Retention and Loss of Cesium-137 by Components of the Groundcover in a Pine (Pinus Virginiana L.) Stand

Abstract

Retention, accumulation, and loss of 137Cs by Hchen, moss, needle litter, and plant rosettes were measured in a laboratory experiment. Cesium-137 was added to these forest floor components for 3 months in simulated rain, after which they were leached out with rainwater for 5 weeks. Accumulation was proportional to 137Cs input. Retention increased in the order plant rosettes (72%) < lichen or needles < moss (96%). Biological uptake, as indicated by differences in retention between live and dead components, accounted for only 4-8% of the total retention. Underlying soil reduced retention by needles and lichen about 1/3 and 1/2, respectively. Loss of accumulated 13?Cs was more rapid from dead plants than from live ones. Resulting half-times varied between 0. 8 and 2.4 years. The calculated 137cs retention by the entire forest floor was 93%.