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The morphological and physiological biochemical features of calciphytes Hedysarum grandiflorum Pall. and Hedysarum gmelinii Ledeb are investigated. Plants H . gmelinii grown on a more moisturized and saline soil substrate. The leaf parameters of plants H . grandiflorum were characterized by a greater thickness, an area and contained significantly more water compared to the leaves of H . gmelinii . The leaf mass per unit area of H . gmelinii is 1.5 times higher than that of H . grandiflorum . Pigment foundation of H . grandiflorum is more enriched with chlorophylls. The level of lipid peroxidation in H . grandiflorum plant cells lower more than twice compare with H . gmelinii . The activity of enzymes catalase, peroxidase, polyphenolxidase on the contrary it was higher in H . grandiflorum . In addition, H . grandiflorum leaf lipids were distinguished by a greater saturation of fatty acids (SFA) (46.0 % of the amount of SFA) than H . gmelinii (31.5 %), but the concentration of α-linolenic acid in the leaves of H . gmelinii 1.5 times higher than H . grandiflorum . It was concluded that the existence of calciphyte plants in peculiar soil-climatic conditions imposes specific morphological and physiological and biochemical features even among closely related species H . grandiflorum and H . gmelinii .

The results of a seven-year study of two populations of the rare orchid Cypripedium calceolus L. located in different ecotopes (in the forest and in the swamp) on the territory of the Komi Republic are presented. It was revealed that the size of the shoots of this species is influenced by the weather conditions of both the current and previous growing seasons, while the specifics of the action of weather factors depending on the growing conditions are noted. The number of generative shoots in the studied populations is positively associated with the temperature and humidity of August of the previous growing season, and frosts have an additional effect on their number. The number of shoots in different growing conditions during the study period changed synchronously and was positively associated (as well as the number of juvenile plants) with the weather (temperature and precipitation) at the beginning of the growing season. At the same time, the population of C. calceolus , growing in different ecotopes, differed in a number of characteristics: the spatial placement of shoots, their size, the number of flowers per shoot, etc. This indicates that all population parameters are strongly influenced by the local conditions of the site. In a more shaded habitat (forest), the population of C. calceolus remained stable during the seven years of study, whereas in the swamp the population was more dynamic. There was an increase in its number and active seed renewal. Despite the different seed productivity of the fruit in the two populations, the actual seed productivity of the generative shoot was the same in the same years of research.

The assessment and reliable prediction of the productivity of grassland communities are largely determined by the approaches and methods used. The use of information on the species composition of the plant community and its functional structure in determining the primary production expands the possibilities of using modern information databases of geobotanical data. Selection of practically significant functional groups of species (graminoids, motley grasses, legumes) in composition of grassland communities of hayfields and pastures and determination of dominant species allows to include indicators of biodiversity in the procedure of agricultural lands productivity estimation. The experience in predicting the amount of aboveground phytomass of grassland ecosystems using the data on the functional composition and projective cover of species is discussed. The conducted cluster analysis confirms the assumption of the relationship between community biodiversity and its productivity. Based on the main provisions of the dominance hypothesis, by building a statistical linear model, the possibility of predicting the value of aboveground biomass from the data on the species composition of communities and the abundance of the dominant functional groups of plants, which act as universal evaluation criteria, was tested. The predictive statistical model is constructed on the basis of processing of the experimental data received from 32 sample geobotanical areas. The model shows the relationship between the value of the predicted biomass for the community and the abundance of the main functional groups of plants, the way they are used and the result of assigning community to the classification categories of the EVC and EUNIS systems. The applied classifications, based on species lists and indicators of the projective cover of species, bring a component of biodiversity in the further evaluation of community productivity. The use of the developed linear regression model makes it possible to estimate the productivity of grassland communities similar in species composition and belonging to the same classification categories with a sufficiently high degree of reliability without direct collection of data on the produced biomass. The model makes it possible to take into account the contribution of plant species composition to the provision of productive ecosystem services, providing the development of an accessible technique for their evaluation.

According to the results of bird counts carried out in 140 habitats over 12 years, in the period from 1982 to 2002 drawn up hierarchical classification and a structural graph of the similarity of ornithocomplexes in the plain southwestern part of Western Siberia and Northern Kazakhstan have been compiled. The hierarchical classification contains 10 types of bird populations. The similarity graph is built at the level of types and is represented by three rows (trends). One row consists of bird complexes of residential and recreational areas, the second from wetlands and the third from forest, forest-field and steppe habitats. The given characteristics of taxa of classifications contain information on the three most numerous bird species (leaders in abundance), their share in the community, population density, and also on the background species richness. Based on the assessment of the degree of coincidence of the similarity of bird communities and environmental factors, a hierarchy of the impact of the main anthropogenic and natural factors determining the formation of the bird population has been established.

