A comparative study on radiocaesium ( 137Cs) uptake from coniferous forest soil

Abstract

Radiocaesium ( 137Cs) uptake from a coniferous forest ecosystem with soil characterized by a high fraction of organic matter and low pH was studied using sheep's fescue (Festuca ovina) as indicator in a pot experiment and compared with bilberry (Vaccinium myrtillus), lingonberry (Vaccinium vitis-idaea), and heather ( Calluna vulgaris) taken from an area of coniferous forest. Results obtained on an average basis showed a slight variation within 137Cs uptake values in all tested plants. Based upon the soil-plant relationship (Bq kg −1 plant DM/Bq kg −1 soil DM), 137Cs transfer factors (TF) were calculated. Sheep's fescue TF in the two harvests (growing periods of 13 weeks each) ranged from 0.03 to 3.45, with a mean of 0.35 ± 0.42. Field plants showed higher 137Cs TF when compared with sheep's fescue. Bilberry TF ranged from 0.28 to 2.30, with a mean of 0.85 ± 0.49. Lingonberry TF ranged from 0.57 to 4.46 with a mean of 1.35 ± 0.78. Heather TF ranged from 1.80 to 8.89 with a mean of 3.31 ± 1.53. Radiocaesium transfer coefficients (TC, Bq kg −1 plant DM/Bq m −2) of field plants were also calculated. Heather 137Cs TC was the highest among all tested plants and ranged from 0.38 to 0.64 with a mean of 0.49 ± 0.05. The results demonstrated that 137Cs transfer parameters of pot experiment with sheep's fescue show no significant differences between the obtained transfer factors, using soils from bilberry, lingonberry, and heather sites.