INFLUENCE OF URBAN ENVIRONMENT ORIGINATED HEAV Y METAL POLLUTION ON THE EXTRACTIVES AND MINERAL SUBSTANCES CONTENT IN BARK AND WOOD OF OAK (QUERCUS ROBUR L.)

Abstract

Extractives and mineral substances contents were analyzed in oak wood and bark ( Quercus robur L.) which was sampled from the polluted environment. Results were compared with corresponding values in bark and wood of oak from unpolluted environment. Samples were collected from butt-end, middle and top section of three trunks of cca. 100 years old oaks which were grown in polluted environment. Pollution originated from “Żeran” heat and power plant and “ArcelorMittal” foundry. Three trunks of cca. 100 years old oaks which were grown in unpolluted environment in Mazury-Podlasie region were examined for comparison. 200 mm thick disks were cut off from each mentioned above part of trunks. Five zones were distinguished on the each cross-section: Pith adjacent wood, heartwood, sapwood adjacent heartwood, sapwood and bark. Following analyses were performed in samples taken from all zones: extractives determination, mineral substances determination and content analysis of: Nitrogen (N 2) (Kjeldahl method), calcium (Ca), magnesium (Mg), iron (Fe), copper (Cu) (ICPAES technique), potassium (K), lead (Pb), cadmium (Cd) (GFAAS technique). Our results show that environmental pollution significantly influences content of examined substances. It causes the increase of extractives content in wood, and decrease of the extractives content in bark. Nitrogen content is generally lower and analyzed metals contents are higher in polluted wood in relation to unpolluted one.