Effect of individual trees on the pH and the content of heavy metals in forest litters upon industrial contamination

The influence of individual spruce and birch trees on the distribution of heavy metals (Cu, Pb, Cd, and Zn) and hydrogen ions in the forest litter is considered in a territory subjected to long-term industrial pollution by emissions of the Ural copper smelter (town of Revda, Sverdlovsk oblast, southern taiga). In the background territory, the content of the elements regularly decreases from the tree trunks to the canopy gaps, whereas, in the contaminated territory, this relationship is either not traced at all (for the metal concentrations) or more weakly pronounced (for the metal reserves and pH values). The influence of trees on the spatial distribution of metals in the litter is specific for various elements and differs in coniferous and deciduous biotopes.