Ксилотрофні дискоміцети деревних субстратів родини Betulaceae S.F. Gray. Національного природного парку «Сколівські Бескиди»

Abstract

Представлено результати досліджень біоти ксилотрофних дискоміцетів на відмерлій деревині представників родини Betulaceae S.F. Gray. та їхньої субстратної приуроченості в національному природному парку «Сколівські Бескиди». Наведено історію досліджень за цією тематикою. Всього ідентифіковано 16 видів ксилотрофних дискоміцетів на 5 деревних субстратах (Alnus glutinosa (L.) Gaertn., Alnus incana (L.) Moench, Betula pendula Roth., Carpinus betulus L. і Corylus avellana L.). Встановлено, що найбільш спеціалізованим серед ксилотрофних дискоміцетів є рід Mollisia sp., який представлений п’ятьма видами на деревних субстратах видів роду Betula L. Виявлено приуроченість ксилотрофних дискоміцетів до фракцій субстрату, а також їхню присутність на різних стадіях деструкції деревини.

Представлены результаты исследований биоты ксилотрофных дискомицетов на отмершей древесине представителей семейства Betulaceae S.F. Gray. и их субстратной приуроченности в национальном природном парке «Сколевские Бескиды». Приведено историю исследований по этой тематике. Всего идентифицировано 16 видов ксилотрофных дискомицетов на 5 древесных субстратах (Alnus glutinosa (L.) Gaertn., Alnus incana (L.) Moench, Betula pendula Roth., Carpinus betulus L. і Corylus avellana L.). Установлено, что наиболее специализированным среди ксилотрофных дискомицетов является род Mollisia sp., который представлен пятью видами на древесных субстратах рода Betula L. Выявлено приуроченность ксилотрофных дискомицетов по фракции субстрата, а также их присутствие на различных стадиях деструкции древесины.

Dead wood is important for biodiversity in forested ecosystems because it contains many microhabitats for different organisms. Wood-decay fungi are one of the most prominent organism groups among those dependent on woody debris. Wood-decay fungi have key-roles in the ecology of nemoral and boreal forests because they are the major agents of wood decomposition and nutrient cycling. Drastical decrease of the amount of woody debris in forests threatens biodiversity. The community structure of wood-inhabiting fungi is changed with mass loss of wood, but the relationship between substrate quality and decomposers is poorly investigated. Discomycetes is a former taxonomic class of Ascomycete fungi which contains all of the cup, sponge, brain, and some club-like fungi. It includes typical cup fungi like the scarlet elf cup and the orange peel fungus, and fungi with fruiting bodies of more unusual shape. A common feature of Discomycetes are the asci, which are typically produced on the surface of cup-like fruiting bodies. In most discomycetes, each ascus contains eight sexual spores that are forcibly discharged into the air when mature. The fungal diversity of Ukraine is still insufficiently and unevenly investigated. There is an exclusive situation concerning the National Natural Park «Skolivski Beskydy» territory. This research is a continuation of a series of publications devoted to biological diversity and ecological features of sac fungi including xylotrophic discomycetes in the forest ecosystems of the NNP «Skolivski Beskydy». Due to this research we make a further contribution to the fungal diversity investigation in the Skolivski Beskydy region. The study continues the research of the fungal diversity in the forest ecosystems of the NNP «Skolivski Beskydy». The National Natural Park «Skolivski Beskydy» is located in the Subcarpathian upland region of the Ukrainian Carpathian Mountains within the boundaries of Skole, Drohobych, and Turka districts of Lviv region. They are located in the basins of the Stryi and the Opir rivers. Their absolute heights range from 600 to 1200 metres. The climate of the NNP «Skolivski Beskydy» is mild, moderately warm and humid. Winter is characterised by frequent thaws and the temperature ranging from 0°С to +5°С. The average temperature in January is about -5°С, in July – +17°С. The annual precipitation is 800-1100 mm. The average thickness of the snow cover is 39 cm. On the territory of the National Natural Park «Skolivski Beskydy» one can still find the remains of pure beech forests and spruce fir forest stands, the totality of which occupies the highest position in the relief of the National Park. There are rare beech, sycamore and alder forests on some ridges. The most common on the territory are fir, spruce, beech-fir, and spruce-fir-beech forests with occasional sycamore and grey alder forests. The research was conducted during the autumn period of 2012–2014 by following the expeditionary-geographical method. The specimens of xylotrophic discomycetes were collected by the author. The specimens of xylotrophic discomycetes are deposited in the herbarium of the Lviv National University named after Ivan Franko (LW). The study was conducted only in the forest ecosystems. Attention was paid to xylotrpohic discomycetes on wood and bark of decaying tree species of the family Betulaceae. The following indexes have been registered in this research: wood substrate, stages of degradation of dead wood and the size of wood substrate. The nomenclature of the species follows the Index Fungorum database. The analysis of available literature has shown that there are few publications devoted to this subject. J.W. Groves and M.E. Elliott proposed a key for 11 discomycetous species of the family Sclerotiniaceae found on Alnus flowers and fruits. E. Kutorga indetified 47 discomycetous fungi found on the various parts of alder too. T. Schumacher recorded six amenticolous Ciboria species from Norway. Later the same author described five species of Sclerotiniaceae discovered on the leaves of birch and alder. Totally it has been found 16 species of xylotrophic discomycetes belonging to 11 genera, 5 families, 3 orders, 3 subclasses, 3 classes (Leotiomycetes O.E Erikss. Et Winka, Pezizomycetes O.E Erikss. Et Winka, Orbiliomycetes O.E Erikss. Et Baral), as well as anamorphic fungi incertae sedis, which belong to the group of order discomycetes. The taxonomic structure analysis has shown that Leotiomycetes are the largest among the classes of xylotrophic discomycetes, numbering 14 species. The Pezizomycetes and Orbiliomycetes classes are represented by one species. At the level of the most numerous families are Hyaloscyphaceae (7 species) and Helotiaceae (6 species). The only one species has been found in the families Bulgariaceae, Orbiliaceae and Pyronemataceae. This research has identified 16 species of xylotrophic discomycetes occurring on wood substrates of the family Betulaceae in the National Natural Park «Skolivski Beskydy». Five host genera have been represented by seven species: Alnus glutinosa (L.) Gaertn., Alnus incana (L.) Moench, Betula pendula Roth., Carpinus betulus L. і Corylus avellana L. The study of the affinity of xylotrophic discomycetes types to the development of different substrate fractions (size) has shown that there are 8 species of biota investigated on a coarse fraction (trunks, stumps), 2 species are on a small fraction (branch), 6 species have been identified on both fractions, that is, on large and small-scale substrates. The study of specialization at degradation stages of wood (according to Gordienko’s scale) has revealed the presence of xylotrophic discomycetes at all stages of decomposition of wood substrates, with the greatest number of species found at the fourth stage - 5 species of the genus Mollisia, 2 species of the genus Ascocoryne and 1 species of the genera Bisporella, Pseudospiropes, Dematioscypha, Scutellini and Orbilia. Bulgaria inquinans, Neobulgaria pura and Polydesmia pruinosa have been found at the second stage of decomposition of wood substrate. The first two species mentioned above have been recorded at the first stage of wood degradation as well. Bisporella citrina and anamorphic fungus Strossmayeria basitricha have been revealed at the third stage.