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The properties of a sandy Ferric Podzol over fluvioglacial deposits and the root mass of its 0-20 cm layer with Pinus sylvestris L. fine roots (≤ 3 mm in diameter) were studied in a mid-taiga cowberry-type pine stand. Keeping in mind the structure of the phytogenic field of a tree, the study was subdivided into the “trunk”, “crown”, and “gap” zones. The root mass of the forest floor and the mineral horizons was found to change in different directions in the said zones. In the forest floor, the “trunk” zone was more saturated with roots than the “gap” zone, while the trend in the soil mineral layer was the opposite. The highest root biomass was associated with sites that were the richest in soil nutrients and organic matter (NPKC). The cellulolytic activity and eco-physiological parameters of the microbiota varied in the studied horizons. Cellulolytic activity in the forest floor was the highest near tree trunks, while the spatial variation of this parameter in the mineral body of the soil was less pronounced. A correlation was detected between the contribution of root respiration to total СО₂ emissions from the soil surface and the biomass of fine roots (≤3 mm) in the 0-20-cm soil layer. The effect of the soil thermal regime on root mass in different zones of the phytogenic field was studied. Soil temperature variation due to the redistribution of solar energy by the canopy results in a higher root mass in areas receiving more heat. The zone with better heated soils is the canopy gaps. The effect of the temperature of the soil’s root mass is more explicit in the mineral layer. The results of this study can be used in environmental monitoring and in predictive assessments of the effects of climate change on boreal forest ecosystems.

The abundance, biomass, and size-morphological structure of heterotrophic bacterioplankton were determined in freshwater environments of the Svalbard archipelago (Norway), differing in morphometry and trophic level. The quantitative parameters of bacterioplankton varied within wide limits and increased along the trophic gradient of the waters. Medium-sized cocci and coccobacilli reached up to one third of the total abundance and a half of the total biomass of bacterioplankton. The abundance and biomass of small cocci varied over a wide range, while small rods were, on the contrary, relatively stable in these parameters. With an increase in trophic status, the proportion of small cocci in the community increased, while the proportion of rods and vibrios decreased. The proportion of medium-sized cocci and coccobacilli changed less, although there was a tendency for its increase in the trophic gradient.

Aquatic vascular plants at different stages of their life cycle exhibit different physiological and metabolic activity, resulting in changing habitat conditions for hydrobionts. The hydrochemical parameters of the environment, the concentrations of phytoplankton pigments, the abundance of bacteria and zooplankton were studied in experimental ecosystems (microcosms), including actively vegetating and completing the vegetation of aquatic plants. In microcosms with actively vegetating hornwort Ceratophyllum demersum L. the concentration of P_tot, Mg²⁺ and BOD ₅ increased, and Na⁺ and Ca²⁺ decreased. In systems with a dying arrowhead Sagittaria sagittifolia L. the concentration of K⁺ increased to the greatest extent, P_tot, Cl^-, and BOD₅ to a lesser extent, and the concentrations of SO₄^2- and O₂ dissolved in water decreased. In the presence of plants, higher concentrations of phytoplankton pigments were observed in comparison with the control. The quantitative indicators of bacterioplankton did not differ. The number and biomass of zooplankton in general and the dominant species Daphnia longispina in microcosms with plants exceeded these indicators in the control. The hornwort, which lost half of the biomass, but continued vegetation, had a stronger stimulating effect on the abundance of zooplankton than the arrowhead, which finished vegetation.

This article presents the results of the transformation of natural ecosystems due to an emergency diesel fuel spill at CHPP-3 in the Norilsk Industrial District. Oil products have negatively affected the vegetation of the floodplains of the Bezymyanny and Daldykan creeks and Ambarnaya River. Some of the plant communities have been significantly transformed due to direct contact with diesel fuel, which is expressed in a noticeable decrease in the indices of alpha, beta, and gamma diversity. The vegetation of the lower reaches of the Ambarnaya River is the most polluted. No effect of oil products has been recorded in the floodplain of the Pyasina River. Here, the indices of phytodiversity of conditionally disturbed communities are comparable to those of background vegetation. All bryophytes and some species of vascular plants of dry and drained habitats are extremely nonresistant to oil pollution. Conversely, aquatic and streamside-aquatic species of perennial long- and short-rhizome grasses are resistant to pollution. The diversity of vegetation affected by oil products is represented by five associations and three subassociations of three classes of floristic-sociological classification. We describe three associations ( Chamaenerio latifolii - Sanguisorbetum officinalis ass. nova, Eleocharo acicularis - Arctophiletum fulvae ass. nova, and Equiseto arvensis - Salicetum dasycladi ass. nova) and three subassociations ( Chamaenerio latifolii - Sanguisorbetum officinalis typicum subass. nova, Chamaenerio latifolii - Sanguisorbetum officinalis angelicetosum decurrentis subass. nova, and Caricetum aquatilis cerastietosum jenisejensis subass. nova) for the first time.

