In this dissertation, the mycobiota of wood-decaying basidial fungi in the mountainous part of the Bystrytsia Nadvirnianska river basin was studied, along with the analysis of its taxonomic and ecological structure and revealing its rare component. The concept of "wood-decaying fungi" in this work is interpreted as broadly as possible, including all species involved in the wood decomposition process.
Based on the results of our field research, processing of herbarium materials and literary sources, a total of 303 wood-decaying basidial fungi species were recorded in the study area. The presence of 197 species was confirmed through our samples or observations. The species belong to 177 genera, 72 families, 17 orders and five classes. The largest orders are Agaricales (96 species), Polyporales (78 species), Hymenochaetales (40 species) and Russulales (25 species), all belonging to the class Agaricomycetes.
In total, 95 species of wood-decaying basidial fungi were found in the area for the first time. Eight species are new to the mycobiota of Ukraine: Aphanobasidium subnitens, Ceraceomyces eludens, Globulicium heimale, Hyphoderma occidentale, Hypochnicium albostramineum, Hypochnicium cremicolor, Steccherinum robustius and Sistotrema alboluteum. Additionally, four species of fungi, known only from historical finds in Ukraine, were rediscovered. Among the recorded species, three are listed in the Red Data Book of Ukraine: Amylocystis lapponica, Grifola frondosa and Hericium coralloides.
The mycobiota of wood-decaying basidial fungi of the studied area was compared to species lists of other well-studied areas of the Ukrainian Carpathians. In this regard, Hutsulshchyna National Nature Park turned out to be the most similar to the study area due to the similarity of the vegetation cover and the degree of scrutiny of these territories. The mycobiota of wood-decaying fungi of the mountainous part of the Bystrytsia Nadvirnyanska river basin, on the one hand, is typical for the Ukrainian Carpathians and includes widely distributed fungi confined to the wood of the main tree species of the region. On the other hand, it is has pronounced specific features, both due to the presence of a rare component and the representation of the fungi confined to all major plant communities of the region, in particular forests with Pinus cembra.
Since the object of the study is the wood-decaying mycobiota, the absolute majority of the registered species are obligate xylosaprotrophs (229 species). Facultative saprotrophs (24), facultative parasites (22), obligate parasites (13), mycotrophs (5), bryotrophs (1), mycorrhiza-formers (7) and basidiolichens (2) are less common.
Data on the substrate affiliation of 263 species of wood-decaying basidial fungi, which were reported from the wood of 28 plant species, was analyzed. The largest number of fungi was registered on the wood of Fagus sylvatica (116 species), Picea abies (98), Abies alba (28) and Alnus incana (23).
In total, 213 species of wood-decaying basidial fungi, which could be assigned to the habitat type, were recorded in 16 biotopes. The largest number of species was found in biotopes Д1.1.2 Central European neutrophilous beech forests (77 species), Д2.1.3 Fir and spruce forests of lower part of the forest belt on rich soils (68), Д2.1.2 Mountain spruce forests on poor soils (42) and Д1.1.3 Acidophilous beech forests (41), occupying the largest areas in the study territory. The conducted cluster analysis of the lists of species recorded in the main types of habitats demonstrated a clear division between deciduous and coniferous biotopes. The percentage of brown-rotters in coniferous forests is significantly higher than in deciduous ones.
Within the cluster of coniferous biotopes, the species composition of wood-decaying basidial fungi of forests with Pinus cembra was the most original. In total, 31 species of fungi were registered there, five of which are new to Ukraine, and four were indicators of the high nature conservation value of forest ecosystems. The species composition of Basidiomycota per individual fallen log turned out to be rather poor. The fungi forming thin resupinate corticioid basidiocarps on the substrate underside prevail among the finds, indicating a lack of moisture in the surveyed stands.
Regarding reliability of the Phellinus viticola distribution on the availability and spatial connectivity of suitable substrata and the abundance of its recognizable basidiomata, we consider it a convenient indicator species of the conservational value of coniferous forests of the upper part of the forest belt in the Ukrainian Carpathians.
Within the study area, two hotspots of the rare wood-decaying basidial fungi diversity were discovered: Gorgany Nature Reserve and the forests of the Hvizd Low Mountains. We recommend establishing the Nadvirna Mountains Regional Landscape Park on the entire territory of the latter.
