Climate warming is likely to increase the physical connectivity of ecosystems with their surroundings. For Arctic lakes, increasing meltwater and precipitation may enhance the inputs of nutrients, organic matter and microorganisms from their catchments, and the increasingly ice-free, open-water conditions of the Arctic Ocean may favor increased inputs of marine aerosols, including microbiota. This study therefore aimed to determine how changing connectivity to terrestrial and marine habitats may affect the dispersal, sorting, and establishment of bacterial communities in a coastal High Arctic lake. Three habitats in this model system were sampled for ice, water, and snow: the lake, inflowing water tracks over permafrost soils, and an adjacent ice-dammed bay connected to the Arctic Ocean. Lake water chemistry confirmed the hydrological connection between the lake and terrestrial habitats, with the lake fed by terrestrial carbon sources via snow and groundwater run-off. Sequencing of 16S rDNA and rRNA showed evidence of a small marine and terrestrial influence on the lake, but few bacterial phylotypes were common to all three connected habitats. These results imply ongoing strong environmental filtering by habitat type, despite the apparent and potentially rising connectivity, and provide an example of bacterial resilience in a region of rapid climate change.

Land surface temperature (LST) is a key indicator reflecting the ecological environmental disturbance caused by open-pit coal mining activities and determining the ecological status in alpine permafrost regions. Thus, it is crucial to study the spatiotemporal variations and influencing mechanisms of LST throughout all stages of small-scale mining–large-scale land surface damage–ecological restoration. Landsat imagery over nine periods was extracted from the growing seasons between 1990 and 2024. This study retrieved LST while simultaneously calculating albedo, soil moisture, and normalized difference vegetation index (NDVI) for each time phase. By integrating land use/cover (LUCC) data, the spatiotemporal evolution patterns of LST in the mining area throughout all stages were revealed. Based on the Geodetector method, an identification approach for factors influencing LST spatial differentiation was established. This approach was applicable to the entire process characterized by significant land type transitions. The results indicate that the spatiotemporal variations in LST were significantly correlated with land surface damage and restoration caused by human activities in the mining area. With the implementation of ecological restoration, high and ultra-high temperatures decreased by about 25.98% compared to the period when the surface damage was the most severe. The main influencing factors of LST differentiation were identified for different land use types, i.e., natural and restored meadows (soil wetness, albedo, and NDVI), mine pits (albedo, aspect, and elevation), and mining waste dumps (aspect and albedo before restoration; aspect and NDVI after restoration). This study can provide a reference for monitoring the ecological environment changes and ecological restoration of global coalfields with the same climatic characteristics.

Cold environments, including glaciers, ice sheets, permafrost soils and sea ice, are common across the surface of the Earth. Despite the challenges of life at subzero temperatures, the global cryosphere hosts diverse microbial communities that support biogeochemical cycling and ecosystem functioning in areas where few other organisms can survive. However, the composition and function of cryosphere microbial communities, and the continued existence of cryosphere habitats, are threatened by ongoing climate change, which has disproportionate impacts in polar regions. In this Review, we survey the breadth of cryosphere habitats and the composition, function and unique adaptations of the microbial communities that inhabit them. We outline how climate change can affect these communities and the ecosystem services they provide through short-term changes in substrate availability, enzyme activity and redox potentials as well as longer-term changes in community composition. We also explore the wide-ranging consequences these changes may have for local ecosystems, human communities and the global climate. Finally, we outline the knowledge gaps in cryosphere microbial ecology that contribute to uncertainties about the future of these ecosystems in a warming world.

