The influence of immissions from the iron mines Nizna Slana on forest stands of Querco-Carpinetum was investigated. The vegetation is not directly menaced by sulphur compounds. Fe content was by 500% higher than in the control. Mn and Cu in the leaves of hornbeam were found at most 1500% and 1800% respectively higher than control. Cobalt, Ni and Cr in the samples were represented in relatively small amounts and are of low importance for phytoindication. Zinc was increased maximally by 542% compared with the control. Arsenic in the samples was increased up to a distance of 2200 m from the source of immissions; at a distance of 1400 m it was 2000% higher than in controls.