Home – Home – Jornals – Contemporary Problems of Ecology 2026 number 1

We report results of geostructural, mineralogical, petrographic, geochemical and geochronological (⁴⁰Ar/³⁹Ar) investigations of ophiolites from the northern and southeastern fragments of the Tatarka-Ishimba suture zone of the Yenisei Ridge combined into the Rybnaya-Panimba belt. The ophiolites consist of massive and pillow-lava metabasalt, massive and layered metagabbro and metadolerite, and represent fragments of the upper part of the oceanic crust. They formed in a mid-ocean ridge or marginal sea setting from depleted mantle sources corresponding to components of the N-MORB and E-MORB geochemical types. We propose a model for the tectonic history of emplacement of the ophiolites in the Meso-Neoproterozoic time. At the Meso-Neoproterozoic boundary (Stenian-Tonian), 1051-916 Ma, a thrust system was formed and the oceanic crust fragments (ophiolites) were accreted to the passive margin of the Central Angara terrane (microcontinent). The subsequent convergence and collision of this microcontinent with the Siberian Craton (786-749 Ma) caused the formation of strike-slip/thrust deformation in the rocks of the Tatarka-Ishimba suture zone including the ophiolites. In the Cryogenian time (708-700 Ma), strike-slip and reverse fault deformations occurred in these rocks due to a new episode of tectonic activity caused by the transition between convergent settings - end of the collision and start of the active continental margin.

We analyzed composition of monzonite-syenite intrusive rocks within the Bilikan-Khulamri magmatic zone of the central segment of the Yana-Kolyma Orogenic Belt. These rocks compose small intrusions cutting terrigenous strata of the Inyali-Debin turbidite terrane. The monzonitoids under consideration contain moderate amount of silica and Al₂O₃, relatively high contents of K₂O, Na₂O, MgO; by chemical composition they are similar to latite and very close to alkaline-salic intrusive rocks of the Aldan Igneous Province. Concentrations of major and rare elements indicate that these rocks belong to granitoids of convergent continental margins, including syncollisional and those of volcanic arcs. According to U-Pb dating (SIMS), the age of zircon from quartz syenite is 84.0 Ma. It corresponds to the secondary pulse of magmatic activity of the Okhotsk-Chukotka Volcanic Belt. The specific chemical composition of the monzonitoids close to the shoshonite-latite series is due to their location deep in the back arc of the volcanic belt, at more than 200 km from its axial zone, on the sialic bedrock composed by turbidite terrigenous complexes.

This paper deals with new geological, mineralogical, isotopic-geochemical (major, trace, and rare earth elements, Sm-Nd isotopic data) characteristics of the unique Kalevian (1926-1923 Ma) komatiite-tholeiitic magmatic manifestation for the first time identified in the supracrustal Kaskama Formation from the Inari terrane of the Kola-Norwegian region Fennoscandian Shield. In the massive and porphyritic komatiites, the primary (magmatic) mineral paragenesis represented by olivine 20-40%, orthopyroxene up to 5%, hornblende up to 10%, clinopyroxene 20-40% and plagioclase 20-30% was identified. Liquidus temperatures for olivine and pyroxenes calculated in the COMAGMAT3.73 software suite are in the range of ~ 1500-1200 °C. The komatiites of the Kaskama Formation belong to the Al-nondepleted type and are characterized by low REE _N content (1-2 relative to C1 chondrite), a total concentration ∑REE_avr = 0.15-0.36 ppm, and an unfractionated distribution of REEs, which is a consequence of the generation and evolution of their primary melts outside the field of thermodynamic conditions of garnet stability. The Zr-Y-Nb and Sm-Nd isotopic systematics of the rocks of the komatiite-tholeiitic association indicates the origin of their high-temperature primary melts from a plume source in depleted mantle (ε_Nd( T ) = +3.2 ± 0.3), which is different from the mantle sources of the Jatulian-Ludicovian picrite-komatiite association of the Central Lapland greenstone belt of Finland and the Pechenga intracratonic structure. Considering the amphibolite facies metamorphic conditions of the Kaskama Formation, it can be assumed that the komatiite-tholeiitic association is a deeply eroded (at least 10 km) section of a supracrustal volcan.

The metamorphic rocks in the northeastern Taimyr region are a consequential result of its complex geologic history. Series of metamorphic processes were associated with the formation of lode copper and noble-metal mineralization. The aim of this study is to investigate the type and degree of metamorphism of the host basic volcanic rocks in the ore cluster. We have identified three stages of metamorphic process: The first stage led to the formation of actinolite and sodium plagioclase paragenesis (with its chemical compositions corresponding to temperature of about 400 °C); the second stage resulted in the crystallization of hornblende, plagioclase, spessartine-almandine garnet, biotite, feldspars (oligoclase-andesine and K-Ba types), and various Fe-Ti phases (mineral geothermometers show the highest temperature range of 450-600 °C), and the final stage produced clinochlore, pyrite, and fluorapatite (330-290 °C according to the Al^IV contents in chlorite). We interpret the studied rocks as hornfels based on the highly discordant contours of the metamorphic aureole, the compositions of garnet (spessartine is a predominant component), and the K-Ar ages of biotite (253 ± 5 Ma) and plagioclase (239 ± 8 Ma), which coincide with the time of late Paleozoic-Mesozoic postcollisional granitoid magmatism. The absence of schistosity, the disequilibrium assemblages, and the abundance of volatile-rich minerals (containing F^-, OH^-, and SO₄^2-) also indicate their contact origin. The discovered aureole includes the known Cu-Au-Ag veins and metasomatic occurrences, the age of which is therefore late- or postmetamorphic. We confirm the earlier hypothesis of our colleagues about the impact of a concealed granite massif on the host rocks and consider the high metamorphic grade to be a natural boundary for the ore cluster.

