%. (C) 2002 Elsevier Science Ltd. All rights reserved.