When solving the problem of the relationship between landscape space and landscape time, we often use the relationships between tree growth and climatic parameters to indicate changes in landscape functioning. The article analyzes the influence of climatic factors during recent 140 years on the growth of Siberian stone pine (Pinus sibirica) on frost mounds in the north of Western Siberia within bog landscapes of the northern taiga subzone. Dendrochronologies were constructed for 47 sampling sites located on various types of frost mounds. It was found that most of dendrochronologies correlate with each other, although the mounds are significantly different. Sampling sites adjacent to thermokarst sinkholes are the least consistent with the modal dendrochronology. It was found that there is no reliable relationship between mean annual temperatures and tree growth; the most considerable tree growth is observed in years with high May air temperatures. The ideal conditions for tree growth are cold winters with little snow and warm and humid summers. It was found that during periods with abnormally high air temperatures tree growth decreases. It happens due to the degradation of permafrost mounds and the increasingly thicker seasonally thawed layer. So the depth of soil water decreases, and the upper soil horizon dries up.

The paper presents the results of studying the distribution of methane in near-bottom waters and bottom sediments in different parts of the Vygozero reservoir, which were identified in accordance with the morphology of the basin and various conditions of bottom sediments formation: South-Eastern area, former flooded bogs, river mouths and the Bobrovoe Lake; Central area, i. e. the Vygozero Lake before flooding; and the Northern region in which currents are influenced by the Segezha River, and which is affected by waste waters from the Segezha Pulp and Paper Mill.
It was found that the methane content in the Vygozero reservoir is comparable to the data for other temperate water bodies. The non-uniform gas distribution is shown (from 0,75 · 10–³ to 1,7 · 10–³ mg/l in bottom water and from 0,1 to 1,2 mg/l in bottom sediments). The highest concentrations were recorded in the South-Eastern region, and the minimum in the Northern region, which is determined by both qualitative composition of organic matter (the fulvate humus in the South-Eastern region, in contrast to the predominance of humic acids in other regions, as well as the higher sulfur content in the sediments of the Northern region) and thermal conditions (the warmer shallow South-Eastern region).
The rate of gas inflow from bottom sediments varied from 6,36 to 14,16 mgCH₄/(m²·day) depending on the region: the maximum was recorded in the South-Eastern part, and the minimum in the Northern part of the reservoir. The total methane flux from bottom sediments was more than 11 tons/day. We proved that the spatial heterogeneity of methane distribution in the reservoir depends on the morphology of the basin, the uneven distribution of river runoff and actual anthropogenic load, and is also largely determined by the history of the reservoir, namely, the burial of organic matter of different genesis during the formation of a new reservoir bed after its flooding.

Estuaries are important sources of methane (CH₄) to the atmosphere. Estimates of the emission of this greenhouse gas are necessary to determine its contribution to the global atmospheric budget. The paper discusses the results of measuring the temporal dynamics of CH₄ concentration and its emission at the atmosphere- water boundary in the Chernaya River estuary, influenced by the seiche waves. The hydrochemical studies together with hydrophysical measurements were carried out in 2021 winter, spring and summer seasons using the RCM 9 LW (Aanderaa) multi-parameter sound. High rates and a wide range of daily-measured CH₄ concentration changes in water of the Chernaya River estuary was shown which correspond to the dynamics of recorded wave processes. The calculated periods of hydrological parameters oscillation were 45, 19–21, 14–17 and 9 min. The trend of CH₄ concentration variations was consistent with salinity changes: higher CH₄ values correspond to fresh waters, and lower values to seawaters. The highest correlation was between the values of СН₄ concentration and water temperature (R = 0,61), and the content of dissolved oxygen (R = –0,61). The calculated CH₄ flux from water surface to the atmosphere for different seasons was in the range from 71 to 1680 μmol/m²· day. Balance estimates showed that the turnover time of dissolved methane in the estuary of the Chernaya River, i. e. the ratio of methane content in 1 m³ to the sum of its fluxes from the bottom and into the atmosphere, did not exceed one day for the selected conditions. It was shown that high rates and a wide range of changes in CH₄ concentration in areas subject to wave processes, as well as the patterns of such changes, are of high importance in the context of assessing methane fluxes into the atmosphere.

