Abstract

This chapter focuses on peculiarities of lichen symbiosis and of lichen-forming fungi in comparison with non-lichenized taxa, photobiont diversity, photobiont-derived mobile carbohydrates, specificity of lichen symbiosis, modes of dispersal, functional thallus anatomy, mycobiont-photobiont interactions and the role of hydrophobic and hydrophilic fungal cell wall compounds with regard to gas exchange and water relations of the symbiotic system, foliicolous lichens, lichen growth in extreme climates, poikilohydric water relations and drought stress induced reversible cytoplasmatic cavitation, ice nucleation, uptake and accumulation of ions and radionuclides, sources of fixed nitrogen, mycobiont-derived secondary compounds. Economic perspectives are briefly summarized.