ZINC AND CADMIUM IN TREE SPECIES OF FOREST ECOSYSTEMS: PATTERNS OF TRANSLOCATION, ACCUMULATION AND BARRIER MECHANISMS

Abstract

This paper has been devoted to the problem of zinc and cadmium accumulation and distribution in the tree organs (on the example of forest ecosystems in the center of the East European plain). Using the translocation and discrimination factors it has been found that zinc as a rule translocated to the aboveground tree phytomass while cadmium was located to a greater extent within the roots. It has been found that the selectivity of the membrane transport systems of plantsincreased toward photosynthetic organs. It has been shown that the main reason of high cadmium accumulation in the stem wood is predominant cadmium xylem transport in the form of free ion Cd2+. In addition it has been foundsome aspects of species-specific accumulation of zinc and cadmium in tree species, associated with their geochemical specialization and peculiarities of the thiol compounds metabolism

Keywords

• tree species
• translocation and discrimination factors
• humidocationic plant species
• barrier function of organs
• selectivity of membrane transport systems