The study deals with comparative analysis of independent reconstructions of temperature regime during the cold period of the largest in the Russian Arctic Late Pleistocene glaciation (18–21 kyr BP), based on the data of isotopic analysis and the results of numerical modeling. The study used the data of numerical experiments of PMIP3 climatic models of the Earth system, and the results of temperature reconstruction based on the isotopic composition of syngenetic ice wedges (δ18O). It is shown that in some areas there are significant differences in temperatures reconstructed from the isotope data and obtained from the modeling data. In particular, it was found that the difference in simulated and reconstructed temperatures decreases with distance from the hypothetic ice sheet, which allows concluding that the accuracy of the ice sheet location in the models is significant for the final simulation results.
In particular, different approaches in paleoclimatic studies lead to rather different estimates of the area of continental and shelf ice of the epoch. The area of glaciers and their properties are taken into account in climate models in the process of calculations. Our investigation shows that high-quality modeling definitely requires refining the paleoreconstructions based on proxy climate data.

The study presents a modern quantitative assessment of the content of organic carbon in Russian soils, taking into account their huge variety, and reflects the understanding of individual factors regulating and controlling the content of organic carbon in soils of the country. The paper gives the results of three-dimensional modeling of organic carbon content in soils at several standard depths (0–5, 5–15, 15–30, 30–60, 60–100 cm) for the territory of the Russian Federation with 500 m spatial resolution using the ensemble machine learning. Automated predictive mapping was based on 4 961 soil horizons from 863 soil profiles, as well as on the extensive set of spatial information, including bioclimatic variables, digital elevation model and its derivatives, and the long-term averaged time series of MODIS data. An ensemble machine learning algorithm (stacking, stacked generalization and stacked regression) was used to build models of spatial and vertical distribution. The accuracy of obtained cartographic models was assessed using spatial cross-validation. The results of spatial cross-validation show lower accuracy: the coefficient of determination is 0,46, CCC – 0.63, logRMSE – 0,88 (RMSE – 1,41 g/kg) compared to randomize (R2 cv – 0,68, CCC – 0,81, logRMSE – 0,68 (RMSE – 0,97 g/kg)).
The proposed quantitative assessment is fully automated and makes it possible to reproduce the modeling and refine the results as new soil data are obtained.

The paper presents the results of studying the urban heat island formation in winter under the stable atmospheric stratification for small Arctic and subarctic cities (case study of the Nadym city). As a result of three measurement campaigns using contact and remote measurements, information was obtained on the intensity and vertical extent of the urban heat island. Simultaneous measurements of temperature and wind speed profiles within and outside the city showed that, with a strongly stable stratification, a mixed boundary layer is formed in the city with close to neutral stratification and a height of about 50 m. To explain the revealed phenomenon, LES modeling of the turbulent flow was carried out. A turbulent flow typical for winter conditions in a quasi-stationary, stable-stratified boundary layer above a flat surface was used as a flow approaching the city. A real 3D model of urban built-up area was used, obtained from the OpenStreetMap database and refined using the ArctiсDEM data and by visual evaluation of building height. The simulation results confirmed the formation of a mixed layer in the urban environment and showed that mechanical mixing of a stably stratified atmosphere is an important mechanism of urban heat island formation at the surface. This is confirmed by the fact that, according to calculations, the turbulent kinetic energy in the city is more than 10 times higher than the TKE outside its borders. The main source of TKE in the city is its shear generation at the height of buildings as they are flown around. Experimental studies and theoretical calculations have confirmed the existence of a pronounced urban heat island in small polar cities under stable stratification and for the first time made it possible to estimate the height of its vertical development.

