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In the framework of the implementation of the all-Russian climatic project "Carbon measurement test sites", reference soils of "Seven Larches" carbon supersite, which is a benchmark and the only monitoring site in the Artistic latitudes, were investigated. The morphological structure of representative soils was specified, and it was found that soils are classified as Cryosols of different types (Histic, Stagnic or Gleyic). The basic physico-chemical characteristics of the soils were studied. By means of elemental analysis and 13C NMR spectroscopy, the composition and molecular structure of humic acids from organic and mineral soil horizons were studied. The surface (organic) soil horizons are characterized by high values of H:C molar ratios (1.2–1.3), which indicates a lower degree of the molecular structure aromaticity of humic acids from organic soil horizons. Analysis of the molecular structure of humic acids by 13C NMR spectroscopy showed that humic acids of the studied soils are characterized by the predominance of non-substituted aliphatic (0–47 ppm) and aromatic (108–164 ppm) fragments. Mineral soil horizons are characterized by higher stabilization of organic matter (with lower SOC content—0.5–0.9%) and higher hydrophobicity of humic acid molecules. Comparison of the obtained results with previously published data on the structural and elemental composition of humic acids isolated from soils of similar genesis and geographical location did not reveal any significant differences between the data obtained by us and previously published data. Thus, for "Seven Larches" carbon supersite "reference" parameters of elemental composition of humic acids, their molecular composition and degree of stabilization of soil organic matter were identified. [ABSTRACT FROM AUTHOR]

Agriculture in Central Asia and in the Fergana Valley in general strongly depends on irrigation and drainage of agricultural lands. The Fergana Valley includes about 45% of the irrigated area in the Syr Darya River basin. Active use of irrigation in agriculture can lead to changes in the soil's natural composition, as well as pollution and changes in the soil's physical and chemical properties. Soil degradation in the process of irrigation can lead to a decrease in crop yields and, as a consequence, to a decrease in food security in the region. In this study, a comparative analysis of three main types of Calcisols (Dark, Light, and Typical) before (uncultivated soil) and after agricultural use (surface-irrigated agricultural soil) was carried out. Irrigation leads to increment of SOC stocks in Typical (from 113.8 to 126.3 t/ha) and Light (from 62.8 to 100.1 t/ha) Calcisols and to decreasing of SOC stocks in Dark Calcisols (from 160.1 to 175.3 t/ha). In general, the content of biophilic elements (SOC and TN) is lower in irrigated soils, and their distribution in the soil profile is close to the functional relationship (r2 0.98 to 0.99). In uncultivated Calcisols, the profile distribution of SOC and TN is more heterogeneous (r2 0.67 to 0.97). Changes in the humification processes of soil organic matter are also identified; in soils after irrigation the carbon ratio of humic/fulvic acids (CHA/CFA) is lower (<1) compared to their uncultivated counterparts (~1). The alteration of the soil water regime also resulted in transformation of the individual compositions of amino acids. All studied types of Calcisols are characterized by changes in particle-size distribution of soils especially in the number of the silt fraction (0.01–0.05 mm) and the difference between uncultivated and irrigated soils, 10–20%, which is associated with the processes of colmatage by accumulation of a fine fraction and replacement of sub-fractions in the fraction of sand. The highest concentrations of nutrients are characteristic of the upper soil horizons (P up to 231, K up to 2350 mg/kg), which indicate their pedogenic and agrogenic origins rather than inheritance from the parent material. Soil P and K availability is rather high, with non-labile forms prevailing, although of near reserve. The surface irrigation results in apparent accumulation of water-soluble Mg2+ (1.6–2.1 meq/100 g) and K+ (0.6–0.9 meq/100 g), but the cation of Ca2+ predominates in the base cations' composition, which is the most favorable in terms of soil agrogenic property formation. Data obtained will be useful for development of strategies for effective land use in arid, subtropical, overpopulated regions of Central Asia that have deficient water sources and intensive soil degradation. [ABSTRACT FROM AUTHOR]

