Abstract
In the neighbourhood of Kraków Usnea comosa, U. dasypoga, U. hirta occur. These species presently grow in the south-east part of the Niepołomice Forest only, which is situnled east of Kraków. In the years 1959-1960 the lichens appeared in the whole of the Forest. The author has confirmed that the Usnea species have died out in the western and northern parts of the Niepołomice Forest. The main reason for this is the increasing air pollution in Kraków - caused by the Lenin Metallurgical Works.