Asymmetry is a fundamental property of cities as geographical objects. Asymmetric features of a city are associated with the contrast of its natural basis. Landscape contrast lines correspond to belts with increased resource diversity and are lines of concentration of cities. The nodes of contrast landscape boundaries are often the locations of cities. The nodal boundary position of a city leads to the sector-mosaic structure of surrounding area. The high landscape diversity at the location contributes to the aesthetics of a large city and is expressed in higher concentration of tourist sites in its surroundings. The pattern of main natural boundaries, or landscape matrix, in the space of a city and its surroundings form the basis for asymmetry properties of the city and its complementary region. Asymmetric features of the city are particularly characteristic for its landscapetypological plan, functional-planning scheme, engineering-geological structure, microclimatic zoning, as well as biological and soil conditions.

The work continues the study of the causes of climatic changes in the Moscow region basing on the observations of the MSU Meteorological Observatory. Long-term dynamics of the main climate-forming factor, i. e. the radiation regime of the atmosphere, was analyzed. During the 65 year observation period in Moscow, significant trends were noted for all radiation parameters of the atmosphere, most pronounced in winter. The average annual values of radiation, long-wavelength balances and soil surface temperature increase by 26, 16 and 49% respectively, and their winter values by 73, 41 and 34%. In the 21^st century, the decrease in aerosol turbidity of the atmosphere, the increase in direct and the decrease in scattered radiation have intensified. The rate of increase in the long-wave and radiation balance, as well as in the soil surface temperature, has almost doubled. In the absence of significant volcanic eruptions, the “greenhouse effect” of cloud cover has become a principal natural factor. The anthropogenic component of aerosol turbidity has significantly decreased in recent years, which is associated with a number of measures taken by the Moscow government to improve the state of the environment in the city. The anthropogenic influence on the radiation regime in the city manifested itself in higher long-wave fluxes, which led to increased intensity of the “heat island” in the 21^st century.

Natural characteristics of the area historically influenced the character of territory development and settlement. A most important landscape differentiation factor of the territory of the Udmurt Republic is the alternation of Quaternary deposit types, which greatly complicates the zonal change of soil types. Depending on soil fertility within each natural landscape agricultural and forestry types of nature management were formed. The aim of the study was to confirm the relationships between the types of Quaternary deposits as a substrate for soil formation and settlement indicators as indicators of nature management types. The relationships were stu died within Professor V.I. Sturman’s landscape zoning scheme of the Udmurt Republic. To determine a character of the relationships, Calculation of pair correlation coefficients was the principal method of finding the nature of relationships under study. The research proved that landscapes with higher proportion of aeolian, marsh and alluvial deposits are characterized by lower population and settlement density, low density of the road network, and higher average population of rural settlements. The opposite trend for all the indicators mentioned above is observed in landscapes with higher proportion of eluvial, eluvial-deluvial and deluvial-solifluction deposits. It was proved that close relationship between the types of Quaternary sediments and settlement indicators varies in different parts of the republic, against the background of zonal climate changes and azonal relief changes. It turned out that the distribution of geographically incompatible aeolian and eluvial-deluvial deposits, which have the largest distribution areas, has the greatest impact on the settlement pattern. It was found that for the period from 1970 to 2020, the strength of most studied relationships decreased against the general trend of population outflow from rural areas to cities. This was due to the “low base effect”, which leveled off territorial contrasts in the population settlement within the landscapes of the Udmurt Republic.

Against the background of ongoing migration outflow of rural residents to cities, the process of city dwellers transfer to rural areas is hardly noticeable, particularly if they do not change their city registration or live in rural areas seasonally. However, the influx of new residents has a great impact on rural areas, since city people have rich social capital and other resources to transform rural areas. Using the example of Verkhovazhsky district, where field studies have been conducted for several years, it is shown how city dwellers are involved in various types of rural economic and social life or offer new types of activities. Villages along the Vaga River valley host a base for restorers of wooden architecture, a center for wood-burning ceramic products, a museum of ancient horse harness and other objects created by city dwellers. At the same time, former city people also work at ordinary objects of rural social infrastructure, such as schools, cultural centers, shops, rural administrations, offering practices accepted in the cities, e.g. public lectures, book-crossing, separate garbage collection, rural second-hand, to rural residents.