Post-agrogenic transformation of fallow soils leads to changes in soil carbon content, the molecular composition of humic substances, and rates of organic matter stabilization, which can affect climate change on the planet. In this regard, we analyzed the molecular composition of humic acids isolated from natural and fallow soils in the southern Taiga zone of northwest Russia. Different-aged soils on fallow lands represent a model of soil transformation in time, and data on the transformation of soil humic acid molecular composition make a significant contribution to the understanding of soil organic matter stabilization aspect issues. In this case, the molecular structure of humic acids isolated from natural and fallow soils in northwest Russia was analyzed. To study the molecular composition of HAs, the elemental composition was analyzed, and 13C (CP/MAS) NMR spectroscopy of HAs isolated from different aged abandoned soils and soils of different types of use was carried out. The obtained data showed that with the increasing age of soils in the fallow state, there is an increase in the carbon content of humic acids as well as a decrease in nitrogen content. As a result of the increasing age of soils in the fallow state, there are dynamics in the content of aromatic structural fragments in humic acids: 34% for 40 years old, 28% for 80 years old, and 31% for 120 years old. This is due to changes in the precursors of humification and the further transformation of plant residues in the soil. Re-involved fallow land soils lead to an increase in the content of aromatic structural fragments in the composition of HA in relation to HA extracted from mature soils. The lowest content of aromatic structural fragments was observed in the humic acids of 130-year-old agricultural soil, which is associated with the long-term application of organic fertilizers. [ABSTRACT FROM AUTHOR]

The global climate crisis forces mankind to develop carbon storage technologies. "Ladoga" carbon monitoring site is part of the Russian climate project "Carbon Supersites", which aims to develop methods and technologies to control the balance of greenhouse gases in various ecosystems. This article shows the condition of soil and vegetation cover of the carbon polygon "Ladoga" using the example of a typical southern taiga ecosystem in the Leningrad region (Russia). It is revealed that soils here are significantly disturbed as a result of agrogenic impact, and the vegetation cover changes under the influence of anthropogenic activity. It has been found that a considerable amount of carbon is deposited in the soils of the carbon polygon; its significant part is accumulated in peat soils (60.0 ± 19.8 kg × m−2 for 0–100 cm layer). In agrogenically disturbed and pristine soils, carbon stocks are equal to 12.8 ± 2.9 kg × m−2 and 8.3 ± 1.3 kg × m−2 in the 0–100 cm layer, respectively. Stocks of potentially mineralizable organic matter (0–10 cm) in peat soils are 0.48 ± 0.01 kg × m−2; in pristine soils, it is 0.58 ± 0.06 kg × m−2. Peat soils are characterized by a higher intensity of carbon mineralization 9.2 ± 0.1 mg × 100 g−1 × day−1 with greater stability. Carbon in pristine soils is mineralized with a lower rate—2.5 ± 0.2 mg × 100 g−1 × day−1. The study of microbial diversity of soils revealed that the dominant phyla of microorganisms are Actinobacteria, Bacteroidetes, and Proteobacteria; however, methane-producing Archaea—Euryarchaeota—were found in peat soils, indicating their potentially greater emission activity. The results of this work will be useful for decision makers and can be used as a reference for estimating the carbon balance of the Leningrad region and southern taiga boreal ecosystems of the Karelian Isthmus. [ABSTRACT FROM AUTHOR]

For the first time, data on the emission of climate-active gases from soils of different types of use of the south taiga sub-zone were obtained. Soils of the boreal belt are key elements of the global carbon cycle. They determine the sink and emission of climate-active gases. Soils near large cities are a major carbon sink, in the face of climate change, soils from sinks can become a source of carbon and contribute significantly to climate change on the planet. Studies of FCO2 and FCH4 fluxes were carried out on the territory of the monitoring site "Ladoga" located in the southern taiga subzone in soils of land not used in agriculture, former agriculture lands, and wetlands. During the chamber measurements, a portable gas analyzer GLA131-GGA (ABB, Canada) was used. The chamber was placed on the soil, after which the concentration of CO2, CH4 and H2O in the mobile chamber was recorded. As a result of the study it was found that the lowest emission of carbon dioxide is characteristic of soils developing on the soils of wetland and is 0.64 gCO2/(m2*year). Which is associated with a high degree of hydrophobicity of the territory and changes in the redox regime. The highest emission of carbon dioxide is registered in soils on the land not used in agriculture and is 4.16 gCO2/(m2*year). This is due to the formation of predominantly labile forms of carbon in the soil, which can be relatively rapidly involved in the carbon cycle and affect the active emission of carbon from the soil. According to the data obtained on FCH4 emission from soils, it was found that soils of land not used in agriculture and former agriculture lands were net sinks, while soils of wetlands were characterized by CH4 source, the emission was from 0.05 to 0.83 gCH4/(m2*year). The results obtained indicate spatial heterogeneity and changes in the carbon cycle within the monitoring site "Ladoga", which are due to the change of plant communities and habitat type. Monitoring the release of important greenhouse gases in close proximity to major urban areas is an important task in the face of predicted climate change and increasing rates of urbanization. [ABSTRACT FROM AUTHOR]

