Biomonitoring of heavy metals using higher plants growing at former mining sites

The principal purpose of the present work is the study of the heavy metal contamination of higher plants growing on the soils of former mining sites. Different plant species were compared with respect to their use in the monitoring of heavy metal pollution. The study sites are located in Germany; Bleialf (a former Pb mining area), and Donnersberg am Imsbach (a former Cu mining area); and in Luxemburg: Dudelange (a former Fe mining area and current cinder dump). An area near Trier, Rheinland-Pfalz was chosen as control site. The heavy metals Cd, Pb, Cu, and Zn were analyzed. Soil samples were collected from the surface horizon (0-15 cm). The total contents of the heavy metals were determined. The metal solubility was evaluated by the use of different extraction methods (CaCl_2, NH_4Cl and EDTA). Moreover, chemical soil properties (pH, CEC, and organic carbon content) which can influence the metal solubility, and consequently the metal availability to plants, were determined. Betula pendula, Populus tremula, Quercus robur and Quercus petraea, Salix caprea, Sambucus racemosa and Sorbus aria, and Sorbus aucuparia were chosen as test plants. Plant samples were collected at two seasons of the year - summer (leaves) and winter (buds). The plant contents of the heavy metals Cd, Pb, Cu, and Zn, as well as the contents of the nutrients P, K, Mg, and Ca were determined. The heavy metal concentrations in the soil and plants were correlated in order to evaluate the efficiency of the extraction methods, and the use of leaves and buds in the prediction of the heavy metal availability. Interchanges of the heavy metals and the plant macronutrients were also analysed. (orig./UWA)SIGLEAvailable from TIB Hannover: H93B5961 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman