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The method of luminescent microscopy has been applied to study the structure of the microbial biomass of soils and soil-like bodies in East (the Thala Hills and Larsemann Hills oases) and West (Cape Burks, Hobbs coast) Antarctica. According to Soil Taxonomy, the studied soils mainly belong to the subgroups of Aquic Haploturbels, Typic Haploturbels, Typic Haplorthels, and Lithic Haplorthels. The major contribution to their microbial biomass belongs to fungi. The highest fungal biomass (up to 790 μg C/g soil) has been found in the soils with surface organic horizons in the form of thin moss/lichen litters, in which the development of fungal mycelium is most active. A larger part of fungal biomass (70-98%) is represented by spores. For the soils without vegetation cover, the accumulation of bacterial and fungal biomass takes place in the horizons under surface desert pavements. In the upper parts of the soils without vegetation cover and in the organic soil horizons, the major part (>60%) of fungal mycelium contains protective melanin pigments. Among bacteria, the high portion (up to 50%) of small filtering forms is observed. A considerable increase (up to 290.2 ± 27 μg C/g soil) in the fungal biomass owing to the development of yeasts has been shown for gley soils (gleyzems) developing from sapropel sediments under subaquatic conditions and for the algal-bacterial mat on the bottom of the lake (920.7 ± 46 μg C/g soil). The production of carbon dioxide by the soils varies from 0.47 to 2.34 μg C-CO/(g day). The intensity of nitrogen fixation in the studied samples is generally low: from 0.08 to 55.85 ng СН/(g day). The intensity of denitrification varies from 0.09 to 19.28 μg N-NO/(g day). [ABSTRACT FROM AUTHOR]

We present an empirical method of measuring geometric noise in matrix photoreceptors included in an intelligent system developed for detecting obstacles in the path of a train. A reference calibration field uses thermal images of crossties. Measurement of geometric noise sensitivity and dark current is based on selected levels of homogeneity in the reference image. The experimental results demonstrated the advantage of the proposed method compared to a conventional two-point calibration. [ABSTRACT FROM AUTHOR]

This paper considers regularities governing the formation of automorphic tundra soils on glacial loamy deposits containing relict organic matter mainly represented by very fine plant detritus. Drainage, microtopography, and cryoturbation activity are the major controls of the development of these soils. With an increase in drainage, the following pedogenetic trend is observed on the surface of yedoma (Ice Сomplex) areas: gleyzem-cryozem-cryometamorphic soil. The climate change in the Holocene induced quick transformation of topography and general landscape situation and promoted formation and development of cryogenic soil complexes in the considered territory. Upon the low intensity of pedogenesis, the features and properties of previous soil formation stages are often preserved in the soil profiles; these are: gleyzation, peat accumulation, and cryoturbation. [ABSTRACT FROM AUTHOR]

The role of cryogenic mass exchange in the distribution of the viable microfauna (ciliates, heterotrophic flagellates, and nematodes) in the profiles of cryoturbated cryogenic soils and in the upper layers of permafrost was revealed. The material for microbiological investigations was collected from the main horizons of cryozem profiles, including the zones with morphologically manifested processes of cryogenic mass exchange (the development of barren spots, cryoturbation, and suprapermafrost accumulation) and the zones affected by solifluction. The radiocarbon dating of the soil samples showed that the age of the organic cryogenic material and material buried in the course of solifluction varied from 2100 to 4500 years. Some zones with specific ecological conditions promoting the preservation of species diversity of the microfauna were found to develop in the cryozem profiles. A considerable part of the community (38% of ciliates, 58% of flagellates, and 50% of nematodes) maintained its viability in the dormant state, and in some cases, it could pass to the state of long-term cryobiosis in the upper layer of permafrost. [ABSTRACT FROM AUTHOR]