Technogenic processes and agrodevelopment of the soil cover lead to significant transformations of soil chemical and biological properties. New methods of soil microbiology, including next-generation sequencing, allows us to investigate soil microbial composition in detail, including the taxonomy and ecological functions of soil bacteria. This study presents data on the taxonomic diversity of mature and anthropogenically disturbed soils in various ecosystems of Russia. Natural soils in the southern taiga (Leningrad region and Novgorod region), northern taiga (Komi republic), forest-tundra, and tundra (Nadym city and Salekhard city) were investigated using next-generation sequencing (16S rDNA amplicon sequencing). In each natural bioclimatic zone, anthropogenically disturbed quarry soils or agriculturally transformed soils were also investigated. It was found that Proteobacteria, Actinobateriota, Acidobateriota, Bacteroidota, Chroloflexi, Planctomycetota, Verrucomicrobiota and Firmicutes phyla were dominant in natural soils, with minor differences between agrosoils and mature soils. In the soils of quarries, there were revealed processes of declining diversity of microbiome communities and the replacement of them by bacterial communities, different from natural and agrogenic soils. Thus, the microbial community is the most sensitive indicator of anthropogenic soil amendments and can serve to assess the success of soil self-restoration after human intervention. [ABSTRACT FROM AUTHOR]

Simple Summary: Insects play a crucial role in the functioning of terrestrial ecosystems. Chemical pest control methods continue to dominate in addressing food security issues in Russia. However, competent research on the impact of pesticides on non-target insect species is critically lacking both globally and in Russia. The article highlights the challenges of studying the effects of pesticides on insects and the vulnerability of insects to pesticides in regions with harsh conditions. It calls for the development of new sustainable agricultural practices to ensure coexistence between pest control and sustainable development. Furthermore, the article emphasises the importance of a legal framework regulating pesticide use and discusses new successful methods of sustainable farming. These findings contribute to the progress of the research discipline by promoting sustainable agricultural practices and striking a balance between agricultural expansion and insect protection. The focus on the significance of sustainable agriculture in harsh conditions also has implications for other regions facing similar challenges. As the world's population continues to increase, ensuring food security becomes a major problem. This often leads to the expansion of agricultural production, even in harsh conditions and becomes a key problem for many countries, including Russia. However, such expansion may entail certain costs, including the potential loss of insect populations, which are vital for ecological balance and agricultural productivity. The development of fallow lands in these regions is necessary to increase food production and increase food security; it is important to balance this with protection from harmful insects and sustainable farming methods. Research into the effects of insecticides on insects is an ongoing challenge, and new, sustainable farming methods are needed to ensure that protection from harmful insects and sustainable development can coexist. This article discusses the use of pesticides to protect the well-being of mankind, the problems of studying the effects of pesticides on insects and the vulnerability of insects to pesticides in regions with harsh conditions. It also discusses successful methods of sustainable agriculture and the importance of the legal framework governing the use of pesticides. The article emphasises the importance of balanced development with insect protection to ensure the sustainability of agricultural expansion in harsh conditions. [ABSTRACT FROM AUTHOR]