The modern territorial organization of citrus cultivation in the Lankaran and Astara administrative regions, which are part of the Lankaran-Astara economic and geographical region, was studied using statistical materials, observations and questionnaires; tables and diagrams were compiled. Based on world experience, the natural and economic factors influencing the development of citrus fruits in the administrative regions are analyzed and protection measures are determined. The main goals and objectives were achieved by analyzing the historical development of traditions, the current state and prospects for growing citrus fruits in the study area. The cultivation of citrus fruits is one of the most demanded areas for the development of the agricultural sector of the Republic of Azerbaijan, which is not adequately studied from the economic and geographical point of view.
It was found that the process of planting and the location of citrus trees in the study area result in different yields of the same fruit variety. It is concluded that the yield of orchards is higher at farms located at 10‒30 m above sea level, with the correct location (recommended tree planting sites are on the southeastern, eastern and southern slopes of the mountains) and compliance with the planting distance (at least 3×3 m between trees) and agrotechnical standards.
The effective territorial organization of citrus cultivation in the Lankaran-Astara economic-geographical region and the identification of problems in the field are of great scientific relevance.

The evolution of a key area of the Kuban River Delta was studied. The core of the borehole KE-21 (18 m in depth) from the southwestern part of the Kuban River Delta (Kazachi Yerik-Perevoloka section) was studied by the complex of methods (lithological and malacological analysis, radiocarbon dating). The KE-21 section contains the Vityazevian-Dzhemetian (>5,0 ka BP) and Nymphean-recent (1,2–0,0 thousand years ago) sediment sequences of alternating lacustrine-lagoonal (dark-colored loams and clays) and alluvial sediments (light sands and sandy clays). The sequences are divided by a period of terrestrial evolution of the area under study during 5,0–1,2 ka BP. The brackish-water lagoons contained mollusk shells from 5 species, such as Cerastoderma glaucum (majority), Mytilus galloprovincialis and Bittium reticulatum (few), Donax trunculus and Tritia reticulata (single). There are no significant differences between each laminae in mollusk shell composition and percentage. The contemporary position of the layers does not reflect the synchronous levels of the Sea of Azov and the Akhtaniz estuary, principally due to local tectonic subsidence and clay shrinkage. The average sedimentation rate over the last 1,2 ka is about 5 mm/year, the max sedimentation rate is 19 mm/year (1860–1911).

An analytical phytoecological map of plant communities with various probable participation of a rare relict species Caragana jubata (Pall.) Poir. in the southern Baikal region has been compiled at scale 1:550 000. The original field material was taken as a basis, i. e. the locations with known projective cover (%) of C. jubata within biocenoses. The map is the result of a regression model. It was compiled using the data of Shuttle radar topography mission (SRTM) and Landsat-8 summer images (NASA, USGS) covering the study area. The map legend is based on the genetic-geographical classification of vegetation used in the legend of the map “Vegetation of the south of Eastern Siberia”. The map revealed possible distribution of communities with different participation of C. jubata in the southern Baikal region which depends on the ecological conditions of mountain slopes within different altitudinal belts. Suitable habitats for C. jubata are steep (up to 25–30°) rocky slopes in the mountain-taiga and high-mountain belts. The species forms its own communities in the subalpine belt; Dasiphora tenuifolia, Betula fruticosa, Carex pediformis are the most typically plants growing with C. jubata. The highest concentration of rare communities with C. jubata is within high mountains (1800–2000 m above sea level), thus proving the mountainous nature of the relic species. The projective cover of the species in the composition of plant communities decreases while the absolute heights become lower. The map was conveyed to the Tunkinsky National Park and could be a basis for diverse research in the field of conservation of rare plant species and rare plant communities in the region.