Only 0.35% (49,500 km 2 ) of Antarctica is ice-free. These areas are scattered around the periphery of the continent and in interior mountain ranges, making soil mapping difficult. Here we compile the results of mapping in five of the nine ice-free areas that account for 79% of the ice-free area on a reconnaissance scale and interpret the distribution of soil subgroups in Soil Taxonomy . Soils of Antarctica are contained in four orders, dominantly Gelisols (84%), 13 suborders, 27 great groups, and 76 subgroups. Forty-five percent of the soils of Antarctica are Orthels, Gelisols that show minimal cryoturbation and occur in dry landscape positions; 38% of the soils are Turbels showing cryoturbation and occurring in more moist landscape positions. Only 16% of the soils of Antarctica lack permafrost in the control section and are classified as Entisols (Gel-great groups), Inceptisols (Gelepts suborder or Gelaquepts), or Histosols (Gel-great groups). These soils occur almost exclusively along the western Antarctic Peninsula and at elevations below 30 m in the South Shetland Islands (SSI) and South Orkney Islands (SOI). Typic Anhyorthels are the dominant soil subgroup comprising nearly 15,340 km 2 , or 31% of the soils in Antarctica. These soils occur primarily in central and southern Victoria Land, but also occur in the Thiel and Pensacola Mountains and Shackleton Range, the Prince Charles Mountains, and the mountains of Queen Maud Land. Typic Haploturbels and Typic Anhyturbels occupy 14 and 13% of the soils of ice-free regions of Antarctica, respectively. Most abundant in central Victoria Land, they are common in most mountainous regions of Antarctica. The dominant soil processes of maritime Antarctica are cryoturbation, gleization, melanization, podzolization, paludization, and phosphatization. In coastal East Antarctica, the major soil processes are rubification, salinization, calcification, pervection, and gleization. The predominant soil-forming processes in the Transantarctic Mountains include rubification, salinization, desert pavement formation, and permafrost development. Measures of pedodiversity will be valuable in the selection of protected areas in Antarctica. [ABSTRACT FROM AUTHOR]

The efficiency of mass transfer in the separation of hydrogen isotopes by water distillation in the presence of urea as a separating agent has been estimated. Experiments have been performed for vapor–liquid and vapor–aqueous salt solution systems under conditions with independent flows. Two regimes of mass transfer have been considered: the first one when the operating concentration of deuterium in the liquid phase is lower than that in equilibrium with the vapor (xD< ) and the second one when it is higher than that in equilibrium with the vapor (xD> ). A substantial difference in the number of theoretical separation stages for these regimes has been found. At xD> , in the presence of urea as a separating agent, the number of theoretical separation stages is three times lower than that for the vapor–water system. Thus, in the distillation of the hydrogen isotopes of water, urea hinders the transport of deuterium from the liquid phase to the vapor phase, forming nonvolatile complexes with water molecules that contain deuterium. [ABSTRACT FROM AUTHOR]

A single separation effect between deuterium and protium was studied experimentally under phase equilibrium conditions in a water vapor–water salt solution system at temperatures from 59 to 94°C. The vapor–liquid equilibrium was investigated by the dynamic method in a Bushmakin device. The presence of urea in water significantly increased the separation coefficient αL–V in the given temperature range. The characteristic increase in the relative volatility coefficient of the hydrogen isotopes of water remained unchanged at lower temperatures in the presence of salts. The isotope salt effects, both negative and positive, increased with the salt concentration. [ABSTRACT FROM AUTHOR]

Environmental disturbance is an unpreventable consequence of human impact after exploration and research station management in Antarctica. Environmental pollution may directly influence Antarctic mycobiota. However, information about the effect of anthropogenic factors on microscopic fungi at extremely low temperatures is insufficient. This work compared the abundance and the species diversity of mycelial fungi from soils of six Russian research Antarctic stations—Bellingshausen, Progress-2, Druzhnaya-4, Molodezhnaya, Novolazarevskaya and Oasis−affected by various anthropogenic impacts (operation of tracked and wheeled vehicles, storage and use of petroleum products and petroleum leakage sites) with that from their background analogues. New data were obtained on the taxonomic diversity of mycelial fungi from Antarctic soils with different anthropogenic loads. Cultural, morphological and physiological studies of 142 isolated strains of mycelial fungi were supplemented by molecular-biological research into sterile mycelium strains and those with vague morphological characters. This contributed not only to the verification but also to a significant increase in the number of taxa of mycelial fungi isolated from low-temperature ecotopes. Leotiomycetes and Dothideomycetes were found to be the most dominant classes in the studied samples. It was shown that several ecological groups of micromycetes could be isolated among the mycobiota of the investigated habitats, the abundance and species composition of which changed differently under the influence of anthropogenic factors. The current results highlight that microbiota changes in human-affected soils can serve as an indicator of the state of low-temperature ecotopes in general. [ABSTRACT FROM AUTHOR]

See the retraction notice BIO Web of Conferences 84, 00001 (2024), https://doi.org/10.1051/bioconf/20248400001

