A study of trace elements in plants of the Polar Urals and Chukotka in the search for metallophyte hyperaccumulators

Abstract

The present study summarizes the results of investigations of the trace element distribution in soils and their uptake by plants of natural habitats on the ultramafic and acidic rocks of the Polar Urals and Chukotka in the Arctic Russia. Concentrations of Fe, Mn, Zn, Cu, Ni, Cr, and Co were determined by atomic absorption spectrometry in 194 plant species of 30 families and 157 soil samples. Two leaches were used for the soil – 1 M ammonium acetate (exchangeable) and 1 M HNO3 (acid soluble); a mixture of 1.5 M HNO3 and 3.7 M HCl was used for the plants. The levels of Fe, Cr and especially Ni in the soils on the ultramafic rocks exceeded those of soils on the acidic rocks. The mineral composition of plant species varies depending on the differences in chemical and mineralogical composition of the two soil-forming rock types. Taxon-specific features in the accumulation of potentially toxic elements in plants of these regions have been revealed for the first time. The data on the metal accumulation ability of plant species show that the species Thlaspi cochleariforme DC. and Alyssum obovatum (C.A. Mey) Turcz. (Brassicaceae) could be considered as Ni hyperaccumulators. These species could therefore have potential for Ni phytoextraction from contaminated soils.