This paper examines the stress-strain state of a tank using data obtained through hybrid monitoring conducted in permafrost conditions. Hybrid monitoring integrates traditional geodetic surveys of the tank walls, levelling of the tank bottom, and automated settlement control of the central part of the bottom during the tank's operation. The authors applied a numerical method using the ANSYS software environment. Also, they reviewed three calculation options: one utilizing geodetic control data for the wall and bottom, another incorporating extensometer measurements, and a third combining deformation history data of the tank along with extensometer readings. The study found that settlements in the central bottom lead to localized zones of stress concentration in the tank wall. Additionally, accumulated deformations create an initial stress-strain state in the structure, which deteriorates as the tank continues to deform. The integration of hybrid monitoring with numerical modeling enables predictions of changes in the tank’s stress-strain state. These predictions form the basis for developing preventive measures to avert accidents.

Impaired sustainability of thawing permafrost peatland ecosystems by Siberian alder colonization.

The development of hydrocarbon production sites in permafrost zones and the need to reduce costs require a more thorough study of the requirements for the materials and structures used. An analysis of regulatory and technical documentation revealed that some of these requirements are unreasonably high. Thus, SP 16.13330.2020 specifies that when manufacturing bored precast foundation piles, it is necessary to ensure an impact toughness level of welded joints obtained by high-frequency welding of at least 34 J/cm2 at a temperature of -60 °C. This requires extensive post-weld heat treatment of the pipes from which the piles are made, dramatically increasing the cost of the structure and leading to higher construction costs. It should be noted that GOST 20295, which is used to manufacture pipes for the piles, and similar regulatory and technical documents do not contain such requirements. An analysis of the mechanical properties and residual welding stresses in the pipes with and without heat treatment was conducted. Field tests of bored precast piles installed in the permafrost zone were also conducted. The conducted studies allow to conclude that the requirement for heat treatment of the pipes is excessive and should be eliminated.This work was carried out as part of a state assignment from the Ministry of Science and Higher Education of the Russian Federation (Topic No. FSEG-2024-0009: Development of models for the degradation of the performance properties of metallic and composite materials for construction in permafrost soils).

Abstract The warming Arctic could accelerate climate change as permafrost soil carbon is released as greenhouse gas emissions from boreal forest, tundra, and wetland ecosystems. Record climate conditions are increasingly common, with the 2023–2024 winter (September–April) documented as having the warmest land surface air temperatures on record for the Arctic region. However, corresponding impacts on ecosystem greenhouse gas fluxes typically take several years to diagnose, creating a knowledge gap between contemporary climate events and these fluxes. Here we synthesized near real-time data from 19 eddy covariance flux tower sites across the Arctic through the summer of 2024. This analysis revealed record net carbon dioxide and methane emissions occurring in winter, coinciding with warm 2023–2024 winter conditions. The increasing recognition of the importance of winter in shaping ecosystem carbon balance is still challenged by the difficulty of collecting data, with far more carbon flux measurements available in summer as compared to year-round. Improving the observation network’s extent and ability to deliver near real-time updates could provide immediate knowledge about the speed and strength of the permafrost carbon feedback to climate change. This increased awareness could help nations adapt their emissions policies aimed to avoid the worst impacts of climate change.

Abstract. The Antarctic environment is amongst the coldest and driest environments on Earth. The ultraxerous soils in the McMurdo Dry Valleys support exclusively microbial communities, however, 15 million years ago, a tundra ecosystem analogous to present-day southern Greenland occupied this region. The occurrence of ancient soil organic carbon combined with low accumulation of contemporary material makes it challenging to differentiate between ancient and modern organic processes. Here, we explore the additions of modern organic carbon, and the preservation and degradation of organics and lipid biomarkers, in a 1.4 m mid-Miocene age (∼14.5–14.3 Ma) permafrost soil column from Friis Hills. The total organic carbon is low throughout the soils (<1 wt %). The near-surface (upper 35 cm) dry permafrost has lower C:N ratios, higher δ13Corg values, higher proportion of branched fatty acids with an iso and anteiso configuration relative to n-fatty acids, lower phytol abundance and higher contributions of low-molecular weight homologues of n-alkanes, than the underlying icy permafrost, indicating higher contributions from bacteria-derived organic matter. Conversely, the icy permafrost contains higher molecular weight n-alkanes, n-fatty acids and n-alkanols, along with phytosterols (e.g. sitosterol and stigmasterol) and phytol (and its derivatives pristane and phytane) that are indicative of the contributions and preservation of higher-level plants. This implies that legacy mid-Miocene age carbon in the near-surface soils (ca. 35 cm) has been prone to microbial organic matter degradation during times when the permafrost thawed, likely during relatively warm intervals through the late Neogene (∼6.0 Ma) and sporadically during the Holocene (<1 %), when ground summer temperatures were ≥+2 °C (based on branched glycerol dialkyl glycerol tetraether (brGDGT) temperature reconstructions). Conversely, lipid biomarkers found deeper in the permafrost have been preserved for millions of years. These results suggest that ancient organics preserved in permafrost could underpin significant ecological changes in the McMurdo Dry Valleys under the current warming climate.