The behavior of Ag in the oxidation zone of the Kyzyk-Chadr gold-sulfide-quartz deposit (Tuva Republic, Russia) is investigated. The primary focus is on the mechanisms of Ag differentiation under supergene conditions, including the formation of secondary minerals and silver incorporation as an isomorphic impurity into other phases. It was established that Ag in the oxidation zone forms chalcogenides (acanthite, petrovskaite, uytenbogaardtite, and jalpaite) and halides (iodargyrite, bromargyrite, and mayersite), which are associated with malachite, chrysocolla, brochantite, quartz, and iron hydroxides. Electron probe microanalysis reveals Ag concentrations in secondary copper sulfides (covellite, chalcocite, yarrowite, etc.) of ≤0.7 wt.%. Optimization of the microanalysis parameters to enhance resolution lowers the detection limit, enabling the determination of low Ag contents in chalcopyrite (≤0.05 wt.%) and bornite (≤0.09 wt.%). The sources of Ag are primary Ag tellurides and selenides, as well as primary and secondary Cu sulfides that decompose during the oxidation. Computer thermodynamic modeling is used to describe the behavior of Fe, Cu, and Ag during the progressive oxidation of primary assemblages (bornite, chalcopyrite, and acanthite). The Eh-pH conditions controlling mineral migration and reprecipitation are calculated, and the element concentrations required for the formation of secondary phases were estimated.

We report results on the age estimates of the Paleogene diatom datums derived from the magnetostratigraphy at the marine Cenozoic stratigraphic section of the Kvachina Bay, West Kamchatka. Based on a direct correlation with the Geomagnetic Polarity Time Scale, it was possible to determine the age of such levels in the interval between Subchron C13r (35.10-33.73 Ma) and Subchron C9r (27.86-27.44 Ma). Of greatest interest are the dates of the first and last occurrences of Lisitzinia ornata (27.71 Ma and 27.54 Ma respectively), and the first occurrence of Rocella gelida (27.49 Ma). This is the first experience of absolute age estimates of Oligocene diatom biohorizons based on magnetostratigraphy not only in Kamchatka sections, but in the North Pacific region in general. A comparison was made between the obtained age estimates and those published in the literature based on the study of deep-sea cores in various regions of the World Ocean.

We have estimated the proportion of sorbed water converted to ice and hydrate during the interaction of wet sand samples with methane by using the nuclear magnetic resonance (NMR) relaxometry method. There is a thin film of strongly bound water in small pores at the rock-fluid interface. This water does not freeze at the subzero temperatures achieved during the experiment; its amount remains constant without regard to the water content in a sample. We have calculated the amounts of strongly bound water and water converted to ice and hydrate for all samples. Based on the established hydrate stoichiometry, we have calculated the amount of methane converted to hydrate. Analysis of the obtained data has revealed the optimal water content in a sample, which results in the greatest amount of hydrate formation.

The unique relationship between induced polarization parameters and the structure of interface and pore space in rocks sustains considerable interest in applied science, driving the continuously expanding range of application of this method. The physicochemical theory of induced polarization in rocks contains significant gaps, which stem from the complexity of the processes generating secondary electric fields within rocks. To date, laboratory investigation results remain the primary source of new knowledge about the mechanisms and processes occurring in rocks under the influence of an electric field. Over the past decade, several new hypotheses, mechanisms, and models of induced polarization in rocks containing electron-conducting mineral inclusions have been proposed; their key features are described in our article. These hypotheses are actively discussed and used for interpreting induced polarization data obtained in laboratory studies and field tests. We present the results of an experimental study of induced polarization at the shungite - pore moisture interface, conducted on a synthetic capillary model of rocks containing an electron-conducting mineral inclusion. Based on voltammetric measurements, the principal characteristics of shungite polarization in an aqueous NaCl solution are established. The magnitude of exchange currents, the dynamics of interfacial polarization at different current densities, and the features of interfacial potential relaxation are estimated. Our study features the first presentation of measurements of electric currents flowing within the model and inside the shungite inclusion - the induced polarization currents. It is proven that the relaxation of the electric field in the model and that of the induced polarization currents exhibit identical dependences. The proportionality between the polarization intensity of the shungite inclusion and the normal current component at the shungite - pore moisture interface is experimentally confirmed. The resulting materials point to the dominant role of the electrode polarization mechanism for electron-conducting mineral inclusions in rocks. A description of the most probable induced polarization mechanism at the mineral inclusion - pore moisture interface in rocks is provided.

