Home – Home – Jornals – Contemporary Problems of Ecology 2018 number 5

We present data on the diversity and ecophysiology of fungi from one of the most alkaline natural habitats on Earth - soda Lake Magadi, a place where pH values can exceed 11-12. It has been shown to harbor abundant prokaryotic organisms that form complex communities along with algae and few other eukaryotes. In the current study, we isolated and characterized 22 filamentous fungal species from Magadi Lake coasts using systematic approach, which involved selective recovery, morphological and phylogenetic analyses, growth experiments estimating pH and temperature preferences, NaCl dependence. We demonstrated that fungi with different types of adaptation to alkaline conditions were present in soda soils. Alkaliphilic and alkalitolerant fungi belong to different families of Ascomycetes , predominantly to Plectosphaerellaceae, as well as Onygenaceae, Trihocomaceae, and Pleosporaceae. Sodiomyces tronii and S. magadii are represented as new obligate alkalophilic species within the previously monotypic genus Sodiomyces (Plectosphaerellaceae). According to the results of growth experiments obligatory alkalophilic isolates exhibit therm- and halotolerant properties. The problems of adaptation to the external pH, possible substrate preferences and association of alkalophilic fungi with other organisms are discussed.

The results of the investigation of microscopic fungi complexes in the regions of five Russian polar stations in East Antarctica and the Subantarctic are presented in the article. A total of 104 species of microscopic fungi were identified. In samples of soils and anthropogenic materials from polar stations of East Antarctica (Progress, Mirny, Molodezhnaya, Druzhnaya-4) 77 species of fungi were detected by mycological methods, while 87 species of micromycetes were isolated from the Bellingshausen station (Subantarctic). The number of fungi in soils varied from individual propagules in control soils to 94,000 per gram of soil in contaminated areas. The largest number of species is represented by the genus Penicillium (26 species). The species of fungi that form the core of mycobiota in most of the studied habitats have been identified. For soils of East Antarctica it is formed by species of the genera Aureobasidium, Cadophora, Pseudogymnoascus ( Geomyces ), Thelebolus, and Phoma . There are significant differences in the mycobiota of East Antarctica and the Subantarctic. At the same time, the general tendency of the increase in the species diversity and the number of fungi in the areas of polar stations in comparison with the control (clean) sites for all studied territories was noted. The obtained data indicate that a significant part of micromycetes enters into Antarctic together with the man (anthropogenic invasion).

The results of more than a century history of study of taxonomic and ecological structure of basidial macromycete biota in polar deserts of the Northern Hemisphere are discussed. Nowadays, 77 species of macromycetes, among which 40 species are Agaricoid and 30 - Aphyllophoroid fungi, and 7 are Gasteromycetes, are known from this region. The greatest number of species is known for the Franz Josef Land archipelago and the Severanya Zemlya. All the identified species of Agaricoid and 86 % of Gasteroid fungi are aboriginal representatives of extremely high latitudes, collected under natural conditions, whereas 80 % of the Aphyllophoroid fungi are alien elements. All alien species are able to exist in the region exclusively in the human-modified habitats, colonizing anthropogenic woody and grass substrates, and disappear with the depletion of these resources. Despite the existence of mycobiota at the limit of the global thermal gradient, a concrete species complex of macromycetes that does not occur anywhere in the world is formed here. The most adaptable to such extreme conditions are symbiotrophic species (basioliolichens and mycorrhiza-forming). The general features of the organization with the Antarctica mycobiota are established. The possibility of new species appearance in the region is discussed in connection with the intensification of human economic activity and global climate change.

