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We studied the communities of soil surface Coleoptera (Carabidae et Tenebrionidae) in the mountain hollows of Altai (Kurai and Chuya) and Tuva (Ulug-Khem and Ubsu-Nur; in the latter, the arid western sector and the more humid eastern sector were studied). Collections were made in the same habitats at intervals of about 60 years: in 1962-1963 and in 2018-2020. Climate changes over this period were analyzed. In general, the climate of the characterized steppe depressions retained the features of sharply continental, with negative mean annual temperatures, moisture deficit and high frequency of fluctuations of all parameters. In all regions an increase in average annual temperatures and in the last 10-20 years an increase in annual precipitation has been observed, most strongly in the Ulug-Khem hollow, creating preconditions for reduction of aridity of ecological conditions. Over 60 years, the number of beetles of the studied taxa has changed several times, sometimes by more than an order of magnitude. At the same time, the number of representatives of the more xerophilic Tenebrionidae family fell, while the number of the more mesophilic Carabidae increased. When comparing the proportion of tenebrionids in the population of different habitats in the 1960s with their proportion in 2018-2020, a sharp, several-fold decrease in their participation in the communities is observed in almost all cases. More beetle species with a more northern or broader (polyzonal and/or transpalaearctic) distribution are becoming more common in the Tuva basins. Such species are found in both humid and arid regions. These changes in species compositions and soil-dwelling beetle communities may reflect mitigating climatic conditions due to some increase in precipitation in the studied region. The mean values of the indices of species diversity and abundance do not differ in general for the “before” and “now” ecosystem states. There are also no reliable differences for total species richness and total abundance. But there are noticeable interannual differences for some diversity indices calculated for Altai ecosystems in 2018 and 2020. This may indicate that differences between the overall diversity indices of ground beetle communities in dry and wet years overlap the long-term trend caused by climate change, and populations of species with different life strategies in the communities respond quickly to these changes without losing the overall structural complexity of the animal population.

Coregonus sardinella Valenciennes in the Khatanga River basin (Taymyr Peninsula) was considered as a component of ichthyocenosis and was never the subject of special study. As well-known published materials show, Coregonus sardinella in the Khatanga River basin are represented by semi-anadromous, lacustrine and lacustrine-river forms. In this work the features of the size and age structure characteristics, fecundity, migration and fishing in modern conditions of the semi-anadromous form of Coregonus sardinella are analyzed. During the study period (2010-2018) fish with a length of 186 to 364 mm and a mass of 54 to 442 g have been spotted in the spawning stock of semi-anadromous Coregonus sardinella in the Khatanga River basin; an average of 275 mm in length and 163 g in weight at the age of 5+ to 15+ years. Males slightly prevailed over females in numbers (57.3 and 42.7 % respectively). The individual absolute fecundity (IAF) has been shown to vary from 4.6 to 36.7 thousand of eggs, on average 13.4 thousand of eggs, during the period 2010-2018. Individual relative fecundity (IRF) varied from 37.5 to 172 pcs/g of body weight, on average 88.4 pcs/g. The boundaries of the main spawning grounds were clarified, which are located on the section of the Kheta River from its mouth to the mouth of the Boganida River (a tributary of the Kheta River, 414 km from the mouth) and the Khatanga River, 20 km from the confluence of the Kheta and Kotuy rivers.

