Lichens of carbonate substrates of the Patom Highlands (Eastern Siberia)

Abstract

The study of lichens of carbonate substrates of the Patom Highlands was carried out. 177 samples were collected and 28 species of lichens were identified. Among the discovered species there are representatives of both strictly calciphilous flora and lichens of the eurysubstrate group. Calciphilic species constitute a special group of lichens, usually xerophytic or even ultraxerophytic, and have a complex of adaptations to life on carbonate substrates, and adaptation strategies affect not only the fungal component, but also the photobiont. As adaptations to xerothermic habitat conditions, lichens are considered to have a squamous thallus, the presence of pruritus, an epinecral corteх of the thallus, as well as cyanoprokaryotes as a photobiont. Some of the discovered species of cyanobiotic lichens are rare in Russia, among such species are Synalissa symphorea (Weber) Poelt and Racodium rupestre Pers. Increased resistance to adverse climatic conditions is provided to them by blue-green algae as a photobiont, or rather, their mucous membranes surrounding cells and leveling the effects of high humidity - dryness, as well as temperature fluctuations. The carbonate substrates of the Patom Highlands are inhabited by a peculiar complex of lichens, among which there are both ecologically plastic, occurring quite often and under various conditions, and specific species with a narrow ecological amplitude. It is carbonates that are «guides» to the northern latitudes of heat-loving species that have a number of specific adaptations.