[in German with English abstract: ] Distribution of lichens on block fields is influenced by a complex system of interacting exogenous factors. Next to the large-scale influence of macroclimate and chemical properties of the substrate the microclimate is of special importance. Reproduction and interaction of the symbiotic organisms are also relevant aspects. The lifestrategies of the different species show a high degree of adaption to the conditions of the habitats. Keywords: lichens, microclimate, succession, interaction, life-strategies.