The Chernevaya taiga is a unique ecosystem formed under the influence of a complex of geogenic and bioclimatic factors located in the foothill border of the southeastern part of Western Siberia. The combination of local climatic conditions and the composition of parent material led to the formation of specific soil conditions on the territory of these habitats. The soils of the Chernevaya taiga have unique morphogenesis. They have a thick podzolized horizon and are fertile, unlike the typical soils of the oligotrophic pine forests of Siberia; however, the microstructure of these soils is poorly studied. The purpose of the research is to analyze the micromorphological organization and microstructure of three types of soils in Western Siberia (two typical soils from the Chernevaya taiga (Greyzemic Phaeozem (Albic) and Albic Stagnic Luvisol (Ochric)) and one from oligotrophic pine stand (Eutric Protoargic Arenosol)). It was found that the soils of the Chernevaya taiga differ greatly from the background (zonal) soils of the region on both the macro- and microlevels. In the Phaeozems and Luvisols of the Chernevaya taiga, there are actively formed organomineral aggregates and the quantity of porous media is more than 50%. At the bottom of the podzolized part of the soil profiles, we noted illuvial processes and a sharp change in the type of microstructure. The presence of pyrogenic materials (charcoal) and coprolitic (vermicular) materials in the humus-accumulative horizon indicates a high rate of material transformation and high biological activity and bioturbation in the soil. The skeleton part of the Chernevaya taiga soils is represented by a quartz–feldspar base with an admixture of sericite; augite; biotite; and a minimal admixture of tourmaline, zircon, and glauconite. [ABSTRACT FROM AUTHOR]

Polar ecosystems are the most important storage and source of climatically active gases. Currently, natural biogeochemical processes of organic matter circulation in the soil-atmosphere system are disturbed in urban ecosystems of the cryolithozone. Urbanized ecosystems in the Arctic are extremely under-investigated in terms of their functions in regulating the cycle of climatically active gases. The role of urban soils and soil-like bodies in the sequestration and stabilization of organic matter is of particular interest. The percentage of gravimetric concentrations of organic matter in Arctic urban soils are almost always determined by the method of dichromate oxidation and are subject to extreme variability (from tenths of a percent to more than 90% in man-made soil formations), but the average carbon content in the surface soil horizons can be estimated at 5–7%. The surface humus-accumulative horizons are represented by a variety of morphological forms with the content of organic matter of various origins. The work also focuses on those forms of organic matter, the content of which is extremely small, but very important for the biogeochemical functioning of soils-polycyclic aromatic hydrocarbons and components of petroleum products, as well as labile forms of soil organic matter. We recommend that further studies of the organic matter system be conducted in urbanized areas since the carbon cycle there is severely disrupted, as well as carbon flows. The urbanization and industrialization processes in the Arctic are progressing, which could lead to a radical transformation of carbon ecosystem services. [ABSTRACT FROM AUTHOR]

The surface of mountain glaciers is a place of accumulation of various biogenic organomineral and mineral compounds. As a result of intensive mass deglaciation of glaciers due to climate change and anthropogenic activity, this material can significantly affect the transformation of the landscape in the periglacial zone. Thus, this work considers the contamination of the surface of the Arctic, Antarctic, and Caucasian glaciers by priority pollutants. Atomic absorption spectroscopy was used to analyze trace elements (Cu, Zn, Ni, Cd, Pb) from cryoconite deposits. It was revealed that the cryoconite dust on the Ray-Iz glacier (Polar Urals) has a high level of nickel contamination, which comes to the glacier from local rock materials as a result of their weathering. The lowest concentrations of trace elements are found in one of the Arctic plots located at Mushketov and Aldegonda glaciers, the Caucasus, and the Antarctic, which is due to their relatively low content in the composition of rocks and the relatively low contribution of long-range transport of matter to the polar regions. Contamination of moraine sediments in the periglacial zone can make a significant contribution to the formation of the soil cover of these territories, the pollution of water bodies near the glacier, as well as affect the quality of life of the people living in the immediate vicinity of the mountain areas. [ABSTRACT FROM AUTHOR]