The problems of ensuring safe operation of critical facilities and structures under construction and in operation are more relevant than ever today. The technology of sinking and construction of a shaft on the territory of the mining and concentration plant in Petrikov (Republic of Belarus) was associated with freezing of the soil mass, therefore, the foundation of the mine structure was built on a site located within the zone of frozen soils. Due to thawing of the soil mass which was taking place over many months, the base of the structure built above the mine to hoist the potash ore was subjected to dangerous mancaused effects. The paper describes the experience of using a system for continuous monitoring of the deformation parameters of a structure during its installation and commercial operation. The paper presents the results of long-term monitoring of the deformation behavior of the building structures that demonstrate stabilization of the deformation parameters during the final thawing of the soils around the shaft. Due to the fact that the issue of foundation soils thawing at the described facility is phenomenologically similar to the problem of the permafrost soil thawing in the north of the Russian Federation, the results of the study can be used as the basis for a developed method of monitoring and analyzing the deformation behavior of the building structures for Arctic conditions in the permafrost zone.

Alpine permafrost plays a vital role in regional hydrology and ecology. Alpine permafrost is highly sensitive to climate change and human disturbance. The Muri area, which is located in the headwaters of the Datong River, northeast of the Tibetan Plateau, has undergone decadal mining, and the permafrost stability there has attracted substantial concerns. In order to decipher how and to what extent the permafrost in the Muri area has responded to the decadal mining in the context of climate change, daily MODIS land surface temperatures (LSTs) acquired during 2000–2024 were downscaled to 30 m × 30 m. The active layer thickness (ALT)–ground thaw index (DDT) coefficient was derived from in situ ALT measurements. An annual ALT of 30 m × 30 m spatial resolution was subsequently estimated from the downscaled LST for the Muri area using the Stefan equation. Validation of the LST and ALT showed that the root of mean squared error (RMSE) and the mean absolute error (MAE) of the downscaled LST were 3.64 °C and −0.1 °C, respectively. The RMSE and MAE of the ALT estimated in this study were 0.5 m and −0.25 m, respectively. Spatiotemporal analysis of the downscaled LST and ALT found that (1) during 2000–2024, the downscaled LST and estimated ALT delineated the spatial extent and time of human disturbance to permafrost in the Muri area; (2) human disturbance (i.e., mining and replantation) caused ALT increase without significant spatial expansion; and (3) the semi-arid climate, rough terrain, thin root zone and gappy vertical structure beneath were the major controlling factors of ALT variations. ALT, estimated in this study with a high resolution and accuracy, filled the data gaps of this kind for the Muri area. The ALT variations depicted in this study provide references for understanding alpine permafrost evolution in other areas that have been subject to human disturbance and climate change.

