Vertical Distribution of Communities of Epiphytic Myxomycetes on Woody Introduced Plants in Siberia

The taxonomic diversity of epiphytic myxomycetes depending on the height of the trunk on living woody plants in the arboretum of the Central Siberian Botanical Garden, Siberian Branch, Russian Academy of Sciences (CSBG SB RAS), has been studied. All samples of myxomycetes are obtained by cultivation by the method of moist chambers in the laboratory in Petri dishes. Sampling of bark from living woody plants is carried out at a height of trunks from 0 to 15 m from the soil level. The experiment involves nine species of introduced deciduous woody plants Fraxinus pennsylvanica, Prunus maackii, Populus alba, Salix alba, S. pentandra, S. triandra, Sorbus aucuparia, Tilia cordata, and Jungles mandshurica . As a result of data analysis, 51 species of myxomycetes are revealed. It is noted that the species composition of myxomycetes on the studied woody plants differs significantly from that on native tree species growing on the territory of the botanical garden. Two species of the genus Arcyria and Trichia new for science, 3 species new to Russia ( Didymium clavodecus , D. ovoideum , and D. synsporon ), and 18 species new for Novosibirsk Region have been identified. A description of species new to science is given; photographs of sporocarps, spores, and capillitium studied using light and scanning electron microscopy are provided; and a comparison with morphologically similar species is made. A change in the taxonomic composition of myxomycete communities depending on the height of the trunk is established. On the bark collected at the roots of trees, 25 species of myxomycetes have been identified; at a height of 1.5 m, 18; at a height of 5 m, 32; at a height of 10 m, 14; and, at a height of 15 m, 17. Representatives of the genus Perichaena are found at all heights, but the greatest species diversity is noted in the basal part, where seven species are noted, while species of the genus Didymium have the maximum species diversity (six species) at a height of 5 m, including three species new to Russia, noted only at this height. The distribution of the number of samples by height showed that the bark of living woody plants is most abundantly populated at a height of 5 m (72 samples) and at the root (50 samples).