This study demonstrates the practical feasibility of high-precision in-flight measurement of magnetic fields from remote radio transmitters, including the use of unmanned aerial vehicles. The proposed method is based on calculating the Euclidean norm of the full complex magnetic field vector, which eliminates any dependence of the result on the orientation of the measurement system. To compensate for primary field instability, normalization is performed using a synchronized signal from a stationary base receiver. Further accuracy is achieved through pre-flight sensor calibration and spatial data smoothing during processing. Test measurements demonstrate good result reproducibility, with a discrepancy of less than 0.5% of the signal level. Moreover, magnetic field anomaly maps obtained at different altitudes show strong correlation both with each other and with archival data from ground-based inductive electromagnetic surveys.

The paper examines why voluminous felsic magmas formed during subduction initiation in the Tannuola-Khamsara island-arc system (Tuva, Central Asia), focusing on the Ondum subzone. We report geochemical, Sm-Nd and U-Pb zircon data for plagiorhyolites-plagiodacites, andesibasalts-andesites-dacites, their intrusive equivalents (plagiogranites-tonalites and quartz diorites-diorites), and gabbroic inclusions. Two geochemical types are recognized: depleted Type I (dominant; ε_Nd(t)=+10.4…+6.4, (La/Yb)_N=0.3–0.9) and moderately depleted Type II (subordinate; ε_Nd(t)=+7.7, (La/Yb)_N=1.0–1.7). Type I felsic rocks are consistent with low-pressure, water-saturated partial melting of a gabbroic source, whereas Type II reflects lower degrees of melting and/or weaker fluid input. SSZ ophiolites (580–569 Ma) occur in the forearc, arc and back-arc domains, implying near-synchronous SSZ crust formation at subduction initiation. Xenogenic zircon (571–663 Ma) and metamorphic blocks suggest involvement and partial preservation of an inherited oceanic substrate, possibly with an unusually thick terrigenous-carbonate sedimentary cover. We model spatially heterogeneous SSZ extension: new crust formed in spreading sectors, whereas non-spreading segments retained pre-subduction blocks where hydration and anatexis of gabbroic basement (potentially aided by deep seawater-driven hydrothermal circulation along faults) produced large volumes of felsic melts. Local slab melting is recorded by an adakitic tonalite (556±3 Ma, ε_Nd(t)=+1.0), consistent with a terrigenous sediment component carrying an evolved crustal isotopic signature.

a:2:{s:4:"TEXT";s:1439:"The research develops the classical concept of the skin factor proposed by M.F. Hawkins [Hawkins, 1956]. We demonstrate a fundamental limitation of the Hawkins model, in which the permeability of the drilling mud filtrate invaded zone is assumed to be constant (

An ecological explanation is proposed for the prevalence of eicosapentaenoic acid (20:5n-3, EPA) in the lipids of primary producers in aquatic ecosystems, such as diatoms, and of alpha-linolenic acid (18:3n-3, ALA) in the lipids of primary producers in terrestrial ecosystems, specifically seed plants. Photosynthetic membranes are unique due to the presence of conical non-bilayer lipids, monogalactosyldiacylglycerols (MGDG), which are absent in both other plant cell membranes and animal cell membranes. The non-bilayer properties - specifically, the ability to form an inverted conical shape - of MGDG molecules are conferred by the acyl chains of polyunsaturated fatty acids (PUFA). When saturated chains are present, these molecules transform into regular cylindrical bilayer lipids. As structural lipids, MGDG determine essential physical and chemical properties of membranes, often collectively referred to as “fluidity”. These properties include molecular rotation rate, diffusion, permeability, free volume, packing defects, lateral pressure, and curvature stress, all of which influence the effectiveness of membrane protein function. The primary ecological feature of diatoms and other marine and freshwater algae of the “red” evolutionary line, which distinguishes them from green plants, is their ability to photosynthesise under rapid changes in light intensity. This occurs both during their circulation in the mixed surface layer of the water column and throughout the tidal cycle in the littoral zone. The common strategies for light adaptation in green plants - such as changes in chloroplast morphology and alterations in the number and structure of light-harvesting complexes and their antennae - are too slow for these dynamic conditions. Instead, light adaptation in diatoms is achieved through the rapid operation of the xanthophyll cycle (XC) and non-photochemical quenching. These processes occur several times faster than their counterparts in members of the “green” evolutionary line. The presence of a sufficient amount of conical non-bilayer structural lipids, specifically MGDG, is crucial for the effective functioning of the XC, as it facilitates the solubilization of xanthophylls and the incorporation of de-epoxidase into the membrane. It is likely that EPA within MGDG in diatoms plays a key role in the rapid operation of the XC by conferring the structural lipid molecules with the necessary inverted conical shape. This shape cannot be fully achieved by the less unsaturated shorter chain of ALA.

In recent decades, many freshwater and coastal marine ecosystems have experienced increased inputs of chromophoric dissolved organic matter (CDOM) of terrestrial origin, primarily humic substances (HS). This phenomenon, commonly referred to in English-language literature as brownification, involves the darkening of water bodies due to elevated concentrations of colored organic compounds. The influx of HS into aquatic systems alters the optical, chemical, and trophic characteristics of the water column. This interdisciplinary review synthesizes current scientific knowledge on the effects of humic substances on phytoplankton primary production, trophic structure, and community composition under conditions of climate change. Key mechanisms are examined, including reduced light penetration, enhanced thermal stratification, nutrient transport, and the involvement of HS in redox processes. Evidence suggests that moderate humification can stimulate productivity through microbial degradation and photodecomposition of allochthonous organic matter, releasing additional nutrients. However, at high HS concentrations, photosynthetic activity declines, phytoplankton shift toward mixotrophy, and biodiversity decreases. Altered light spectra favor groups with accessory pigments and vertical mobility, such as cryptophytes, dinoflagellates, and cyanobacteria, potentially reducing ecosystem trophic efficiency. Ecosystem responses to humification vary with geographic, climatic, and morphometric characteristics of water bodies. Special attention is given to boreal and Arctic regions, where permafrost thaw and increased precipitation intensify HS runoff. Key research directions are identified, including thresholds of abrupt change, the role of mixotrophy in carbon cycling, and the development of region-specific adaptation strategies. The review underscores the importance of an integrated approach to assessing the ecological consequences of aquatic humification.