Trematodes of Plagiorchis genus are widespread endoparasites with a life cycle involving several hosts. The present work on the study of the second intermediate hosts of the genus Plagiorchris was carried out in the basin of Chany Lake, located in the forest-steppe of Western Siberia, where pass the migration routes of many species of aquatic and near-water birds - the final hosts of these trematodes. The work was carried out in 2014-2015 in the reed zone of the Fadikha Lake, which is the habitat of the first intermediate hosts of plagiorchids - snails. Representatives of the classes Insecta, Malacostraca, Gastropoda were studied to identify the potential second intermediate hosts of the genus Plagiorchis. In the Chany Lake basin, metacercariae of Plagiorchis genus (P. elegans и P. multiglandularis) were found only in insects from the order Odonata: the largest part of infected were larvae of Sympetrum vulgatum (68 %), followed by species S. flaveolum (18 %), S. sanguineum (9 %) and Aeshna serrata (5 %). The prevalence of metacercariae of the detected trematode species for 4 Odonata species during the study years varied in the range from 3.3 to 45.5 %, the intensity of invasion - from 2 to 4 trematodes per 1 odonate larva. Infection with metacercariae increased with the age of odonate larvae. The tendency of a positive relationship between the infection (prevalence) of the first (snails) and the second (odonate larvae) intermediate hosts was revealed. A reliable relationship has been established between the prevalence of the invasion of odonate larvae and the abundance of their populations, which varies throughout the season. Seasonal changes in the infection of odonates with metacercariae of Plagiorchris genus are associated with the phenology of these insects: periods of increased infection were recorded on the eve of the mass emergence of odonates, when the number of odonate larvae in the reservoir is extremely high, and vice versa, periods of decline in infection were noted after the mass metamorphosis of odonates.

The paper contains original data on the composition and structure of Oligochaeta communities in the zone of influence of wastewater from a pulp and paper industry (the Vychegda River, the Northern Dvina River basin). 40 species and forms of oligochaetes have been identified. We found species having been earlier identified only in tributaries, in floodplain water bodies and in lakes of the Vychegda River basin. By the diversity index (Shannon index (H_N) and Simpson index (D_S)), evenness index (Pielow index (E)), and Whittaker (βw ) indices, the studied section of the river exceeds the control section by the species diversity. There is a significant increase in abundance and biomass of oligochaetes in comparison with section higher up the river. Based on the correlation analysis between the quantitative development indicators of oligochaetes with the environmental parameters (type of substrate, presence of algal growths and macrophyte, depth, chemical composition), the assessment of biotopic confinement of species (F_j) and conjugate between species (r_A), we found out that the distribution of oligochaetes in the study area largely depends on the type of substrate. According to the obtained results on the assessment of diversity and distribution of oligochaetes in the zone of influence of wastewater from a pulp and paper industry, the appearance of technogenic parts with artificial substrate along the shore line leads to changes in the composition, diversity and quantitative development characteristics of benthic organisms.

An analysis of the variability in the development of Scutellaria baicalensis Georgi (Lamiaceae) plants collected from natural habitats (Zabaikalsky Krai, Amur Region, Primorye) and grown under the same culture conditions (Novosibirsk) is given. It has been established that in S. baicalensis, under new growing conditions, interpopulation differences in morphological characteristics and the timing of the onset of phenophases developed in nature are preserved. Data analysis shows the existence of significant differences ( t > 3) between the steppe Zabaykalsky and forest Primorsky cenopolations (CP) in plant height, number of pairs of leaves, number of shoots both in nature and during introduction. The flowering period in the Zabaykalsky CP comes earlier, compared to the Primorsky CP, both in nature and in culture. In Zabaykalsky CP in culture, individuals bloom in early July. In the Primorsky CP, the flowering period begins at the end of July-August, the seed ripening period is extended, especially in the first years of introduction. The formation of steppe Zabaykalsky and forest Primorsky ecotypes can be assumed.

