The carbon balance in forest soils (CBFS) was studied on the basis of the geostatistical process model “BIGIN” (Biosphere Greenhousegas Inventory). Warming in boreal forests in the baseline period (1990 ± 5 yr.) initiates a shift in the CBFS towards its decrease, i. e. CO₂ source. In the horizon “O”, the decrease in the CBFS is minus 101.4 MtC. The warming of the climate by 1.5 °C and 3 °C will cause a further decrease in the CBFS by 345.7 MtC and 691.4 MtC, respectively. In moderately warm forests, climate warming initiates the formation of a positive CBFS, i. e. CO₂ sink. In the horizon “O” of the soils of moderately warm forests, climate warming in the baseline period and in the future leads to the development of positive CBFS, i. e. CO₂ sink of 62.4 MtC, 212.8 MtC and 425.4 MtC, respectively. Positive changes in the CBFS in boreal and moderately warm forests in the studied range of climatic temperatures were noted in the horizon “A1” (7.3 MtC, 24.9 MtC and 49.8 MtC) and the horizon “Bh” (14.1 MtC, 48.0 MtC, 96.2 MtC). Climate warming initiates a total negative CBFS (minus 17.6 MtC). Further warming of the climate by 1.5 °C and 3.0 °C will lead to a decrease in the CBFS by minus 60.0 MtC and minus 120.0 MtC. In terms of CO₂-equivalent, this will amount to 4%, 13% and 27% of the total country annual emission in 2020. Negative CBFS is not an indicator of emission strengthening. The final conclusion about CO₂ source/sink can be made only when analyzing the forest ecosystem when conducting a coupled soil-stand analysis. The error in the estimation of the CBFS in the soil organic profile in the baseline period is ± 23.0 MtC at a confidence level of P = 0.67 and ± 47 MtC at a confidence level of P = 0.95. With an increase in temperature by 1.5 °C, the error will be ± 80.0 MtC and ± 160.0 MtC at confidence levels of P = 0.67 and P = 0.95 respectively. The magnitude of the error will be ± 160.0 MtC and ± 320.0 MtC at confidence levels P = 0.67 and P = 0.95 respectively with an increase in temperature by 3.0 °C.

The problem of pedo- and biodiversity of mire ecosystems under the long-term multiple anthropogenic impact was studied in one of the most intensively technogenically transformed areas of Shaturskaya Meshchera, adjacent to power station Shaturskaya in the north and stretching along the route Kerva – Dolgusha – Severnaya Griva. For more than a hundred years, mires in the Shatura area have been under the influence of drainage, peat extraction, fires, attempts to create agricultural land, secondary watering and pollution, resulting from the power station, transport, and settlements wastewaters. Currently, the bio- and soil diversity of secondary ecosystems has increased significantly compared to undisturbed mires. Instead of bog, in some cases there appeared secondary meadow, grass-shrub communities, small-leaved forests, and dry sparse areas. The remaining bogs experience stable eutrophication, which leads to the formation of mesotrophic and eutrophic phytocenoses and, accordingly, peat mesotrophic and oligotrophic secondary eutrophic soils. In addition, the proportion of eutrophic mires is slightly increased by the peat formation in shallow lakes, which at the initial stage of peat extraction were used for storing wood waste. The phenomenon of secondary oligotrophization of the disturbed bogs of Meshchera, noted in the literature, is not observed in the area under consideration due to a significant anthropogenic load. To preserve the local flora of oligotrophic bogs, marginal areas of flooded quarries and cofferdams with undeveloped peat deposits are of great importance. The increase in pedodiversity was facilitated by the agricultural development of drained peatlands for the cultivation of perennial grasses, which resulted in the formation of torfozems and agrotorfyano-gleyzems.

The study focuses on the possibilities of using photographs obtained using crowdsourcing technologies for the operational inventory of arable soils. The object of the study is the spectral reflectance of the open surface of arable soils of the test plots, measured using a HandHeld-2 spectroradiometer operating in the range of 325–1 075 nm, and their image in photographs taken with conventional cameras. Test sites are located in the Tula, Moscow and Tver regions. The soils of the test plots are sod-podzolic, gray forest, and leached chernozems. Based on the analysis of photographs of the surface and information obtained using a spectroradiometer, a set of spectral parameters in the RGB, YMC and HSI color systems, as well as their ratios (45 parameters), was calculated. These parameters were used to separate the analyzed soil types using classification trees. The accuracy of classification based on the results of validation varies from 63–100%. At the same time, the parameters of the HSI and YMC color systems turned out to be more informative than the parameters of the RGB color system. The established classification rules can later be used to determine the classification position of soils from images collected using crowdsourcing technologies.