The results of a multi-year complex study of species diversity, features and patterns of distribution, substrate colonization and ecology of soil microscopic fungi in the lowland, piedmont and mountain monsoon rain forests of Vietnam are presented for the first time. In 97 forest habitats studied within 13 specially protected areas of Vietnam, located in the northern, central and southern parts of the country, 510 species of micromycetes from 148 genera were identified. The influence of environmental factors (climatic features, relief, soils, forest types, and others) on the formation of complexes of micromycetes was analyzed, as a result the dependence of the number of colony forming units (CFU) on the type of the substrate and season (wet/dry) was established: in dry season (October - March) significantly more species were detected ( p < 0.05) compared with the wet one, and many species were associated with specific plant species. Indicators of species diversity decrease with increasing altitude above sea level ( p < 0.01). In this case, the ratio of the taxonomic groups of micromycetes naturally changes. A latitudinal-zonal trend is revealed in the change of the species composition of microscopic fungi determined by a combination of environmental factors.

The results of 40-year monitoring of agarics in four types of pine forests in the Perm Krai are summed up (southern taiga subzone). We have learnt that species number in the pine forests varies from 80 (sphagnum pine forest) to 194 (lichen pine forest). We have shown the changes in species composition and the increase of species diversity in each period of the monitoring. We have analyzed ecological structure and defined species that are dominant by their number and biomass. Despite the changes of the species composition, ecological groups ratio in each forest type remains almost the same. The common feature is that mycorrhizal fungi prevail in the pine forests by species number (55.5-61.2 % of all the species number in the cenosis), as well as by yield (52 % of the total number and 94 % of total biomass). We have studied connection between species diversity and productivity of agaricomycetes and the climate. We have found that July rainfall is favorable for the “fruit bearing” of agarics in the pine forest with moderate humidity in August ( rs = 0.73). In swampy cenoses June rainfall, on the contrary, has negative impact ( rs = -0.70).

The influence of the degree of decomposition and acidity of wood, as well as the illumination of the micro-habitat on the species composition, abundance and occurrence of Myxomycetes of xylobiontic (inhabitants of the wood) substrate complex of forest communities in Siberia (Altai kray, Altai Republic, Novosibirsk Region). The work is based on the study of 1777 samples of fruit bodies (sporophores) Myxomycetes. In the analysis of data for communities of Myxomycetes of xylobiontic substrate complex was recognized clearly correlate with the degree of decomposition of the wood. The study of distribution of species composition of the slime mold on the wood of various degree of decomposition showed that the maximum number of species observed on dead trunks where the wood is of medium density and bark can easily be separated (W3). The smallest specificity and diversity of species composition was observed on the fellen trunks of trees with very dense wood and dense bark (W1). This dead tree has low water-retaining capacity, and the tight bark and the wood is almost intact, containing large amounts of lignin, preventing insight into the interior of the barrel of plasmodium and myxamoeba of Myxomycetes. The study of the location of the colonies of slime molds in relation to the light level showed that the greatest number of species is found on the front, side and bottom parts of dead trunks of woody plants. The lowest specificity and the least variety of species of Myxomycetes, found on the top, facing the sun, parts of dead tree trunks. An exception are species with compound fructifications, for example, such as Fuligo septica, Reticularia splendens , which are most often observed on the upper parts of the sunlight-facing trunks of woody plants. It is noted that acidophily of species of the genera Comatricha and Cribraria could be documented for decaying wood and bark of living trees.

