Vol 12, No 1 (2019)

Materials collected in the flatland and highland parts of Western Siberia in the second half of the summer in 1954–2016 have been used to analyze the zonal and provincial aspects of the biotope distribution of the northern red-backed vole Myodes rutilus. The previously reported preference of the species for flatland and mountain forests with the contribution of dark coniferous tree species within the taiga zone of the plain, northeastern Altai, and Kuznetsk Alatau has been confirmed. Cluster analysis of the matrix of similarity coefficients of the abundance has been performed and used to classify northern red-backed vole habitats according to the optimality of environmental conditions (favorability) for this species. At the same time, this classification is a cluster arrangement of the abundance representations at the territory under consideration. Five types of conditions—optimal, suboptimal, subpessimal, pessimal, and extremal—have been identified, with the first type divided into two subtypes. The differences in northern red-backed vole abundance between habitat subtypes are less pronounced than the differences between the types. The classification and the structural graph reveal the dependence of abundance on a range of factors and regimens (inseparable combinations of factors). The factors for the entire Western Siberia are as follows: heat and water supply, macrorelief characteristics (plain or mountains), vegetation type, degree of afforestation, species composition of the tree stand in the forests, flooding during seasonal floods, waterlogging, ploughing, and the degree of area development. The zone-subzone differences affect the distribution of the species under consideration only on the plain, whereas provinciality and altitude zonation affect the distribution only in the mountains. The strongest correlation with northern red-backed vole distribution in Western Siberian habitats is observed for heat and water supply (zonality and subzonality on the plain and altitude zonation in the mountains). Our studies of the distribution of this vole refine the results of analysis performed by our predecessors and give a more detailed pattern of species distribution over the habitats.

The intraspecific relationships between individuals in experimental conditions of two populations of Shikotan vole Myodes sikotanensis from Sakhalin and Shikotan islands are described. We have studied the interactions and acoustic activity of voles in groups consisting of four males and two females. We observe aggressive and friendly behaviors in the groups of both populations. However, voles from Shikotan Island are more active and show more friendly behavior, which is characteristic for gray voles. Voles from the Sakhalin population have mainly aggressive interactions, and hierarchical relations of domination-subordination form between them, which is characteristic for bank voles. The acoustic signals are mainly squeaks emitted by the voles when protecting their shelter or during other interactions of the individual that experienced discomfort. Acoustic signals do not play an essential role in the formation of relationships in the groups of Shikotan voles.

We have studied communities of nematodes in the basal soil of woody plants introduced in the open areas of the Polar-Alpine Botanical Garden of the Karelian Scientific Center of the Russian Academy of Sciences (RAS) in Murmansk oblast. Under the conditions of introduction, we have identified nematodes belonging to 48 taxonomic categories with the maximum diversity of bacteriotrophes (56% of the total number of identified taxa) and plant parasites (21%). The tendency of reducing the number of genera in the series “deciduous breed-conifer breed-natural biocenosis” is shown; a similar pattern is shown for the group of plant parasites. We have found parasite taxa rare for the northwest of Russia. An adaptive mechanism was found in nematodes of the species Rhabditis producta Schneider, 1866, associated with delayed egg laying and their subsequent development to larvae in the body cavity of females, which is of great importance for the survival of offspring in adverse environmental conditions in the north. The study has revealed a significant correlation between the taxonomic diversity of nematodes and most of the soil properties (pH, ash content, N, and P); the relative abundance of polytrophs and nematodes associated with plants and the content of organic matter, organic carbon, as well as the C : N ratio; and the relative abundance of the group of nematode parasites of plants and the area of vegetation projective cover.

The ecological conditions of habitats and demographic parameters of Pulsatilla patens (L.) Mill s.l. in ten cenopopulations (CPs) in Kirov oblast are assessed. It has been established that the species generally inhabits green moss and herbaceous pine communities dominated by anthropophobic species within the studied part of the range. A large proportion of anthropotolerant species is characteristic of phytocenoses that are significantly exposed to anthropogenic pressure. P. patens s.l. is a hemistenobiotic species. The amplitude of the ecological space of the studied P. patens s.l. CPs under the conditions of Kirov oblast does not exceed the limits of the ecological range according to Tsyganov’s scales (1983); however, the values of the soil humidity scale are close to the maximum limit, while the values of the humidity factor scale are close to the minimum limit. The discomfort index that was calculated using phytoindication data for all studied species habitats made it possible to determine the level of their favor. It has been established that the conditions of forb-grass meadow with bracken in the bracken-herbaceous pine forest provide more optimal ecological parameters for the growth of the species. The least favorable conditions for P. patens s.l. development are formed in cowberry-green moss and herbaceous pine forests, where the maximum discomfort indices are recorded: 1.09 and 1.01, respectively. The studied CPs are characterized by low density and generativity, which demonstrate a reduction trend on a gradient of ecological conditions.

This work is aimed at assessing the dynamics of the composition of soil waters in coniferous forests subjected to air pollution from the Severonikel’ copper-nickel smelter in Murmansk oblast. The objects of investigations are the most common in boreal zone spruce forests with dwarf shrubs + green mosses and pine forests with dwarf shrubs + lichens. The results show a significant intra- (below the crowns and between the crowns) and interbiogeocenotic (spruce and pine forests) variation in the composition of atmospheric deposition and soil waters in forests under pollution. The atmospheric deposition of pollutants and leaching of their compounds from all soil genetic horizons are tens (sulfates) and hundreds (copper and nickel) times higher than in reference sites and their fluxes below the crowns are usually more intense than between the crowns. Long-term dynamics (from 1993 to 2012) demonstrate reliable trends in the reduction of concentrations and leaching of sulfates and heavy metals from the soil. The molar ratio of basic cations to aluminum (BC/Al) in soil waters from all soil horizons does not drop to the level of critical, whereas for mineral nitrogen the lowest critical level (0.2 mg/L) was exceeded in waters from all horizons at all stages of digression. It was shown that, for the early detection of exceedances of the critical level for mineral nitrogen in soil waters, an evaluation of their composition is necessary not only between the crowns, but also below them.