In some cases, when drilling piles are installed in permafrost soils, mixtures are made with chemical additives to ensure concrete hardening. During such piles installation heat and mass transfer between the concrete mixture and the soil occurs, which lead to artificial base salinization. Presently the regulator does not recommend to use such piles in the cryolithozone due to insufficient knowledge and lack of reliable calculation methods. The purpose of the work described in this article was to refine the methodology for the bearing capacity of drilling piles in artificially salted permafrost soils determining. Comparative analysis has shown the insufficient accuracy of the standard method for shear strenth determining. Proposals to refine the methodology for the determining bearing capacity of piles by introducing an operating conditions coefficient γsh,sal assumed to be equal to the ratio of the calculated frozen soil shear strenth in artificially salted and unsalted conditions are made. The maximum long-term artificially salted soil shear strenth is proposed to determine depending on the salinity degree, and the pore solution concentration to determine by calculation using a known model. The methodology was tested using data from static tests of full-scale piles by calculating a set of coefficient values for sandy soil and a concrete mixture including sodium methanoate as an antifreeze component and a multifunctional modifier. It is shown that the improved methodology makes it possible to increase the calculation reliability.

Abstract Global warming is transforming High Arctic ecosystems, yet the effects of northward vegetation expansion on soil microbial functions remain unclear. A four-year field experiment in northern Greenland was conducted to study these impacts. We investigate how plant litter affects the active layer and thawing permafrost soils by transplanting the latter from deeper soil layers and supplementing active layer soils with Arctic shrub litter. Litter amendment altered the soils’ functional potential, including the enrichment of genes linked to ion and lipid transport, metabolism and secondary metabolite production, ultimately enhancing microbial growth and respiration. Significant alterations were observed in carbon (C) and nitrogen (N) cycling genes, marked by an enhancement of CAZymes related to the breakdown of specific C substrates such as cellulose, hemicellulose, pectin, murein and chitin. Litter amendment also shifted the microbial N-cycling potential towards increased N mineralization and assimilation of organic and inorganic N, suggesting an increased incorporation of N into microbial biomass. Without litter amendment, few C- and N-metabolism pathways changed, mainly affecting auxiliary activities and lignin breakdown due to permafrost thawing. These findings highlight the importance of monitoring High Arctic vegetation expansion, as it may impact C degradation and greenhouse gas emissions more than permafrost thaw alone.

Abstract. Global warming causes thawing of permafrost, leading to landscape changes and infrastructure damage, problems that have intensified worldwide in all permafrost regions. This study numerically investigates the impact of different thermal stabilization methods on preventing or delaying permafrost thawing. To test different technical methods, an alpine mountain permafrost site with nearby infrastructure is investigated. Model simulations represent the one-dimensional (1D) effect of heat fluxes across the complex system of snow–ice–permafrost layers and the impact of passive and active cooling, including engineered energy flux dynamics at the surface. The results show the efficiency of different passive, active and combined thermal stabilization methods in influencing heat transfer, temperature distribution, and the seasonal active-layer thickness (ALT). Investigating each component of thermal stabilization helps quantify the efficiency of each method and determine their optimal combination. Despite providing efficient cooling in winter, passive methods are less efficient, as the ALT remains over 1 m. Conductive heat flux attenuation alone takes several years to form a stable frozen layer. Active cooling, when powered by solar energy, decreases the ALT to only a few decimetres. The combination of active and passive cooling, together with conductive heat flux attenuation, performs best and allows excess energy to be fed into the local grid. The findings of this study show the evolution of ground temperature and permafrost at a representative alpine site under natural and thermally stabilized conditions, contributing to understanding the potential and limitations of stabilization systems and formulating recommendations for optimal application.