The study of microbial complexes in organo-accumulative horizons of Antarctic soils (Cryosols, Leptosols) at the Larsemann Hills and Schirmacher oases and on King George Island has been carried out by the fouling glass method. This method allows one to study the taxonomic composition of microorganisms, features of their morphology, inter-organism interactions, and spatial organization of the complex of microorganisms, as well as to simulate the processes of colonization of mineral surfaces. The investigated microbial complexes can be subdivided into four groups with respect to dominant microorganisms: (1) diverse microbial complexes of King George Island with a considerable portion of diatoms among algae and with a predominance of mycelium in the fungal biomass; (2) complexes of lichen–moss, moss, and algal–moss associations in lake basins with a greater proportion of eukaryotic and coccoid cyanobacteria and with mycelium and sporous forms of micromycetes; (3) complexes of moss and algal–moss associations in the bottoms of wet valleys with a higher proportion of filamentous cyanobacteria and with the absence of fungi, or their presence in the form of short chains of chlamydospores; and (4) hypolithic microbial complexes of rock baths in dry rocky habitats, where the fouling of glasses did not take place. The microbial complexes in different glass samples taken in February–March in different years proved to be at different stages of development. Microscopic mycelium of fungi was not abundant in all algae and moss associations; in some, it was practically absent. Among algae, not cyanobacteria, but eukaryotic algae dominated in a number of habitats: diatoms, green algae, and streptophytes. The totality of the complex features indicated the extremity of the habitat: one morphotype of melanized fungal mycelium dominated in a particular sample; there was no diversity of spore forms, which indirectly indicates a low taxonomic diversity of fungi; multiple chlamydospore formation and microcycles of development were common. Among cyanobacteria, brown and reddish coloration was often found, and the formation of biofilms on glasses was limited to microcolonies, while algal biofilms abundantly covered the soil of the studied horizons. Apparently, extended biofilms were formed over time exceeding the exposure time of the glasses. Hypolithic communities did not colonize new habitats (glasses) for several years of exposure, unlike the bottoms of hydromorphic valleys and lake basins in oases (glasses overgrown in a year) and King George Island (glasses overgrown in 10 days). [ABSTRACT FROM AUTHOR]

Retrogressive thaw slumps (RTS) are an important landform of rapid permafrost degradation in regions with very high ground ice contents. RTS mobilize significant amounts of sediment, meltwater and organic carbon and impact downstream hydrological systems by directly affecting topography and water quality. The term megaslump has previously been coined for RTS exceeding 20 ha in size. The Batagay megaslump in the Yana highlands of NE Siberia with an area of 87.6 ha (in 2023, including the bowl-shaped part and the erosional outlet) has been identified as the largest megaslump on Earth. We use very high resolution remote sensing from satellite data and drones, geological structure modeling, and field data to assess how much and what material is thawed and mobilized in the Batagay megaslump. The total volume of permafrost thaw and material loss from the Batagay RTS amounts to about 1 million m3 per year. The material is by one third composed of thawed sediments and by two thirds of melted ground ice. About 4000 to 5000 tons of previously permafrost-locked organic carbon is released every year. Organic carbon content has been measured as Total Organic Carbon (TOC) of sediments and as Dissolved Organic Carbon (DOC) of ground ice. From its formation in the 1970s until 2023, the Batagay RTS – due to thermal denudation and headwalls retreat – mobilized a total volume of about 34.7 million m3 of which 23.4 million m3 were melted ground ice and 11.3 million m3 were thawed deposits including a total of about 169,500 t organic carbon. With these rates of sediment and carbon mobilization, the Batagay megaslump is not only a prominent local feature of rapid permafrost thaw, but offers excellent conditions to study rates and mechanisms of rapid permafrost degradations and to calculate the stock and release of, e.g., organic matter. • 3D geological modeling allowed estimating the Batagay megaslump material flux. • The megaslump mobilized ca. 35 million m3 since initiation in the 1990s. • Since 2014, the annual mobilized volume amounts to ca. 1 million m3/year. • About ⅔ of the total material volume was ground ice and ⅓ was permafrost sediments. • Organic carbon release amounts to 4000 to 5000 tons per year. [ABSTRACT FROM AUTHOR]

The role of ornithogenic factor in the formation of soils and soil cover patterns in continental and maritime Antarctica is considered. The results of long-term soil studies at key sites in coastal oases of East Antarctica (Larsemann Hills, the Haswell Islands) and on the Subantarctic islands (King George Island, Livingston Island, the Argentine Islands) are summarized. The influence of the penguin rookeries on the morphology and physicochemical properties of soils is shown. These rookeries determine the vast spatial zones of biogeochemical influence on the environment around themselves. Special attention is paid to the phenomenon of ornithochory, which is maintained by the flying seabirds (skuas, albatrosses, terns, petrels, etc.) and is manifested in redistribution of vegetation, soil material, and meso- and microbiota to the areas that were previously free of vegetation and soil cover (periglacial areas, fresh moraines, rocky outcrops, etc.). [ABSTRACT FROM AUTHOR]