On the territory of South Kazakhstan (Almaty region) there are old abandoned warehouses with prohibited and unused pesticides, the active substances and metabolites of which pollute natural water sources and pastures of farm animals located nearby. The analysis of blood samples of 50 heads of cattle from five monitoring points of the Almaty region was carried out for the presence of micronucleus in erythrocytes, genomic mutations and chromosomal aberrations in lymphocytes. Cell cultivation and preparation of preparations were carried out by standard cytogenetic methods. The frequency of erythrocytes with micronucleus in cattle kept in experimental plots was 3.3 %, which is 4.7 times higher than in the control group. The incidence of genomic mutations in the blood system of experimental groups of animals exceeded the same indicator in the control group by an average of 1.6 times, and chromosomal aberrations - by 9.1 times. The proportion of hypodiploid cells was 46 % of the total number of genomic mutations. Polyploidy accounted for up to 17 %, and hyperdiploidy was found in 5 % of cells. Analysis of individual indicators of general cytogenetic instability in the blood system of animals showed that hyperdiploidy and chromosomal aberrations are the main components of this indicator, which, on average for five monitoring sites, exceeded the control data by 7.9 times. Statistical data processing allows us to make a conclusion about the genotoxic effect of prohibited and unused pesticides on the body of cattle, which have clastogenic, aneugene and mutagenic effects even after 30 years.

Introduced woody plants are widespread in the green spaces of Siberia, the mycobiota of which is formed on the basis of widespread local species. As a result of studying the biota of fungi associated with Populus balsamifera L., Acer negundo L., Ulmus pumila L., Prunus maackii Rupr. and Tilia cordata Mill. 105 species of mainly agaricoid macromycetes, common for Siberia, were identified and characterized mainly by a wide trophic and topical specialization. Many of them are characterized as synanthropic organisms. The largest number of macromycete species is generally associated with A. negundo (61), the smallest with U. pumila (16 species). The mycobiota of all tree species, except for T. cordata , is dominated by wood-destroying species. More than half of the identified wood-destroying fungi are capable of parasitism, and in the green plantations of Krasnoyarsk they form fruit bodies more often on living tree introduced species, while outside the city on aboriginal tree species, fruiting of these mushrooms begins only after the tree dies. The largest number of wood destroyers was found on A. negundo (39), among which Flammulina velutipes (Curtis) Singer dominate. and Bjerkandera adusta (Willd.) P. Karst. With a relatively rich biota of ground macromycetes associated with A. negundo (22 species) and T. cordata (17 species), there is a significant difference in the ratio of its constituent ecological-trophic groups: soil and litter saprotrophs are mainly associated with the first tree species (dominated by representatives of families Agaricaceae , Marasmiaceae and Psathyrellaceae ), with the second - mycorrhiza formers (dominated by Inocybe spp ., Inocybaceae ). In general, among the macromycetes of green spaces formed by introduced tree species, the mycobiota of U. pumila and P. maackii is distinguished by the least taxonomic and ecological-trophic diversity.

The paper presents a review of the methods of experimental investigations of the Görtler vortices in boundary layers. The proposed models are used in experiments for the analysis of the Görtler instability; the major methods of Görtler vortex generation are described. It has been revealed that spontaneous uncontrolled emergence of the Görtler vortices is caused by the roughness of model surfaces (especially in the area of the leading edge of a plane model) and free-stream disturbances. Effective methods of introduction of controlled stationary and nonstationary disturbances generating the Görtler vortices in the boundary layer are described. The methods of experimental measurements of boundary layer parameters in the presence of the Görtler vortices are presented; the diagnostic capabilities of these methods are demonstrated, and the major scientific results obtained by these methods are reported.

A numerical model of the dynamics of a flat localized region of turbulent perturbations of non-zero buoyancy in a linearly stratified medium has been developed on the basis of the mathematical model, including differential equations for Reynolds stresses transfer and algebraic model of a vector of turbulent scalar flux. The evolution of a heated turbulent spot has been considered. The non-zero buoyancy is the reason of an increase in the geometrical size of the turbulent spot and generation of internal waves of greater amplitude. The generation of the total energy of turbulence is insignificant even in the case when the initial potential energy of a turbulent spot of non-zero buoyancy is comparable to the initial total energy of turbulence in it.

The present study shows that enhancement of mixing efficiency (increasing the total pressure of the mixture) requires expansion of the cross section of the high-pressure gas flow. It is found that the parameters of the mixtures are identical in the cases of distributed and one-step mixing of the perfect gas flows. However, distributed mixing (multistep mixing as a finite-dimensional analog) is more reasonable because it ensures flow control to provide conditions to satisfy the existence of a steady flow in the channel.

The present study shows that enhancement of mixing efficiency (increasing the total pressure of the mixture) requires expansion of the cross section of the high-pressure gas flow. It is found that the parameters of the mixtures are identical in the cases of distributed and one-step mixing of the perfect gas flows. However, distributed mixing (multistep mixing as a finite-dimensional analog) is more reasonable because it ensures flow control to provide conditions to satisfy the existence of a steady flow in the channel.