Threshold-governed insulating and cooling effects of snow cover on alpine permafrost: evidence from the Qinghai–Tibet Plateau

The Canadian road map for Small Modular Reactors (SMRs) details that possible uses for SMRs includes providing electricity to remote communities. Many of the communities in the Canadian Arctic use diesel fuel generators to provide electricity. SMRs provide a possible future alternative to the combustion of fossil fuels in these communities. This has been done before by the United States Army Nuclear Power Program (ANPP) and Russia currently uses two SMRs to supply electricity in the Arctic. For power reactors in Canada, Derived Release Limits must be calculated using the N288.1 environmental compartment model. There is a compartment for soil in the N288.1 model that includes a few different soil types. However, the compartment is not suitable for soils that are underlain by permafrost (cryosols). In this paper we describe how the N288.1 soil compartment could be modified for permafrost conditions, and specifically those representative of the continuous permafrost zone, where 90-100% of the ground underlying the surface is perennially frozen. We provide example calculations using the modified version of the N288.1 soil compartment representative of conditions around Inuvik, a site in continuous permafrost. In general the specific calculations of the modified N288.1 standard tend to decrease the value of the P13 (air to soil) transfer factor.

Global warming increases the vegetation cover and leads to shifts in vegetation types in the Arctic. An increase in the vegetation cover might substantially enhance carbon dioxide (CO 2 ) emissions from northern permafrost soils, since root exudation of labile carbon and nitrogen can stimulate soil organic matter (SOM) decomposition via the rhizosphere priming effect. The current understanding of Arctic rhizosphere priming largely rests on soil incubation studies that simulate root exudation by adding various organic substrates in varying concentrations to soils. How the specific exudates of different plants influence rhizosphere priming is unclear as Arctic plant root exudate release rates and composition are largely unknown. Using targeted and non-targeted liquid chromatography–mass spectrometry, we compared the exudate composition and exudation rates of total organic carbon, 7 organic acids, 14 amino acids and 9 carbohydrates from three abundant and functionally different tundra plants ( Betula glandulosa , Alnus viridis and Eriophorum vaginatum ). While organic carbon and primary metabolites exudation were similar among the studied plants despite their different nitrogen acquisition strategies, distinct differences between the plant species were found in the overall root exudate composition. Between 80 to 94% of the root exudate metabolome was not shared among the three plants. Our findings indicate that a change in vegetation types across the Arctic will primarily alter the release of secondary plant metabolites into the soil and thereby could alter soil microbial processes. Our observations further suggest that previous laboratory experiments studying priming frequently oversaturated microorganisms with labile substrates compared to natural conditions; this highlights the need for more realistic priming studies. Our data on root exudation provide critical background information for improving laboratory experiments. • Total exuded carbon and primary metabolites were not different between plant species • The overall root exudate metabolome was different between plant species • Metabolome diversity is likely related to nitrogen uptake strategies • Previous incubation studies use substrate additions equalling several growing seasons • Mechanistic priming studies could be improved by observational root exudation data

Abstract Long‐term river monitoring of the Kuparuk River (North Slope, Alaska, USA) confirms significant increases in solutes that are indicative of active layer thickening due to thawing permafrost. However, there is no evidence of an increase in total dissolved phosphorus (TDP) or soluble reactive phosphorus (SRP), the nutrient that limits primary production in this and similar rivers in the region. Here, we show that Mehlich‐3 extractable iron (Fe) and aluminum (Al) in active layer soils impart high P geochemical sorption capacities across a range of landscape features that we would expect to promote lateral movement of water and solutes to headwater streams in our study watershed. Reanalysis of a recently published pan‐Arctic soils database that includes active layer and permafrost soil samples suggests that this high P sorption capacity could be common in other parts of the Arctic region. We conclude that soil minerals enhance P retention on hillslopes and propose pedogenic secondary Fe and Al minerals may continue to retain P in these soils and limit biological productivity in the adjacent river even as active layer thickening increases potential P mobility in the watershed. We suggest that similar interactions may occur in other areas of the Arctic where comparable geochemical conditions prevail.