The results of DNA barcoding of Tubifex tubifex from various freshwater bodies within the Vychegda River basin (Komi Republic, Russia) are discussed. A molecular genetic analysis of 32 specimens collected from 14 locations, based on nucleotide sequences of the mitochondrial cytochrome c oxidase subunit I (cox1) gene fragment, revealed six distinct lineages (A, B, C, D, E, J) exhibiting inter-lineage divergence exceeding 17-24 %. A significant correlation was identified between the genetic diversity of the species and habitat characteristics, including hydrological and hydrochemical parameters of water and sediments. The observed ecological differentiation supports the presence of heterogeneous adaptive traits within T. tubifex and highlights the importance of considering population genetic structure in ecological assessments of freshwater ecosystems.

The article analyzes retrospective literature data and the results of our own research on ichthyoplankton in the coastal waters of southeastern Crimea (the waters of the Karadag Nature Reserve) over the period 1950-2024. Samples were collected in the coastal zone using vertical and horizontal surface fishing methods. Information on taxonomic composition, structure, and abundance dynamics of ichthyoplankton are presented. During a 70-year research period, eggs and larvae of 66 fish species from 33 families were identified. The recovery of ichthyoplankton abundance and species composition after the collapse of the Black Sea ecosystem in the 1990s occurred against the background of climatic changes that significantly impacted the hydrological regime and thermohaline structure of waters in the Azov-Black Sea Basin. In recent years, there has been an increase in the number of species, including due to the introduction of Mediterranean species, and a change in the dominance and sub-dominance of species has occurred.

Structural and functional characteristics of plankton communities are widely used as ecological indicators of global ocean warming. In terms of long-term variability, they indicate the existence of monotonous negative, positive and “zero” trends, i. e. their absence. The latter can be considered as phenomena of regional resilience of plankton communities to global warming. Based on the materials of regional sampling and international databases, an analysis of the interannual variability of zooplankton biomass and indices of its species diversity in the Arabian, Mediterranean and Black seas (from 2000 to 2023) was carried out. For comparison, data on biomass measurements in five other regions of the Atlantic and Pacific Oceans were used. It is shown that the duration of the existence of phenomena of regional stability of plankton communities ranges from several to tens of years, in a wide range of species diversity and biological productivity of waters. In most of the studied regions, the absence of interannual trends in zooplankton biomass corresponded to their absence in the interannual variability of chlorophyll a concentration as an indicator of phytoplankton biomass. Such a correspondence indirectly indicates a trophic basis for the interannual stability of zooplankton biomass.

The results of an experimental study of the influence of tabs (teeth) of various shapes on the intensity of turbulent heat transfer in the separation zone in the near wake of a backward-facing step are presented. In this stagnation region, a significant decrease in heat transfer is observed, which negatively affects the thermal-hydraulic efficiency. Five tab shapes were studied in the experiments: square, triangular, cylindrical, semi-cylindrical, and semi-conical ones. The tabs were installed at the step edge immediately before flow separation. Measurements were conducted at Reynolds number Re_Н = 4000 and varying tab pitch. It was found that square tabs with a pitch of 2.5 calibers (step height) have the greatest effect on flow and heat transfer, but at the same time, they cause the greatest hydraulic resistance, therefore, their thermal-hydraulic efficiency is lowest. Semi-conical tabs installed with a pitch of five calibers showed the best results.

Experimental results on the diffusion combustion of a hydrogen microjet escaping from a sphere enveloped in an air flow are presented. Two limiting cases of the outflow of a burning hydrogen microjet are considered: when the jet is located at the flow divergence point on the sphere and at the opposite point, at the aft end of the sphere, where different separated flow structures are realized. Three characteristic hydrogen microjet flow velocity regimes were studied, allowing for the creation of various burning jet structures at zero incident flow velocity. The changes in the jet topology and structure were demonstrated. Flow visualization was performed using a thermal imager. A comparison was made with results obtained using a shadowgraph.

The dynamics of dispersed phase propagation during injection of a gas-droplet wall jet into a co-current turbulent heated airflow is numerically simulated with variations in the droplet mass concentration at the inlet cross-section and their initial diameter. The solution is based on a system of axisymmetric Reynolds-averaged Navier-Stokes (RANS) equations, taking into account the two-phase character of the flow. The Eulerian approach is primarily used to describe the aerodynamics and heat and mass transfer in the gas and dispersed phases. The Lagrangian and full Lagrangian approaches are used in the study for additional verification of the developed mathematical model. A significant effect of the liquid mass concentration on the particle concentration profiles across the channel cross-section is demonstrated. The results obtained using the Eulerian and Lagrangian descriptions are compared. The applicability of both approaches for describing the dynamics and heat transfer of a two-phase wall jet is demonstrated (the difference between the two approaches does not exceed 15%).