The elemental composition and structure of humic acids in the soddy-podzolic heavy loamy soil of the Cis-Urals were studied during long-term application of organic, mineral and organo-mineral fertilizers under conditions of a long-term stationary experiment. Mineral fertilizers contributed to the formation of humic acids with increased content of aliphatic components, the ratio H : C = 1.45 and a high degree of oxidation (ω = 0.41). The low content of nitrogen in humic acids (from 2.0 to 2.6 at.%), with various fertilizer systems, is primarily due to its low content in the plant biomass of crops cultivated in crop rotation.The organic fertilizer system resulted in the enrichment of the structural aggregates of humic acids with aromatic groups and nitrogen. The high intensity of absorption of the >C=O group of carboxylic acids in the region of 1 717 cm^-1 and double bonds of carbon atoms at 1 627 cm^-1 confirms this position. Humic acids of the “manure 10 t/ha” and “manure 5 t/ha + equiv. NPK” have the largest number of carboxyl groups in their composition. The vibrations of the >C=O group of carboxylic acids are most weakly expressed in soil humic acids with a mineral fertilizer system. Organo-mineral fertilizer system demonstrates intermediate results in terms of the content of the main constitutional elements in humic acids. Mineral fertilizers application reduces the amount and thermal stability of the structural components of humic acids, thereby contributing to the degradation of the most stable part of macromolecule, which can lead to the loss of potential soil fertility. Тhe use of mineral fertilizers on sod-podzolic heavy loamy soil led to the enrichment of humic acids with aliphatic fragments, and of organic ones – increased the content of stable components of aromatic nature, but lowered their thermal stability. According to thermographic analysis the ratio of weight loss in the low-temperature zone and the weight loss in the high-temperature zone (Z) during long-term use of mineral fertilizers is 0.9, i. e. the proportion of components of aliphatic nature in the structure of humic acids increases in comparison with unfertilized or manure fertilized soil.

The genesis main directions of the Ishim steppe watershed plain soils depending on their economic use (arable land, forest belt, abandoned land) during the 1950s – 2020s were revealed. Within the studied region, soils were diagnosed on lands of different use. It is shown that the regional morphogenetic feature of all watershed plain soils is the tonguing of the humus horizon, which is reflected in their classification status by the allocation of a dark-tonguic subtype of the soils. Differentiation of the agrodarkhumus horizon into two subhorizons under the influence of plane-cutting processing was revealed in the agrozem, prevailing by area. The manifestation of postagrogenic transformation of soils occurring under forest belts and under deposits with herbaceous vegetation is determined. Postagrogenic soils are characterized by a granular structure, higher reserves of humus and total nitrogen in a layer of 0–20 cm compared to agrozems. In the soil of the forest belt, a coarse-humus neo-horizon was formed, which is not typical of steppe soils. The soil under abandoned for a long time grassland has signs of dark humus horizon progradation to a state close to a virgin one. The additional surface moistening of micro-subsidence soils causes them to have a higher humus content and its reserves in the 0–100 cm layer, deeper leaching of carbonates, the formation of a clay-illuvial horizon in the carbonate-free zone and prevents the formation of a gypsum horizon. The groundwater level raising in the modern period, which is a consequence of the mass plowing and functioning of impenetrable protective forest belts in the study area, caused the appearance of neo-hydromorphism in watershed plain soils and the formation of quasi-clay subtypes. The results indicate the regional specificity of the genetic properties of the Ishim steppe watershed plain soils that distinguish them from their European counterparts, as well as the influence of agrogenic transformation as an anthropogenic factor on them. This influence is reflected in the morphology of soils, their humus state, the nature of the carbonate and gypsum profiles, the processes of halogenesis in them and the variety of salt profiles.

Surveys were carried out in Kondopoga and Kostomuksha, where the main industries are pulp-and-paper making and iron ore mining and concentration, respectively. Samples were taken from the top 0–10 cm soil layer in sites belonging to different land use categories and the content of heavy metals (Pb, Cu, Zn, Ni, Co, Cr, Mn) in the samples was determined by atomic absorption spectrophotometry (Aqua Regia extract). In addition, subsidiary soil pits were made for sampling at 0–5, 5–10, and 10–20 cm depths. These samples were analyzed for physico-chemical properties and heavy metal content. The results showed a relatively low level of heavy metal pollution of soil in the mentioned towns. Surveys in Kondopoga revealed limited general-use areas containing some elements in concentrations exceeding Russian national maximum allowable (MAC) and tentative allowable (TAC) levels (Pb – 6x MAC, Cu – 9x TAC, Zn – 16x TAC), and with labile copper and zinc concentrations up to 2x–3x MAC. Soils of Kostomuksha exhibited relatively low levels of the analyzed heavy metals with concentrations generally not exceeding the regional background in all land use categories. It was only occasionally that pollutant concentrations (Pb, Ni, Cu, Zn) reached 1–2x MAC/TAC. The resultant data can be used in the monitoring of urban soils and for working out recommendations for environmental protection.

Forest litter under linden and pine forests was studied at the Forest Experimental Dacha of the RSAU–MAA named after K.A. Timiryazev. Despite significant differences in physical and chemical parameters between the litter formed under the conditions of different forest communities, the properties of sod-podzolic soils formed under both vegetation types are quite similar. The litter under linden forest has higher ash content, it is less acidic and contains almost 2 times more exchangeable bases, the content of hydrogen and nitrogen is higher by 0.82 wt% and 0.66 wt%, respectively. The litter of linden and pine forests, according to the atomic ratios H : C, C : N and the degree of oxidation, are equal to 1.82, 30.3, -0.92 and 1.64, 45.7, -0.71, respectively; the litter of linden forests differs from litter of pine forests in the higher content of aliphatic, nitrogen-rich, reduced organic compounds. In the litter of linden forests concentration coefficients of phosphorus and magnesium 1.2 times higher; of carbon, potassium and aluminium – 1.3 times higher; of calcium – 1.4 times higher; of nitrogen – 1.8 times higher, and of silicon – 3 times higher, than in the litter of pine trees. However, the concentration factor of manganese in the pine forest litter is 1.9 times higher compared to the litter of linden. According to the results of UV spectroscopy, water-soluble organic matter of pine forest litter, unlike water-soluble organic matter of linden forest litter, is more enriched by components of aromatic origin. This is evidenced by higher values of SUVA₂₅₄ and lower values of coefficients E2/E3 and E4/E6.