The number and taxonomic structure of the complex of micromycetes are determined and the species capable of active functioning in the sediments (bottom soils) of the White Sea (littoral and at depths of 10-30 m) are revealed. The number of fungi in the soil is small (from hundreds to several thousand colony - forming units (CFU) in 1 g), and the species richness is quite significant. A total of 70 species was distinguished,, most of them (90 %) were anamorphs of Ascomycota (Capnodiales, Eurotiales, Hypocreales, Pleosporales, Saccharomycetales and Incertae sedis ) , the species of Zygomycota ( Mucoromycota ) - orders Mucorales and Umbelopsidales (8 %) and Basidiomycota - order Agaricales were less (2 %). Fungi, actively functioning in the soil were established by the ability to develop in the organic substrates (starch, cellulose, chitin, pieces of thallus laminaria), growth on media with seawater at low temperatures and at different levels of oxygen, i.e. conditions similar to those in the ecotope studied. This group of fungi includes about 20 species - Paradendryphiella salinа, Acremonium tubakii, A. potronii, Pseudeurotium hygrophilum, Pseudogymnoascus pannorum, Emericellopsis sphaerospora, Oidiodendron periconioides, representatives of genera Tolypocladium, Sarocladium, Parengyodontium album, Lecanicillium muscarium. They are characteristic of the marine and cold habitats, some of them are known as chitinolytic, associates of insects and algae, many of them grow in anaerobic conditions. In some species, this ability was discovered for the first time ( Aspergillus brasiliensis, A. sydowii, Cladosporium cladosporioides, Emericellopsis sphaerospora, Oidiodendron periconioides, Pseudeurotium hygrophilum, Tolypocladium cylindrosporum, T. tundrense, Umbelopsis vinаcea , some species of the genera Penicillium and Talaromyces ). Further study is required for detailed ecophysiological characterization of marine isolates of species that can function in bottom soils.

The results of a 20-year study of spatial distribution of clavarioid mycobiota in the West Siberian Plain are discussed. The species structure was studied at two scales: a regional (an area of 100,000 km2) and a local (100 km2) ones. One hundred twenty one species of clavarioid fungi were found in the study area. The patterns of spatial variability of species diversity on the plain were revealed. At the regional scale, the maximum species richness of fungi is observed in hemiboreal forests (104 species), while at the local scale it ranges from the middle boreal to hemiboreal (54.3-54.5 species). With the increasing pessimality of the hydro-thermal regime, at both scales, the number of species decreases sharply in the direction of the tundra and steppes. When studying the distribution of diversity among the localities, changes are observed not only along the latitudinal gradient, but also in the longitude sectors: in the forest zone, the richest localities are located on the western and eastern edges of the plain, while in the extensive marshy areas in the center the number of species is lower ( p < 0.05). A map of the spatial distribution of species diversity for the local scale is constructed. The correspondence of the spatial distribution of the studied group of fungi to a global latitudinal gradient is discussed. The main abiotic factors forming a variety of the studied group of fungi in the region are revealed.

According to the quantitative account the aphyllophoroid macromycetes of a Betula-complex on 207 sites of the territory of the West Siberian Plain in the range from the forest-tundra to the forest-steppe, width and zone consistent patterns of the biota of the xylotrophic fungi are determined. It is shown that the structure of width and zone xylomycocomplexes of the region is defined, first of all, by the climatic factors which are characterized by the expressed hydrothermal gradient and influencing fungi as directly, and through formation of the forest stands corresponding to climate. The sequence of width and zone xylomycocomplex of the region is offered as a scale for indication of forest vegetation conditions and parameters of a forest stand of the concrete timberland. Possibilities of indication are expanded with differentiation of xylomycocomplex and, respectively, its width and zone scale on functional fractions of fungi (stem, peripheral and wound types). The scale is used for an assessment of a condition of the woods of the natural park “Numto” (northern taiga) and approved on its 15 various wood lots. For the characteristic of each site coefficients of correlation of numerical structure of this mycocoenosis and the zone xylomycocomplex in the range from the forest-tundra to the forest-steppe taken as in general and on functional groups are calculated. The configuration of the spectral curves of a site received thus and their mutual situation shows features of the hydrothermal mode of a site, impact on a forest stand of mechanical damages, its physiological state, completeness, site class, age. In particular, by results of the carried-out mycological indication, forest vegetation conditions of the timberland of park broken by cabins and the fires correspond to forest vegetation conditions of the zones lying to the south of the park territory. Noted regularities of the West Siberian width and zone xylomycocomplexes scale are characterized by the defined universality for a forest biome of Siberia that is confirmed by the similar regularities received when studying high-rise and zone distribution of xylomycocomplex of Transbaikalia.