The establishment of a network of monitoring sites (term in Russian—«carbon polygons») for monitoring climatic processes as well as the emission and deposition of carbon compounds in various ecosystems is one of the priority tasks in the field of climate and biosphere conservation in the world. This paper presents the results of the study of the soil sections of the «Ladoga» carbon monitoring site. Folic Podzol (Arenic) and Fibric Histosol were considered. These soils are widely represented in the southern taiga subzone and can be used as benchmark monitoring soil sections. As a result of the analysis of chemical parameters, it was revealed that Fibric Histosol and Folic Podzol (Arenic) are characterized by an acidic reaction of pH, pronounced podsolization, and peat accumulation. Fibric Histosol stores a significant amount of soil organic matter (SOM) up to 42.95 kgC/m2. In the analysis of the molecular composition of humic acids (HAs) extracted from the studied soils, it was found that HAs from Fibric Histosol were characterized by a relatively high content of aromatic structural fragments (27–41%), while in Folic Podzol (Arenic), aliphatic structural fragments prevailed (up to 70%). The increase of aromatic structural fragments in the HAs composition indicates the stabilization and conservation of SOM. The creation of a monitoring network will make it possible to identify the main trends of SOM accumulation, determine the conditions under which accumulation occurs, and calculate its contribution to climate change on the planet. [ABSTRACT FROM AUTHOR]

This article highlights the role of anthropogenic factors in the modern and stage-by-stage development of soils, using the meadow-marsh soils of Central Fergana as an example. Information on the anthropogenic evolution of desert subtropical soils under long-term irrigation is provided. Data on the component composition of readily soluble salts in soils are discussed. It has been revealed that marsh-meadow soils under the influence of long-term irrigation gradually evolve into the irrigated meadow-saz soils of deserts. It is necessary to organize and conduct monitoring, the results of which could be implemented for the selection of agricultural crops, the development of methods of their sowing and planting, and for development of soil protection methods. In the initial period of using hydromorphic soils for irrigation in desert landscapes, there is a decrease in humus and total nitrogen content. The agrogenic transformation of hydromorphic soils under long-term and intensive use leads to significant changes in a number of soil properties. Each region-specific, soil-climatic condition may have its own pattern of soil areal evolution which is closely linked with the geochemical landscapes and the dynamics of the soil fertility. It is therefore necessary to consider the trends of soil transformation and evolution to improve soil fertility. [ABSTRACT FROM AUTHOR]

The use of conservation agriculture (SWC—soil and water conservation) technologies is now becoming more and more necessary. For the soils in arid ecosystems, the problem of irrigation deficiencies has always been relevant, and clean fresh water is always insufficient to irrigate these agricultural lands. This paper provides a brief historical overview of the use of mineralized water sources in agriculture and their impacts on soils and plants (Triticum aestivum L.). The experiment involving wheat cultivation in saline soils irrigated with mineralized water was set for 3 years. The main chemical and physical–chemical properties of the agro-transformed solonchaks and mineralized water sources were investigated. According to the contents of mobile forms of N, P, and K, the soils were poorly supplied; after a series of irrigation phases, they remained the same. There were signs of the growth of mobile phosphorus in the variants where mineralized water sources were applied. Our results showed that under conditions of irrigation with water sources with mineralization rates of up to 2.8–3.5 g/L, the wheat yield increased by 1.5 c/ha compared to the control. The use of mineralized water for irrigation purposes will reduce the use of clean river water. [ABSTRACT FROM AUTHOR]

Agricultural development in northern polar areas has potential as a result of global warming. Such expansion requires modern soil surveys and large-scale maps. In this study, the abandoned arable experimental field founded by I.G. Eichfeld one century ago in Salekhard city (Russian Arctic), located in the polar circle, was investigated. Our aims were to assess the nutritional soil properties and their spatial variability. For spatial assessment and mapping, ordinary kriging (OK) and inverse distance-weighted (IDW) methods were employed. We found that due to long-term agriculture use, the soil cover was represented by a unique Plaggic Podzol (Turbic) that is not typical of the region. The soil was characterized by relatively low soil organic carbon (SOC) content, high acidity and a high content of plant-available forms of phosphorus in the humus-accumulative horizon. The results showed that some properties (pH H2O, pH CaCl2) were characterized by large-scale heterogeneity and showed clear spatial dependence. However, some properties (ammonium and nitrate nitrogen, basal respiration) showed a pure-nugget effect, presumably due to experimentation with fertilizer over a long period of time. [ABSTRACT FROM AUTHOR]

