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The impact of Cracow conurbation on small forest ecosystems was studied during the last four years (1998-2001). Seven sites located at different distances from the city and from busy road were selected. Lichen Hypogymnia physodesfrom unpolluted areas were transplanted 10 each of investigated sites for 6-month period (winter 1998/1999, 1999/2000, summer 2000). The quantity of litter fall with percentage cmposition of each species was estimated, also the input of litter and heavy metals to the forest floor were evaluated. Metal concentration (Cd, Pb, Cu, Zn, Fe) in Hypogymnia physodes, leaves of common oak, hornbean and litter fall were determined in IL 251 flame AAS. Acute injuries of lichen thalli as well as concentrations of Pb, Zn, Fe and S were higher after winter transplantation and in sites located close to Cracow conurbation. High concentration of heavy metals were noticed in tree leaves from eastem transect as the effect of steel works emission as well as in those sites from southem transect situated nearby the city. Although air pollution har generally declined in the Malopolska district over the last few years the metal concentration and input to the forest flow in 2001 remains at the same level than in the previous years.

Leaves of Vaccinium myrtillusL. were collected from the forest site influenced by emission, containing chromium compounds in high amounts, from the chemical industry “Alwernia", located 20 km west of Krakow (Poland). As the control area the forest 10 km west of studied site was chosen. Three compartments of the leaf were distinguished: surface, when with together with embedded elements were removed by procedure of dipping in almost boiling water [1], inside the tissue but free ions, by extraction in 20% ethanol +1% acetic acid [2]; bound ions, which could be removed only by analysis of `leftover tissues'. Chromium and other element (Cu, Zn. Fe) levels were analysed by atomic absorption spectrometry, in each of studied leaf compartments-to establish their possible interactions and localisation. Transmission Electron Microscopy revealed disturbances in cell organelle structures. Additionally with the histochemical method we localised phenolic compounds in the cell, considering their involvement in heavy metals detoxification.