A numerical study of the flow in a tangential vortex chamber using unsteady full and Reynolds-averaged Navier-Stokes equations is presented. The spatial flow of a viscous incompressible gas (air) is considered at Reynolds number Re = 3.4·10⁴. The distributions of the axial and circumferential velocity components, as well as their pulsations, are analyzed. It is established that the solution of the full Navier-Stokes equations provides distribution of parameters in a swirling flow close to the results of experimental measurements, whereas turbulence models based on the Boussinesq hypothesis do not allow numerically reproduction of the dynamics of a confined swirling flow.

Ground-based simulation of processes around space vehicles in open space is a topical issue for rocket industry. Some problems can be covered by middle-size vacuum-based gas-dynamic setups; they provide model flow regimes for imitation of natural regimes befitting from low financial and material costs. The updates for the laboratory vacuum setup LAMPUS-2 based in Novosibirsk State University and improvements in gas dynamic diagnostic tools enabled a wide range of study for supersonic jets emerging from a nozzle cluster. This paper presents the measurement results performed for binary cluster jets using photo visualization method and scanning of argon flows for different ratio of stagnation pressure to the ambient pressure. The process of condensation has a significant influence on the dynamics of interacting jets.

The three-dimensional structure of the flow in narrow gaps between fuel assembly (FA) rods has a decisive influence on the heat and mass transfer coefficients, which, in turn, determine the FA performance. In this work, instantaneous three-dimensional velocity fields were measured for the first time in a model of a FA peripheral cell using the Tomographic PIV method with high temporal resolution. The experiments were performed at Reynolds number Re = 2100. The study, conducted using the TR-Tomo PIV method, allowed characterization of the three-dimensional structure and dynamics of the flow in a narrow gap of a FA peripheral cell. Based on the obtained data, the components of the vorticity vector in the flow volume were calculated. It is shown that the key mechanisms, responsible for generation of extreme values of longitudinal vorticity, are transverse flow oscillations. These oscillations are quasi-periodic in nature (Sh = 0.091) and alternate with stabilization phases, which are characterized by a straight-through flow.

A newly discovered phenomenon-the sudden dispersion of starch grains upon a sharp decrease in ambient pressure-was experimentally studied. The aim of the study was to determine the mechanism of this phenomenon. This effect was observed for various types of starch: potato, corn, and rice. It was established that starch moisture content is the primary parameter determining the occurrence of this phenomenon. The experimental results showed that grain dispersion occurs due to the reactive force generated by evaporation and release of water from the starch grains. The release is caused by an increase in water vapor pressure within the starch grains due to a phase transition of water upon a decrease in external pressure. The data obtained may be useful for further research in materials science and biotechnology, as well as for the development of new methods for studying the properties of starch materials.

The development of optoelectronic methods for measuring through a multiphase barrier in the study of a dispersed component in experiments on modeling the natural and technical hydrodynamic systems is a pressing issue. The difficulties of direct measurements under hurricane conditions necessitate laboratory measurements. Spray formation was studied in detail during the laboratory experiments in the high-speed wind-wave channel (WWC) at the Institute of Applied Physics of the Russian Academy of Sciences (IAP RAS). A modern, non-contact optical method for diagnosing two-phase flows-laser Doppler anemometry (LDA)-was used to measure the kinematic characteristics of the aerosol flow. Experiments were carried out to measure the aerosol droplet aerodynamics in WWC of IAP RAS. It was demonstrated that the measuring system enables to measure all three components of the aerodynamic flow velocity through a multiphase barrier at wind speeds from 10 to 40 m/s over a wide range of conditions. The results of measurements were compared with the readings of the Pitot tube, and good agreement and reproducibility of the experimental results were shown.

The purpose of this study is to substantiate the existence and prevalence of the phenomenon of dynamic equilibrium in the development of morphological patterns of permafrost landscapes, the related regularities, and the possibilities of their application for forecasting and analyzing processes. The state of dynamic equilibrium in the development of morphological patterns is quite common for certain permafrost landscapes, such as abrasion and thermo-erosional shores, thermokarst plains with fluvial erosion, and floodplains. It is characterized by a combination of constant changes in the elements of the morphological pattern with the constancy of its characteristics (first of all, quantitative) for the landscape as a whole. A promising way to substantiate the existence of dynamic equilibrium of the morphological pattern of a given landscape is to analyze its mathematical model. It is argued that the state of dynamic equilibrium is reflected in a number of specific statistical characteristics. Thus, for thermokarst plains with fluvial erosion, a consistent statistical (integral-exponential) distribution of thermokarst lake areas and a correlation between the average area of thermokarst lakes and the average area of alas depressions (khasyreys) are observed. The obtained information on the state of dynamic equilibrium can be used for planning landscape monitoring, as well as for determining the quantitative parameters of dynamic landscape processes on the basis of the analysis of the quantitative characteristics of its morphological pattern without stationary observations.