Microbial activity plays a crucial role in the development and formation of soil properties. The active and abandoned agricultural soils in the Arctic zone represent a valuable resource that can play a crucial role in providing food security in the northern regions. The reuse of abandoned land for agriculture will reduce environmental risks in the context of a changing climate. Therefore, there is a need for monitoring studies to assess changes in soil parameters after long-term abandonment (taxonomic diversity, agrochemical and physico-chemical qualities). In the study, we evaluated the taxonomic diversity of the microbiome in abandoned (postagrogenic) and pristine soils of the Central part of the Yamal region. In the process of taxonomic analysis, more than 30 different bacterial and archaeal phyla were identified. The formation of a specific microbiome associated with anthropogenic influence in post-agrogenic sites has been shown. Most common types of soil microorganisms in samples collected from pristine and postagrogenic soils were Firmicutes (average 26.86%), Proteobacteria (average 23.41%), and Actinobacteria (average 15.45%). Firmicutes phylum was found mainly in the agrocenoses soils, Proteobacteria were mainly described in the mature tundra soils, Actinobacteria in humid conditions. An increase in diversity indices in postagrogenic soils was shown. [ABSTRACT FROM AUTHOR]

Soil cover of the Earth is faced with intensive polychemical contamination. The pathways of the key pollutants are not investigated enough. Thus, the occasional transportation of soils to remote regions could serve as an informative tool for the elaboration of threshold levels of hazardous materials concentration. One of the most striking examples of such transboundary impact was the transfer of soils and grounds to the Antarctic stations Russkaya and Leningradskaya (before the implementation of the Madrid Protocol in 1991). Thus, the complex investigation of qualitative and quantitative composition of polycyclic aromatic hydrocarbons (PAHs) in soils of various genesis (transported from Eurasia and pristine) of Antarctic have been conducted by the method of high-performance liquid chromatography (HPLC) in a gradient elution mode. The variability of PAHs content was evaluated across landscapes: pristine (the Hudson Mountains and the Haswell Archipelago), contaminated soils (stations Myrniy, Druzhnaya 4 and Bellinshausen) and unique samples of former agrosoils transported by fly in-fly of polar staff from St. Petersburg to Antarctic for local polar greenhouses in the Soviet times, when it was not strictly prohibited. The selected objects of study allow us to not only estimate the degree of contamination of Antarctic soils and grounds, but to also make it possible to assess the rate of PAH degradation in Antarctic conditions. Both high molecular and low molecular PAHs are accumulated following intense anthropogenic activity (fossil organic fuel combustion). The PAHs pool is dominated by low molecular weight representatives (naphthalene, phenanthrene, fluoranthene, pyrene). In most cases, the highest concentrations of benz(a)pyrene does not exceed the Russian Threshold Standard rate, which is the strictest one in the world. The statistical analysis of raw data allowed us to conclude that the contamination of pristine soils of Antarctica across variable landscapes is at the very initial stage. However, we recorded extremely high levels of PAHs in the transported former agrosoils. We can assume that our data could be used as background levels for the elaboration of threshold concentrations of the PAHs for such an internationally managed region as Antarctica. [ABSTRACT FROM AUTHOR]

The study focuses on the ornithogenic factor of soil formation in Antarctic conditions. Since the traditional soil formation processes in Antarctic conditions are very limited, the relevance of studying the role of the ornithogenic factor is increasing. This article provides a comparative study of nutrient content and values of some physico-chemical parameters between ornithogenic and non-ornithogenic soils sampled at terrestrial ecosystems of the Antarctic oasis Bunger Hills (Knox Coast, Wilkes Land). The levels of key biogenic elements content have been estimated with special reference to ornitogenic factor of soil formation. A high content of available forms of phosphorus and potassium in ornithogenic and non-ornithogenic soils was found. According to the results of statistical analysis, we can see that the content of nutritional elements has a close significant correlation relationship (p<0.05). The analysis of variance showed that the content of available phosphorus and potassium varies weakly between soils of ornithogenic and non-ornithogenic genesis. The greatest variability depending on soil-forming processes is noted for basal respiration, pH and available forms of nitrogen. [ABSTRACT FROM AUTHOR]