The cryogenic mass-exchange processes affect the content and distribution of organic matter in Cryosol profiles enriching the mineral horizons with organic matter. It has been shown that the mineralization capacity of organic materials in Cryosols is low even under optimum conditions of temperature and moisture. Despite the significant variation in the microbial biomass content, the general pattern of its distribution in the profile with a maximum in organic horizons and a minimum in mineral horizons is preserved in all studied profiles. The fraction of the microbial biomass carbon (Cmb) in the total organic carbon is less than 1%. The microbial respiration quotient (Qr) varies from <0.1 to 0.3. The most significant influence on the microbial biomass and changes in its respiration activity in the profiles of Cryosols is recorded for the contents of total organic carbon (TOC) and total nitrogen (TN) and for the soil porosity. [ABSTRACT FROM AUTHOR]

The analysis of about 200 samples taken from 42 permafrost-affected soil profiles was carried out on four key sites in different regions of cryolithozone (West Siberia, Central, North, and North-East Yakutia) characterized by different active layer depths and soil lithology. The aim of the study was to determine the influence of different processes of cryogenic mass-exchange on the redistribution and accumulation of major pollutants such as petroleum products, acid-soluble forms of trace elements, polycyclic hydrocarbons, and technogenic radionuclides transferred via atmospheric transport or after the local anthropogenic impact in different soil horizons of Cryosols and in the upper layers of permafrost. Samples were analyzed using modern precise techniques (direct γ-spectrometric measurements with Ge(Li) and NaI(Tl) detectors; fluorometric method; reversed-phase high-performance liquid chromatography; spectrofluorimetric detection; atomic absorption spectrometry with flame atomization). The study has shown that processes (cryoturbations, frost heaving, gelifluction along with fluvial processes) that strongly affect Cryosols' profile structure can also lead to the active migration and accumulation of local and global pollutants in the middle and lowermost suprapermafrost soil horizons. The accumulation of some pollutants in suprapermafrost horizons of cryogenic soils and in the upper layers of permafrost (in particular, petroleum products and mobile forms of trace elements) can be associated with a combination of factors, such as the relatively light particle size distribution, relatively weak manifestation of cryoturbation processes, and low thickness of the active layer (about 40-60 cm). The integral calculation of the geoaccumulation index values has shown that all of the groups of human-affected soil horizons are moderately to extremely polluted by petroleum hydrocarbons (and at a relatively lower level by trace elements) and the maximum pollution stands for the suprapermafrost horizons as well as in cryoturbated or buried fragments of organogenic matter in some cases. The maxima of the heavy PAH content in permafrost-affected soils can be confined to horizons enriched with anthropogenic inclusions and artifacts (for example, construction slag, coal) and to individual horizons of soils buried as a result of both cryogenic and alluvial processes. The specific activity of the technogenic radionuclide cesium in cryogenic soils revealed its association mainly with the surface organogenic and organomineral horizons of the studied profiles and rarely observed in the cryoturbated fragments of these horizons in the middle and suprapermafrost layers of soil profiles. The necessity of the complex analytical assessment of the permafrost-affected soils has been revealed especially in case of studying of the ecological state of the anthropogenically affected Cryosols., (© 2022. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Comparative investigation of the soil contamination by polycyclic aromatic compounds (PAC) has been performed on examples of three polar stations of the Antarctic Peninsula. Data obtained are especially interesting for the Ukrainian Antarctic station "Academician Vernadsky" were no such investigations were performed since the technogenic spill of the hydrocarbons in 1992. Results of investigations permit to establish the values of the total background level of the PAC pollution as the base for the further monitoring of anthropogenic contamination. The data of analysis of soils from the all ecological zones of Point Thomas oasis (Polish Station "Genrik Artstovskiy") show the PAC homogenous background pollution to be similar to identified at the Galindez Island (the region of the station Academician Vernadskiy). Local pollutions are revealed in some areas of the Galindez Island. At the same time results of the investigation of the soils pollution from the various areas of the Fildes Peninsula (the station Bellingshausen.) show the absence of clearly pronounced contrast between the background and "hot points" that is likely related with the even pollution of the Peninsula. There was demonstrated the necessity of the development of regional standards and the establishment of a local background concentrations of PACs within the Antarctic Peninsula. At the same time, significant differences between the contamination of soils taken from the stations"Academician Vernadsky" and "Bellingshausen", apparently are associated with a lesser capacity of soils on the island Galindez that in the commensurable pollution creates greater concentrations in an investigated sample of the soil. There was shown the necessity of the development of the regional standard and the establishment of a local background concentrations of PACs within the Antarctic Peninsula.