N the northern spurs of the Manchurian-Korean Mountains (Primorsky Territory), an assembly of dung beetles from sheep dung was studied. Data on the species composition, population dynamics, number and biomass of dung beetles are presented. Comparison of assemblages of dung beetles of the inhabitants of sheep dung of the northern spurs of the Manchurian-Korean Mountains and the South Sikhote-Alin Mountains shows that despite the fact that both groups were formed on the base of one local fauna and have the same number of species, but the taxonomic structure and dynamic (seasonal) aspects are quite different. Differences in the species composition and composition of trophodynamic groups are due to the peculiarities of the geographic location, different weather and climatic conditions, grazing regime and differences in the composition of grazed animals, historical factors of the formation and dynamics of beetle assemblages. Weather conditions, as a factor influencing the rehydration of sheep droppings, determines the dynamic processes in assemblages and limits the penetration of certain species into the Sikhote-Alin Mountain system. A small size of sheep excrements, which are both trophic and topical resources, determines a high transformation rate of the substrate and the distribution of species according to a hypothesis of niche interception. The overlapping of niches in species from the same trophodynamic groups leads to a shift in the timing of the imaginal activity of certain species

We present the results of study on the number of indicator bacterial groups of the nitrogen cycle in plankton and epilithon of the littoral zone Lake Baikal in the spring and autumn periods from 2017 to 2019. The number of ammonifying bacteria (AB) in the lake waters varied from 25 to 6.0 × 10⁵ cells/ml; in epilithic biofilms - from 3.5 × 10³ to 9.5 × 10⁶ cells/cm². The stations subject to anthropogenic impact showed a high number of AB as evidence of active mineralization of nitrogen-containing organic compounds. The maximum number of AB in the water column and the biofilms from stony substrates was detected in June 2017 in the water area of the Severobaikalsk town. The average annual number of AB in the water column was (5.0 ± 2.8) × 10² cells/ml in June and (6.0 ± 1.3) × 10² cells/ml in September. In epilithic biofilms, it was an order of magnitude lower in June than in September, (3.4 ± 1.2) × 10⁴ cells/cm² and (2.6 ± 1.4) × 10⁵ cells/cm², respectively. The number of denitrifying bacteria (DB) in water varied from 0 to 60 cells/ml; in epilithic biofilms - from 6 to 2.5 × 10³ cells/cm². Throughout the study period, the highest number of DB in epilithon was detected in June at the station near Elokhin Cape. The average annual number of DB in the water column was 13 ± 4 cells/ml in June and 7 ± 6 cells/ml in September; in epilithic biofilms - (7.9 ± 2.4) × 10² cells/cm² in June and (4.8 ± 0.5) × 10² cells/cm² in September. The number of planktonic AMB positively correlates with the concentration of ammonium ions; the number of DB directly depends on the nitrate concentration and inversely depends on nitrites at some stations.

To reveal changes in plant mineral nutrition causing leaves’ chlorosis and parthenocarpy in the blue honeysuckle plants of Siberian origin, grown on plantations in Heilongjiang Province, China, we compared macro- and trace elements’ composition in two counties in China and two districts in the south of the West Siberian plain. It was found that massive leaves’ chlorosis and dying-off, as well as hormonal changes resulting in parthenocarpal fruits, may be associated with soil acidity (рН_KCl 4.0-4.5) on some of the study sites in the Heilongjiang Province, as such high acidity increased plant available Al, Fe and Mn concentrations to phytotoxic levels. The blue honeysuckle plants grown on such study sites had specific patterns of Al, Fe, Mn, Cu and Zn distribution throughout their organs, as well as accumulation of toxic concentrations of Al, Fe, Mn in leaves, resulting in aberrant P/Al, Ca/Al, Mg/Al, P/Fe, P/Mn, Cu/Fe and Cu/Mn ratios, which are vitally important for plants.

Results of studying kerosene combustion in a pseudoshock with varied temperature and velocity at the scramjet combustor model are presented. Thermodynamic estimates show that either a supersonic or transonic flow can be retained over the combustor duct at parameters corresponding to the Mach number at the engine entrance М₀ » 4.5. The possibility of the pseudoshock regime in the constant-section part of the combustor is experimentally studied in the case where the Mach number behind the inlet (at the combustor entrance) is М _c > 1. Conditions of initiation and evolution of this combustion mode under a pulsed-periodic action on the flow are determined.

The Hedvall effect was implemented in self-propagating high-temperature synthesis (SHS) in two low-energy compositions TiNi + 1.1C and Ni₃Al + 1.2Si using preliminary mechanical activation (MA) in an energy-intensive planetary ball mill. The dependences of the initiation temperature and the maximum reaction temperature on the MA time were obtained. The MA modes providing the solid-state mode of the self-propagating reaction were determined. The results of X-ray phase and electron microscopic examination of MA and SHS products are given.

A technique for obtaining large burning monolithic titanium particles is described. The combustion of particles with a diameter of 120 ÷ 540 mm in free fall in air at atmospheric pressure is investigated. The burning time and the characteristic time of the beginning and end of fragmentation as a function of particle diameter are determined by processing video recordings of combustion of more than 250 particles. Two fragmentation modes are described. It is found that their occurrence depends on the diameter of the burning particle. The boundary particle size separating the modes is determined. It is shown that the fragmentation regularities and characteristic times for titanium agglomerates and monolithic particles of the indicated sizes differ slightly.