An increase in air temperature entails an increase in soil temperature, which is dangerous for buildings and structures constructed with the foundation soils preserved in a frozen state. One of the most common methods of maintaining the frozen state of foundation soils is the construction of a ventilated basement. This system cools the soil by circulating cold atmospheric air. However, with the rise in the mean monthly temperature, the efficiency of the ventilated basement decreases. In a number of regions, the construction of buildings with a ventilated basement without additional measures to cool the foundation soils is already insufficient and may lead to the instability of buildings during their operation. In this paper, analytical calculations are carried out to determine the critical year for the loss of efficiency of ventilated basements according to data from weather stations in the north of European Russia and Western Siberia, as well as in the Central and Eastern Siberia. These calculations are based on representative values of the maximum soil temperature at the base of the pier foundation at the edge of the building with ventilated basement for the beginning of operation in 2025, 2075, and 2125.

The article discusses issues related to the stability of bases and foundations of buildings in the town of Tiksi, Bulunsky district, Sakha Republic (Yakutia). In August 2023 and July 2024, the authors conducted a complete visual survey and selective instrumental inspection of foundations of buildings and measured temperatures in operating thermometric boreholes in Tiksi; scientific and technical literature on research conducted in Tiksi and its environs was analyzed. This study made it possible to identify the main factors currently affecting the stability of foundations: improper maintenance and leaks of utility networks, excessive snow accumulation, and snow drift. In addition to the development of taliks in the bases of buildings and temporary structures, these factors lead to cryogenic weathering of concrete foundation structures.

The problem of railway operation in permafrost areas is associated with the degradation of permafrost at the subgrade base. A concept of the combined thermal stabilization of the subgrade base soils through their rapid cooling with liquid nitrogen with long-term maintenance of subzero temperatures using a vapor-liquid seasonal cooling device is suggested for the conditions that require immediate response to eliminate possible frost heaving. The results of a large-scale laboratory experiment allowing us to compare the efficiency of the combined thermal stabilization device with the widely used vapor-liquid seasonal cooling devices are presented. The experiment provided qualitative and quantitative empirical data for further substantiation and verification of analytical or numerical methods of thermal stabilization calculations in the chosen direction. Additionally, heat losses during the operation of the combined device in the rapid cooling mode with liquid nitrogen have been estimated.

This study presents a comprehensive analysis of regional climate dynamics - specifically, solid precipitation - and its impact on mountain geosystems in the Kuznetsk Alatau. The research integrates long-term field observations with ERA5-Land reanalysis data, focusing on snowpack measurements across the Kanym Highlands (2011-2025). We detail the spatial distribution, parameters, and temporal variability of snow cover, including avalanche hazards and maximum snow redistribution volumes. Additionally, we provide new UAV-based monitoring results (2024) for the Iyus-Tersa glacier group, alongside a detailed assessment of six major glaciers’ retreat since the 1980s. The surface temperatures in the different landscapes (900-1500 m a.s.l.) were investigated. The well-documented snowpack dynamics of the Kanym Highlands and Iyus-Tersa glaciers enable a comparative analysis, shedding light on local geosystem responses to climate warming and associated physiographic changes. Our validation shows that while ERA5-Land reliably estimates ten-day mean snow depth at the foothills, it underestimates snowpack thickness in high-altitude cryosphere zones, underscoring the critical role of in situ measurements.

A key feature of the upper part of geological sections in the Arctic is the presence of permafrost, with which a number of cryogenic phenomena - thermokarst, frost mounds, gas-emission craters, etc. - are associated. These phenomena represent significant geohazards potentially causing large-scale negative consequences in the context of the actively developing oil and gas infrastructure. of the region. In this paper, some results from the interpretation of high-density shallow (up to 500 m) transient electromagnetic method data obtained in the eastern part of the Yamal Peninsula to identify fluid migration channels, which may be associated with the formation of frost mounds. It has been established that the distribution of frost mounds in the study area correlates with anomalies in polarizability and electrical resistivity. The layer of rocks, above which pingo-like landforms are found, is associated with the manifestation of inductively induced polarization likely characteristic of sediments with the low ice content, In the underlying strata, anomalies of reduced resistivity are noted, which may be associated with fluid migration channels and accumulations of gaseous hydrocarbons in the permafrost.

This article presents the results of a GPR study at groundwater discharge sites located in the Makhatta and Kysyl-Syr tukulans (Republic of Sakha (Yakutia)). GPR profiles were obtained using 50 and 150 MHz antenna systems, characterizing the structure of sandy sediments and the boundaries of suprapermafrost subaerial taliks. In the southeastern margin of the Makhatta Tukulan, groundwater boundaries with a depth of 4.5-10 m in different lithological conditions were identified. In the Kysyl-Syr Tukulan, watered horizons with a width of 550 m and a depth of 13-32 m forming complex channels of groundwater migration and discharge were detected.

As a result of studying the collections of Herbariums ABG, LE, MW, MHA, NSK, NS, TK, ALTB, as well as their own expedition collections, information about the species composition of the genus <i>Geranium</i> L. in the flora of the Republic of Kazakhstan has been clarified. For the first time, the species <i>G. transbaicalicum</i> Serg was identified in the flora of Kazakhstan. The ranges of <i>G. affine , G. asiaticum , G. collinum , G. divaricatum , G. pratense , G. sergievskajae , G. pseudosibiricum, G. pusillum , G. robertianum , G. schrenkianum , G. sibiricum , G. sylvaticum , G. transversale , and G. turczaninovii</i> species in Kazakhstan have been supplemented. The lectotype of <i>G. regelii</i> Nevski is designated. A key has been compiled to identify the species.

