Se （selenium） is an essential trace element for both animals and human beings, although it is considered to be conditionally required for plants. Se occurrence in the environment of Moldova is poorly understood. The...Se （selenium） is an essential trace element for both animals and human beings, although it is considered to be conditionally required for plants. Se occurrence in the environment of Moldova is poorly understood. The objective of this study was to establish Se content and distribution in soils of this country. Se content in samples was detected using fluorometric method. Se concentration in soils ranged from 100 μg·kg^-1 to 668 og-kg-1 dry weight （mean 246 ± 73 μg·kg^-1）. Mainly, Se content in soils was optimal （more than 175 μg·kg^-1）, however, there were soil areas with Se deficiency （lower than 125/μg·kg^-1）. Maximum of Se in soils was observed at the depth of 0.4-0.7 m and then it decreased on going to parent rock. Se content typically increased with increasing of soil clay particles. Se washout from terraces and watershed slopes as well as Se accumulation in relief depressions was shown. High Se concentrations in local surface waters （0.2-6.1 μg·L^-1, mean 1.8 μg·L^-1） indicated the substantial presence of soluble Se forms, which were available to plants. Thus, geochemical conditions of Moldova are favorable for Se bioaccumulation by plants.展开更多
文摘Se （selenium） is an essential trace element for both animals and human beings, although it is considered to be conditionally required for plants. Se occurrence in the environment of Moldova is poorly understood. The objective of this study was to establish Se content and distribution in soils of this country. Se content in samples was detected using fluorometric method. Se concentration in soils ranged from 100 μg·kg^-1 to 668 og-kg-1 dry weight （mean 246 ± 73 μg·kg^-1）. Mainly, Se content in soils was optimal （more than 175 μg·kg^-1）, however, there were soil areas with Se deficiency （lower than 125/μg·kg^-1）. Maximum of Se in soils was observed at the depth of 0.4-0.7 m and then it decreased on going to parent rock. Se content typically increased with increasing of soil clay particles. Se washout from terraces and watershed slopes as well as Se accumulation in relief depressions was shown. High Se concentrations in local surface waters （0.2-6.1 μg·L^-1, mean 1.8 μg·L^-1） indicated the substantial presence of soluble Se forms, which were available to plants. Thus, geochemical conditions of Moldova are favorable for Se bioaccumulation by plants.
