Biochemical cycles of metals in the environment: Factors controlling their content in the tissues of selected forest tree species
2002
Skrivan, P. | Navratil, T. | Burian, M. | Kvidova, O. (Akademie Ved, Prague (Czech Republic). Geologicky Ustav) | Vach, M. | Sequens, J.
Concentrations of Al, As, Ba, Be, Ca, Cd, Cu, Fe, K, Mg, Mn, Ni, Pb, Rb, Sr and Zn were studied in stem wood and bark of European beech and Norway spruce growing in soils developed on two contrast types of the bedrock (granite and sedimentary carbonates). Content of the elements was also determined in the assimilatory organs of beech, spruce, pine, alder and larch in dependence on the bedrock chemistry, site conditions and the organ age. Aim of the study was to assess the extent of incorporation of the elements into the forest vegetation as a background for the evaluation of their biogeochemical cycles. Variability in the concentration of the elements in the individual examined tree tissues is generally large. Higher concentrations of the elements in stem wood of the same tree species were found in trees grown on acidic bedrock and concentrations of Cd, Co, Cr, Mn, Pb and Zn were higher in the shallow rooting spruce stem wood, in accordance with their higher content in the topmost soil layers. The transfer indexes (TI of the elements expressed as the relative intensity of their incorporation into the wood mass with respect to their availability in soil show very low values for the toxic trace elements As, Be, and Pb, whereas the nutritional metals and their homologues Cd, Rb and Sr show values by one to two orders higher. Concentrations of Al, Ba, Be, Ca, Fe, Mn and Sr in the tree assimilatory organs tend to increase with the age of the organ, whereas the content of Cu, K, Mg, Ni and Rb shows gradual decrease. Concentrations of Ba, Be, Ca, Cu, Mg, Ni, Rb, and Zn in the leaves of beech growing on granite bedrock with high water table are higher compared to the trees growing on places with deeper water table. Lower concentrations of Ba, Be, Cu, Mg, Mn, Rb and Sr in beech leaves of trees growing in soils developed on carbonates than on granite are explained by the poorer accessibility of the elements. Varying values for As, Pb and Zn are caused probably by different intensity of their atmospheric fallout.
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