Influence of magnesium emissions on epiphytic lichens in the vicinity of magnesite works Lubeník and Teplá Voda in the valley Muránska dolina was studied in 1973–1974. In 2003–2004 the site was revisited to assess potential changes after the thirty years. Decreased load of harmful substances distinctly reduced the size of lichen desert (territory where epiphytic lichens were totally absent). Nonetheless, an increased accumulation of Mg in thalli of Xanthoria parietina even in more distant localities from pollution sources was determined. Recent measurements of bark pH showed an outlasting high bark alkalinity (pH 9.1) in neighbourhood of an alkaline waste dump and values from neutral to moderately alkaline (7.06–7.73) in wide vicinity of both magnesite works. Subsequently development of nitrophilous components from the association Physcietum adscendentis with dominating Xanthoria parietina has been stimulated. Even so, the actual occurrence of more or less nitrophobous Hypogymnia physodes, Usnea sp. juv. or moderately nitrophilous Evernia prunastri and Ramalina fastigiata in a distance only 2 km from magnesite work Lubeník indicate future trend, although certainly a slow one, when nitrophobous species would return or even predominate.