The article presents the results of the analysis of the peculiarities of renewal of woody vegetation after a crown fire which broke out in 2010 in the beech-yew forest in the Termenlik district (965 m a. s. l.) on the south-eastern slope of Gimrinskiy Khrebet in the Foothill Dagestan (East Caucasus). For the description of the changes which occurred on the post-fire spot in 2019 there have been arranged eight sample areas (SA) 100 square metres each (10 × 10 m). A geobotanical description of the sample area has been conducted according to the generally accepted method which included the definition of the microrelief, the species composition (species richness) of the trees, their distribution in the layers and biometric parameters. For each treespecies there has been revealed a projective cover in percentage as well as the abundance, the sequence of penetration and distribution, the dynamics of the development of the above-ground part and there have been evaluated the results of their competitive interaction. Owing to the appearance of new species of seed origin with accelerated growth in the composition of the forest stand, such as Populus tremula L., Salix caprea L., Acer campestre L., Fraxinus excelsior L., a suggestion has been made about the change of the succession trend and the formation of a new reformed cenosis without participation of the basic dominant species of the primary forest, namely Fagus orientalis Lipsky., Carpinus caucasica L., Taxus baccata L., Acer platanoides L. There has been offered a method of mechanical removal of the dominant species P. tremula leading to the enhancement of the competitive advantages of the pioneer species characteristic of this locality. It is believed that such a method will lead to an increase in the competitive advantages of other species with a predictable consequence. Thus, in the studied community of the burned area, vegetation development will change towards the initial beech-yew forest for this area, and not a community dominated by aspen.

The paper summarizes the results of field studies of carbon dioxide and methane fluxes in peatland ecosystems on the territory of license areas of the Salym group of oil fields (Khanty-Mansi Autonomous Okrug). The largest fluxes of carbon dioxide and methane are observed in mesotrophic and eutrophic bogs, which are characterized by the maximum of biomass storages. Significant negative CO₂ fluxes (-1161.6 mg CO₂ m^-2∙h^-1) associated with photosynthesis have been recorded here, but they also have a high emission component of carbon exchange (ecosystem respiration) (more than 680 mg CO₂ m^-2∙h^-1). Methane emission reaches 23.9 mg CH₄ m^-2∙h^-1. In oligotrophic bogs, in the daytime, fluxes of СО₂ in range from -400 to -600 mg CO₂ m^-2∙h^-1 were recorded, and at night from + 160 to +840 mg CO₂ m^-2∙h^-1. Methane fluxes from hummocks in oligotrophic bog complexes were up to 1.1 mg CH₄ m^-2∙h^-1, and from decreases 3.9 mg CH₄ m^-2∙h^-1 from hollows. Large carbon dioxide and methane fluxes were registered from the surface of clear-cuts at a pine-dwarf-shrub-sphagnum bog, where, depending on the ground cover, the release of CO₂ can be from +46 to +480 mg CO₂ m^-2∙h^-1, and emission of CH₄ - up to 4.6 mg CH₄ m^-2∙h^-1.

According to the results of studies of the Vasyugan River in July 2019 and 2021 the species composition, taxonomic structure, dominant complex, abundance and biomass, indices of phytoplankton biodiversity were established for the first time. 166 species and intraspecific taxa of algae from 8 divisions have been identified, green algae (Chlorophyta division) form the basis of species richness. The dominant phytoplankton complex includes centric diatoms, green algae and non-heterocyst cyanoprokaryotes. Biodiversity indices indicate high species richness, close to average complexity and evenness of the phytoplanktocenosis structure. The trophic status of the river corresponds to the eutrophic category of waters, the water quality ranges from class 3 “satisfactory purity” to class 4 “polluted”.

The authors propose and analyze the method of soft rock reinforcement by injection of bicomponent organomineral resin with compressed-air blowing of reagents deeper in rocks. The bench tester structure, the polymeric formula, the composition and resin properties, as well as the treatment procedure are presented. The tests are described. The scope of the discussion encompasses the results of the permeation tests, strength tests and the analysis of structure of voids in sand samples after their stabilization using the proposed approach and the standard single-component resin injection. The advantages of the successive injection include the chemical treatment coverage, specific consumption of agents and the increased strength.

The authors discuss the known methods of shaft lining monitoring and put forward a new technique of real-time measurement of displacements on inner surface of concrete lining by laser scanning. The results of the preliminary filtering and subsequent processing of the specific monitoring measurements implemented in two mine shafts of Uralkali are presented as the estimates of the change in the shaft diameter, circumferencial strains and ellipticity. The monitoring data are effectively applicable in verification of mathematical models of strains and strength of concrete lining in shafts, including their junctions with horizontal tunnels.