Kształtowanie się flory porostów zasiedlających głazy narzutowe [Formation of lichen flora populating erratic blocks]

The thesis includes the results of over ten years' research and observations of the population process of epilithic lichens on the newly exposed surfaces of erratic boulders. The research was carried out in the 'Kręgi Kamienne' Archaeological and Nature Reserve located in the Tucholskie Forest (N Poland). The thesis presents the seąuence of population and the quantitative changes of pioneering lichens. The following phases of initial stage of succession, which have lasted for at least 30 years, were distinguished and characterized: the phase of pulverulent lichens, the beginning phase of Lecidea fuscoatra domination and the phase of boulders population by Porpidia and Rhizocarpon genera species. The optimal stage was specified on the basis of initial population of foliose lichens and formation of epilithic lichen associations