Microfungi from soil of Polar Island Izvestia Tsik (Kara Sea).
The paper describes a complexes of soil micromycetes in Arctic island Izvestia TSIC as model polygon of human influence on micromycetes complexes in high Arctic. Soil samples from 7 groups of natural biocoenoses were studied by complex mycological methods including molecular analysis. The total of 54 micromycetes species were identified including 8 species of Zygomycetes (genera Cunninghamella, Mortierella, Mucor, Rhizopus and Umbelopsis). Most species belong to the anamorphic fungi. The genus Penicillium was dominated by the number of species (10 species), the genera Aspergillus, Cadophora and Cladosporium included 3 species. It should be noted that in addition to the filamentous microscopic fungi a significant part were represented by ascomycetous and basidiomycetous yeasts. The number of soil micromycetes on the island Izvestia TSIC ranged from 20 to 3500 CFU per 1 gram of soil. This index in the top soil layer of upland rock-moss-lichen polygonal plant communities ranged from 550 to 1500 CFU/g. The genera Geomyces, Cadophora and Phoma were dominant in such communities. But on the depth of 40-60 cm only the genus Cadophora was observed. The number of soil fungi was significantly increased (3500 CFU/g) in the animals habitats. The genera Geomyces, Phoma, Mucor and Umbelopsis formed the dominant group of micromycetes in such places. As a whole the dominance of the same species in a wide range of habitats was typical for Arctic natural biocoenoses. Low number of CFU/g, limited species composition and decrease of the number of species with depth were revealed for Arctic natural biocoenoses. Intrazonal communities were characterized by a low number of CFU/g and approximately equal ratio of the mycelium and spores. In coastal and wetland habitats fungi from the genus Cadophora were dominant. The soil mycobiota structure was changed under the influence of anthropogenic factors. Reduction in microfungi species diversity and abundance on the arctic soil contaminated by oil was revealed. But some increasing of micromycetes number was observed on the boundary of oil contamination. Complete change of microscopic fungi composition in contaminated sites was shown. Such species as Aspergillus niger, Cladosporium cladosporioides, C. herbarum, Penicillium aurantiogriseum, P. citrinum, Ulocladium sp. were dominant in these places. The following changes in the structure of soil mycobiota of Arctic communities under the influence of anthropogenic factors were revealed: - reduction in the number and the changing of the balance between spores and mycelium; - strong changes in the species composition of the soil fungi complexes, including the appearance of invasive species and reducing the number of native species. As a result, almost complete replacement of native species by invasive species was observed. The obtained results can be used for bio-indication of environmental change and anthropogenic influence on Arctic ecosystems. The structure of micromycetes complexes, volume and structure of biomass as well as the total number of fungi can be used as the bio-indicator indexes.