The nothospecies Galatella × tzvelevii Vasjukov et Saksonov (Asteraceae), derived from a hybridization of G. biflora (L.) Nees × G. villosa (L.) Rchb. f., was described in 2015 from a single flowering specimen in the Samara Region. While working at the I.I. Sprygin Herbarium (RKM) of Penza State University, we discovered another specimen of this nothospecies, designated here as the epitype of the name of this taxon. Characters supplementing the morphological description of the nothospecies given in the protologue, as well as characteristics of the parental species, are discussed. A new locality for G. × tzvelevii from the Republic of Bashkortostan is also presented.

Siberian iris Iris sibirica L. (Iridaceae) is known as a species included in many regional Red Books and has valuable ornamental and medicinal properties. The lack of a unified approach to overcoming dormancy, which is characteristic to varying degrees of mature seeds of many iris species, usually complicates their micropropagation. This study allowed us to determine the conditions that facilitate the germination of both mature and immature seeds of I. sibiricain vitro culture. The effect of 6-benzylaminopurine (6-BAP) on the morphogenetic potential of I. sibirica was assessed, which made it possible to create a protocol for effective microclonal propagation of the species. Data were obtained on the stimulation of I. sibirica seed germination in order to obtain adventitious shoot formation by direct organogenesis without callus formation. It was found that the use of cytokinin 6-BAP at a concentration of 1 mM is most effective for obtaining, on average, 3-4 adventitious shoots in seedlings obtained from immature seeds, as well as for increasing the energy of seed germination regardless of their maturity. At a low concentration of cytokinin, no violation of the ability of adventitious shoots to rhizogenesis was noted, which made it possible to obtain microclones with a well-developed root system when transplanted to a hormone-free medium. The deposition of microclones for 2 months at a low temperature allowed increasing the survival rate of regenerated plants to 86.5 % when they were subsequently transferred to ex vitro conditions. The plants developed at an accelerated rate, which allowed most seedlings to bloom in the second year after transplantation to the introduction site. This work is relevant for obtaining a large amount of plant material, both for further study and for preserving the species in vitro and ex situ , given that the habitats of I. sibirica are subject to anthropogenic impact and some populations listed in the Red Books have not been found again.

The pine and small-leaved pine grass forests of the North-Western Caucasus are proposed to be considered as part of a special subzonal geographical type - the European-Siberian hemiboreal forests. The results of the analysis of the spectrum of phytocenotic groups demonstrated the highest importance of light-depending mesophilous species of subalpine-forest and “betular” (related to birch forests) phyto-cenoenotic elements, as well as the important role of subalpine species along with the weak participation of shade-tolerant nemoral plant species. The results of the geographical analysis of the floristic composition revealed the predominance of widespread species (of Eurasian, European-Siberian and West Palearctic chorological groups), as well as endemic Caucasian taxa. According to the proposed concept of the genesis of the Caucasian hemiboreal forests, the high level of endemism is a consequence of their autochthonous floro-genesis at the upper boundary of the forest belt in the Pliocene. At the same time, the significant participation of European-Siberian, Western Palearctic and Eurasian chorological groups is the result of active migrations of plant species in hemiboreal forests predominated during the Quaternary period in forest and forest-steppe zones of Northern Eurasia.

