Trees and shrubs from a post-industrial area high in calcium and trace elements: the potential of dendroremediation

The aim of the study was to evaluate the metal(loid)s phytoextraction potential of trees: Betula pendula Roth, Pinus sylvestris L. and the shrub Salix viminalis L. Plants of different ages were selected from a post-industrial area with an unusually high content of calcium (Ca) and trace elements in the soil. The content of 39 metal(loid)s in trees and shrub organs and physicochemical soil parameters were determined. A comparison of these species with control plants was also an object of the study. The polluted soil was characterized by worse physicochemical conditions and a much higher content of almost all the analyzed elements in comparison with the control. The older the plants, the greater their total biomass, with the control plant biomass being significantly greater in each case for all treated plants. According to the total content of all determined elements jointly, the most enriched was the oldest, a 7-year-old specimen of S. viminalis. The obtained results suggest that the high Ca concentration and the alkaline reaction (8.83) of polluted soil limit the uptake of most elements by tested plants. It can be concluded that despite the reduction of biomass, this limitation allows plants to better adapt and survive under challenging conditions. Excessive concentration of elements, even nutrients such as Ca, may act as an inhibitory factor for the uptake of other elements. Moreover, phytoextraction ability may significantly vary in different woody plant species and ages, which is an essential practical aspect in dendroremediation application.