The relations between Cs-137, unsupported Pb-210 and chemical properties in forest soil

In order to research the relations between the activities of radionuclides and soil chemical properties, we measured Cs-137, unsupported Pb-210 activities and some soil chemical properties, and compared. The study site, Otyouzu basin, is mainly covered with Hinoki (Japanese cypress) stands. The 16 samples was sampled at 10m intervals with a core sampler. The concentration of Cs-137, unsupported Pb-210 in soils, and other chemical properties of soil are measured and compared each other. As chemical properties of soil, ECEC, Carbon contents (C), Fed, Feo, Fet, clay contents (clay), pH(H2O), P-t, P-org, P-ava were measured. And, from these datum, Feo/Fed, (Fed-Feo)/Fet, P-ava/P-t, C/P-org were calculated. The Correlation Coefficients (C.C.) between both radionuclide and carbon contents is relatively high. Although there were no correlations between contents of each from of phosphorus, C.C. between both radionuclide activities and C/P-org, P-ava/P-t were relatively high. It may be dew to the uneven distributions of some elements or nutrients in forest soil. So it may suggest that the concentration of Cs-137 and unsupported Pb-210 cannot be used as the indices that directly indicate the contents of some elements or nutrients except carbon contents. However, the concentration of two radionuclides may be used as indirect indices such as P-ava/P-t, C/P-org, (Fed-Feo)/Fet. These indices can give the information about chemical reactions occur in soils. (author)