The process of thermostabilization of thawed permafrost soils using seasonally-operating cooling devices can take a significant amount of time (up to several years). In certain soil and hydrological conditions, this leads to frost heaving of the subgrade foundation with a fairly long period of heave manifestation on the railway track. This paper describes a large-scale laboratory experiment conducted to model the thermostabilization of soils with seasonally-operating cooling devices. The purpose was to determine the empirical relationships between the magnitude of frost heaving in clay soils and their type and freezing rate. The experiment results show significant frost heaving of the soil mass during its thermostabilization by seasonal cooling devices. An empirical relationship was obtained for the volumetric frost heaving coefficient of clay soils with a plasticity index from 5 to 14, as a function of the radial freezing rate near the cooling device. This relationship is recommended for use in designing the thermostabilization of railway subgrade foundations in permafrost regions to quantitatively assess potential subsequent frost heaving deformations and to adopt compensating design solutions.

Relevance. Soil salinization is one of the major contributors to land degradation, which leads to changes in microbial and biochemical properties of soil, loss of biological diversity, desertification and disruption of ecosystem functioning in general. This article presents the results of studying the processes of technogenic salinization of soil cover in the north taiga landscape province within the continuous permafrost zone based on the example of mining area of the primary diamond deposits in Western Yakutia in the Yakutsk diamondiferous province (Alakit-Markha kimberlite field). Aim. Study of soil salinization processes in diamond mining within the continuous permafrost zone and identification of the causes for technogenic pedohalogenesis development. Methods. Major cations and anions, pH were determined in water extract (1:5), soil organic matter was determined using photoelectric colorimetric method. The total of toxic salts was calculated. Statistical analysis was conducted in Statistica10 program. Map-schemes of area distribution of soil salinization and totals of toxic salts were plotted using Surfer-13 program by kriging interpolation method. Result and conclusions. It was established that the processes of technogenic soil salinization due to diamond mining have acquired an areal character, being confined to the mining and processing facilities of the processing plant. In the impact area of waste dumps, predominantly sulfate type of salinization is observed, with the prevalence of toxic salts such as Na2SO4, MgSO4 and MgCl2. A marker of tailing dumps impact includes occurrence of chloride type of salinization and toxic salts, such as Na2SO4, MgSO4 and MgCl2, NaCl. Soil profile of technogenically salinized soils is distinguished by the presence of evaporative, biogenic or permafrost geochemical barriers, which displays the specific nature of salinization processes.

Abstract. Western Siberian peatlands are among the largest peatland complexes in the world and play a crucial role in regulating the global climate. However, a lack of long-term, multi-proxy studies comprehensively examining the interactions between permafrost thaw and peatland ecosystems in Western Siberia hinders the ability to predict their response to future climate change. This research covers two centuries of the Khanymei peatlands history, situated within the discontinuous permafrost zone. In this study, a multi-proxy analysis (testate amoebae, plant macrofossil, pollen, micro- and macrocharcoal, loss on ignition) was conducted on two peat cores – one from a peat plateau and another from the edge of a thermokarst lake. We inferred peatland drying from the end of the Little Ice Age. The elevated peat plateau facilitated the aggradation of permafrost, which began to thaw in recent decades due to rising air temperatures, increasing peat moisture. The lake edge was the most dynamic part of the peatland, where more notable changes in hydrology, vegetation, and microbial composition occurred. Thawing led to significant Sphagnum growth and a shift in the testate amoebae community structure. We reconstructed the effects of permafrost thawing that resulted in a substantial but short-term and local increase in peat and carbon accumulation and an increased abundance of fungal communities. Our study reveals that thaw-induced terrain subsidence was subtle and spatially variable, yet these localized surface changes triggered complex hydrological, vegetational, and microbial responses, highlighting the nonlinear and multifaceted nature of permafrost degradation. The advantage of our research lies in the utilization of multi-proxy high-resolution palaeoecological techniques, enabling us to monitor even relatively minor permafrost transformations and identify early warning signals of climate-induced impacts on this invaluable ecosystem. We anticipate that further warming will contribute to the occurrence of these processes on a larger scale in Western Siberian peatlands, potentially significantly impacting ecosystem conditions and the global climate.