This research looked at the state of soils faced with urbanization processes in the Arctic region of the Yamal-Nenets Autonomous District (YANAO). Soils recently used in agriculture, which are now included in the infrastructure of the cities of Salekhard, Labytnangi, Kharsaim, and Aksarka in the form of various parks and public gardens were studied. Morphological, physico-chemical, and agrochemical studies of selected soils were conducted. Significant differences in fertility parameters between urbanized abandoned agricultural soils and mature soils of the region were revealed. The quality of soil resources was also evaluated in terms of their ecotoxicology condition, namely, the concentrations of trace metals in soils were determined and their current condition was assessed using calculations of various individual and complex soil quality indices. [ABSTRACT FROM AUTHOR]

Dynamically developing urbanization causes a number of environmental effects, including those related to the chemical transformation of soils. Relatively less information about the urban areas of the Arctic and Subarctic zones, constructed mostly on permafrost and intensively populated areas can be found. By the example of the analysis of basic soil properties and concentrations of trace metals in the soils of the cities of Salekhard, Urengoy, Nadym, Novy Urengoy and Gaz Sale (the Yamalo-Nenets Autonomous District), as well as various functional zones within the cities, the relationship between the age of the cities, the level of anthropogenic pressure and the type of parent materials and the character of accumulation of metals in the soil profile of urban soils have been described. The direct correlation was found between the content of Pb, Cr, Ni, As and soil sorption characteristics. In young cities built on sandy sediments, there is less accumulation of heavy metals in the topsoil horizons. Relatively higher concentrations of Cu and Cd were noted in soils of industrialized cities, regardless of functional zones. The higher content of Cr, Ni, Cu, Zn, As and Pb has been registered in older zones also frequently used for residential purposes. The calculated values of the PI index for some functional zones of young cities show the medium and high content of heavy metals. The analysis of Igeo and PLI indices shows a large diversity both in relation to individual cities and their functional zones. Soil quality, in spite of the high level of anthropogenic load, was assessed as mostly satisfactory. [ABSTRACT FROM AUTHOR]

Urban soils are the most vulnerable component of the current terrestrial ecosystem. Due to the anthropogenic influence, various pollutants can accumulate in the soils and have a negative effect on the health of citizens. As a result of the degradation of permafrost landscapes, the disappearance of a number of natural ecosystems, as well as urban areas, is possible. In the course of the development of thermokarst processes, problems arise in the urban environment with the destruction of urban buildings and a decrease in agricultural areas. The ecosystem of Yakutsk city is located in the valley of the Lena River and represents the largest urbanized terrestrial biotope, located in the permafrost-affected bioclimatic and geogenic conditions. This work represents relevant datasets on the physico-chemical, toxicological and agrochemical state of soil cover components in various functional zones of the city. An 3excess of the maximum threshold levels for Zn was noted in the area of active mining within the city borders. From the data obtained of pollution state, the most polluted zone of Yakutsk city is the quarry complex located in relative proximity to the city. In other studied areas of the city, there is no excess of permissible threshold levels for trace elements. According to agrochemical analysis, in Yakutsk city, there is a relatively low content of available agrochemical elements in comparison with other cities located in the permafrost-affected zone. [ABSTRACT FROM AUTHOR]

Digital soil maps find application in numerous fields, making their accuracy a crucial factor. Mapping soil properties in homogeneous landscapes where the soil surface is concealed, as in forests, presents a complex challenge. In this study, we evaluated the spatial distribution of soil organic carbon stocks (SOC stock ) under forest vegetation using three methods: regression kriging (RK), random forest (RF), and RF combined with ordinary kriging of residuals (RFOK) in combination with Sentinel-2A satellite data. We also compared their accuracies and identified key influencing factors. We determined that SOC stock ranged from 0.6 to 10.9 kg/m 2 with an average value of 4.9 kg/m 2 . Among the modelling approaches, we found that the RFOK exhibited the highest accuracy (RMSE = 1.58 kg/m 2 , NSE = 0.33), while the RK demonstrated a lack of spatial correlation of residuals, rendering this method inapplicable. An analysis of variable importance revealed that the SWIR B12 band of the Sentinel-2A satellite contributed the most to RFOK predictions. We concluded that the RFOK hybrid approach outperformed the others, potentially serving as a foundation for digital soil mapping under similar environmental conditions. Therefore, it is essential to consider spatial correlations when mapping soil properties in ecosystems that are inaccessible for capturing the spectral response of the soil surface., (© 2023. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)