Assessment of Lichens as Biomonitors of Heavy Metal Pollution in Selected Mining Area, Slovakia

Lichens have widely been used as bioindicators to reflect the quality of the environment. The present study was conducted to investigate the lichens diversity that grows on the surface of waste heaps from an abandoned old copper mine in Mlynky, Slovakia. In spite of the heavy metal-contaminated environment, we documented twenty species of lichens in the selected site. Taxonomically the most numerous group were represented by Cladonia with seven species, as well other species; namely, Acarospora fuscata, Cetraria islandica, Dermatocarpon miniatum, Hypogymnia physodes, Hypogymnia tubulosa, Lecanora subaurea, Lepraria incana, Physcia aipolia, Porpidia macrocarpa, Pseudevernia furfuracea, Rhizocarpon geographicum and Xanthoria parietina. The content of selected heavy metals (Cu, Fe, and Zn) in the predominant lichens Cetraria islandica, Cladonia digitata, Cladonia pyxidata, Hypogymnia physodes and Pseudevernia furfuracea were analyzed. The highest content of Cu, Fe, and Zn was found in Cladonia pyxidata collected from mine-spoil heaps with concentration 46 ± 4.4, 82.5 ± 22.6, 4.8 ± 1.6 mg/kg, respectively. Interestingly, Cladonia pyxidata collected from the forest surrounding the location showed 15 times lower concentration for Cu. Additionally, similar results were found for Fe and Zn