New syntaxa are described, validation of alliance is carried out. New data on the distribution of plant communities, their ecology and composition are given. Alliance Carici supinae-Stipion zalesskii Korolyuk all. nov. Holotypus - ass. асс. Artemisio austriacae-Stipetum capillatae Schubert, Jager et Mahn ex Korolyuk 2014. Diagnostic species (D. s.): Artemisia austriaca , Carex supina , Festuca valesiaca , Potentilla humifusa , Seseli ledebourii , Stipa capillata , S. zalesskii. The alliance unites bunchgrass typical steppes of the steppe zone of the Trans-Volga-Kazakhstan steppe province (Lavrenko et al., 1991). It is characterized by prevalence of widespread steppe xerophytes, including bunchgrasses. Three associations within the alliance have been described. Ass. Artemisio austriacae-Stipetum capillatae Schubert, Jager et Mahn ex Korolyuk 2014 - bunchgrass typical steppes of Western Siberia, the Urals, the Southern Urals, the Trans-Urals, and Northern Kazakhstan. D. s.: Artemisia austriaca , Carex supina , Festuca valesiaca , Potentilla humifusa , Seseli ledebourii , Stipa capillata , S. zalesskii . Ass. Artemisio nitrosae-Festucetum valesiacae Zolotareva, Korolyuk et Makunina 2023 - steppes on sandy soils. D. s.: Artemisia nitrosa , Camphorosma monspeliaca , Kochia prostrata . Ass. Gypsophilo paniculatae-Artemisietum glaucae Korolyuk 2014 Zolotareva, Korolyuk et Makunina 2023 - steppes on sandy soils. D. s.: Artemisia frigida , A. marschalliana , Cleistogenes squarrosa , Gypsophila paniculata , Helichrysum arenarium , Silene borysthenica , S. borysthenica . A new association is described in the class Salicetea herbaceae Br.-Bl. 1948, the order Salicetalia herbaceae Br.-Bl. in Br.-Bl. et Jenny 1926 and the alliance Saxifrago stellaris-Oxyrion digynae Gjaerevoll 1950. Ass. Hymenolomo crispuli-Salicetum polaris Sinelnikova ass. nov. (Suppl., Table 2) - snowbed communities of the class Salicetea herbaceae Br.-Bl. 1948 in the highlands of the south-eastern spurs of the Chersky ridge (Magadan Region). D. s.: Anthelia juratzkana , Bistorta elliptica , Carex podocarpa , Hymenoloma crispulum , Lagotis minor , Salix polaris. The association includes two subassociations - typicum (Suppl., Table 1, rel. 1-24) and rhodioletosum quadrifidae (Suppl., Table 1, rel. 24-37). A new association is described in the class Festucetea vaginatae Soό 1957, the order Festucetalia vaginatae Soό 1957 and the alliance Sileno borysthenicae-Cleistogenion squarrosaeKorolyuk 2017. Ass. Kitagawio baicalensis-Festucetum beckeri Chupina ass. nov. (Suppl., Table 3) - psammophytic steppes on the terraces of the right bank of the Ob river. D. s.: Kitagawia baicalensis , Melilotus albus , Vicia amoena , Vincetoxicum sibiricum , Hippophae rhamnoides. The article presents new data on the distribution of the associations from the class Therosalicornietea Tx. in Tx. et Oberd. 1958: Salicornietum perennantis (Soó ex Wendelberger 1943) Soó 1964 nom. corr. (Suppl., Table 3, 4), Salicornio perennantis-Suaedetum salsae Freitag, Golub et Yuritsina 2001 (Suppl., Table 5), Suaedetum kulundensis Korolyuk 2010 (Suppl., Table 6), Suaedetum salsae Golub et Tchorbadze in Golub 1995 (Suppl., Table 7), Artemisio nitrosae-Camphorosmetum songoricae Korolyuk 1999 (Suppl., Table 8), Suaedetum corniculatae Burtseva in Mirkin et al. 1992 (Suppl., Table 9), Suaedo corniculatae-Camphorosmetum songoricae Korolyuk 1999 (Suppl., Table 10).

The freshwater benthic alga Hydrurus foetidus (Villars) Trevisan was first found in the Iy-Khem River in the Todzha Basin of the Tyva Republic. Geographically, the species is widespread, but it usually grows only in cold waters. The recorded occurrence of H. foetidus in waters with a temperature of 20-21 °C significantly expands our understanding of the ecological distribution of this species. The first discovery of the species in the waters of the Todzha Basin adds to our knowledge of the diversity of algae in the Tyva Republic.

The flora of Omsk Region remains insufficiently and unevenly studied. This is confirmed by numerous findings made during floristic research, which determines the relevance of continuing flora inventory work. The article presents the results of studies of the vascular plant flora of the region for the period 2013-2024. The work was carried out within the framework of the “Flora of Asiatic Russia 2.0” project and is based on field data and verified observations from the iNaturalist platform. For the first time in the region, 28 species and 5 hybrids have been identified, of which 12 species and 4 hybrids are native, while 16 species and 1 hybrid are adventive. Among adventive species, ergasiophygophytes (11 species) predominate, while by degree of naturalization, epecophytes (6 species), ephemerophytes (4 species), colonophytes and ephemerophyte-epecophytes (3 species each) are distinguished. Additional studies are required on the distribution of Sorbus aucuparia L. and Leucanthemum ircutianum DC. in the region. Widely cultivated species ( Cucurbita maxima Duchesne, C. pepo L., Solanum lycopersicum L., S. tuberosum L.) occasionally become wild and persist for a short time near cultivation sites (garden plots, individual residential areas) and landfills. Four rare species have been proposed for inclusion in the Red Book of Omsk Region: Dianthus krylovianus Juz., Astragalus lagobromus Knjaz. & Kulikov, Bupleurum aureum Fisch. and Eremogone koriniana (Fisch. ex Fenzl) Ikonn . The study results significantly expand the known vascular plants flora of Omsk Region, this is of great importance for biodiversity conservation and planning of environmental protection measures.

The article contains personal memories of meetings with the outstanding botanist Andrey Pavlovich Khokhryakov (1933-1998), which had a significant influence on the author’s professional path. It describes striking moments of joint expeditions, seminars, and scientific discussions that reveal the unique talent and personal qualities of the scientist. The article provides information about Khokhryakov’s contributions to various fields of botany and emphasizes the significance of his ideas and work for modern science.

The review of publications (106 sources) on the history of the Central Siberian Botanical Garden of the Siberian Branch of the Russian Academy of Sciences for the period from the moment of the first newspaper appeals about the organization of the botanical garden in Novosibirsk (1939, 1945) to the present is given. The publications are organized into blocks on general history, memorial dedications, the history of scientific fields and/or laboratories, and the memoirs of employees. The review of historical literature makes it possible to evaluate the contribution of four generations of researchers and staff of the Botanical Garden to the organization of botanical science in the conditions of the Soviet period, during the “perestroika period” and in the first decades of the new century. The collected materials are the basis for the work of the “Botanical Museum of Siberia” to preserve the history of the Central Siberian Botanical Garden SB RAS.