Corticolous Lichens of Belarus. II. Obligate and Facultative Epiphytes

The lichen biota of Belarus lists 406 corticolous species. Of these, 213 (35.7%) species are obligate epiphytes. Crustose lichens make up the majority of obligate epiphytes (157 species, or 73.7%). Apparently, this can indicate the decisive role of the morphology and chemistry of the substrate for the closely contacted lichen thallus. Facultative epiphytes are represented by 193 species, which are quite widely represented by foliose and fruticose life forms (51.3%). Facultative epiphytes inhabit rotting and processed wood, stony substrates, soil (including forest litter), mosses, leaves (needles), root turnouts and metal objects. Wood is inhabited by 154 facultative epiphyte species, of which 80 lichens are strongly epiphyticlignicolous. The lichen diversity of tree bark and wood is relatively similar; the value of the Sørensen-Dice index is equal to 0.51. Soil is the second most important substrate after wood for facultative epiphytes. It is inhabited by 55 lichens, most of which are represented by Cladonia and Peltigera species. 46 species of facultative epiphytes were found on mosses. These are represented mainly by cyanobiont-containing lichens, broad-lobed species, as well as many by the representatives of the genus Cladonia. The stony substrate is suitable for 43 facultative epiphytes species and is characterized by a high specificity of lichen biota. Its Sørensen- Dice index is equal to 0.13. Most of these representatives are common in urban environments. Fungi, lichens, root inversions, leaves, and metal are predominantly inhabited by multisubstrate lichen species.