The idea of this special issue of the academic peerreviewed journal “Izvestiya Rosiiskoi Akademii Nauk. Seriya Geograficheskaya” devoted to the problems of land degradation and sustainable land management followed results of the International conference “Land Degradation and Desertification: Problems of Sustainable Land Management and Adaptation”, which was held at the Institute of Geography of the Russian Academy of Sciences in two stages (November 2020 and March 2021). Proceedings of the conference (available on: https://www.elibrary.ru/item.asp?id=44463100) were reviewed and selected by the organizing committee of the conference and recommended for publication by the extended meeting of the expert council of the Center for Combating Desertification and Drought named after N.F. Glazovsky

Actions to assess and combat desertification at the international level are currently associated primarily with the implementation of the modern concept of land degradation neutrality (LDN) in the framework of achieving Target 15.3 of the UN Sustainable Development Goals (SDGs). It was found that in the current Russian system of statistical land registration, there are no indicators for monitoring land degradation, except agricultural lands, which could correspond to the LDN indicators. The paper shows the possibilities of integrating land quality indicators and indexes used in Russia into the global land assessment system. It is proposed to streamline the data of various departments through a common agreed consistent system based on LDN indicators, for which a set of requirements is proposed. A conceptual diagram of the formation and a hierarchical structure for a system of land degradation indicators in Russia is proposed, including, on the one hand, dynamic indicators characterizing the LDN achievement, and on the other hand, indicators of the land state characterizing the quality of lands (in terms of risks and results of degradation) in relation to their target objectives use within the respective categories. Based on these approaches, preliminary analysis and selection of indicators from various departmental systems were carried out for integration into the global assessment system based on the LDN methodology. Further ways of integrating national and international systems for assessing land degradation are presented as follows: (a) development of a universal federal list of indicators and indicators for lands of various usage (categories and types); (b) the use of universal qualitative scales of indicators when varying the quantitative values of their indexes (by region, industry, land category, etc.); (c) the use of comparative scales of land quality in relation to both the best (maximization of indicators) and/or worst (minimization of indicators) objects in a given area/region.

Among the Russian federal subjects located in the steppe zone, Orenburg Oblast is a typical steppe region with developed grain production. The traditional soil-intensive technologies practiced here for a long time and focused mainly on the mobilization of natural soil fertility have led to widespread steppe lands’ degradation, territory desiccation, a decrease in the productivity of agrocenoses, and a critical reduction of landscape and biological diversity. The purpose of the study was the analysis of modern challenges to sustainable steppe land use, identification of historical, technological, and climatic preconditions for reducing the lands’ quality and agricultural productivity (using the case of Orenburg Oblast), development and scientifically substantiating of methods of steppe land-use adaptation to modern soil and climate changes. Electronic free access data about climate resources and economic activity results, as well as expedition materials, were used. The analysis of the field cultivation effectiveness, the climatic trends identification, and the determination of their relationship were carried out in accordance with natural and agricultural zoning and lands’ agroecological grouping. The stable soil-intensive orientation of the current agricultural lands’ structure has been confirmed, as before. The extremely unfavorable dynamics of hydrothermal conditions has an expressed arid trend in the Trans-Volga and Kazakhstan areas of the steppe and dry-steppe zones of the region. It is accompanied by a decrease in the productivity of artificial and natural cenoses’ phytomass. There is a direct relationship between the productivity of field crops (spring wheat) with the amount of precipitation and the Selyaninov’s HTC during the growing season. Also, there is an inverse relationship with the sum of active temperatures. The legal, land management and technological problems of the land structure optimizing, obstructing the official change of land status, are systematized. The introduction of an adaptive strategic approach is proposed. The scientific theories optimizing steppe land use through adaptive landscape farming systems are analyzed, the probability of their implementation in current conditions is estimated. The use of nature-like agricultural technologies that contribute to more efficient natural resources’ use and sparing anthropogenic impact on adjacent landscapes is justified.

Our research concentrates on the stability assessment of geosystems (including agroecosystems) in Rostov oblast. The southeast area of the region is considered the most vulnerable and was selected to conduct calculations on the degradation processes in comparison with the average indicators for the region. We provide a comparative assessment of aridity in the spatio-temporal aspect, including values for the moisture deficit, one of the main indicators of aridity in general. The aridity index, determined using various calculation methods based on data from representative meteorological stations, has shown that the degree of aridity increased in all areas of the region, which indicates a general trend towards an increase in climate aridity. Based on archived and current satellite images we calculated the vegetation index NDVI, and subsequently evaluated changes in the state of natural vegetation cover of Rostov oblast: sparse vegetation is predominant for the southern, southeastern, and northern parts of the region, and a tendency towards a decrease in areas with dense vegetation is noted. In the western and central parts of the region, there is a tendency towards a gradual increase in the area of dense vegetation. In the soils of agricultural landscapes, according to the results of a continuous agrochemical survey, it was found that from 1960 to 2000 there was a gradual decrease in the humus content, the rate of decrease over 40 years was 1.2–1.3. Since the 2000s, the humus content in the arable layer has been in a certain equilibrium, characteristic of the bioclimatic and production conditions of Rostov oblast, in the absence of erosion processes, a decrease in the humus content is not observed. Furthermore, we were able to assess the state of forest shelter belts using the same satellite images, and with the additional help of archival soil surveys from the Southern Research Institute of State Land Design. We consider a decrease of forest shelter belts to be one of the contributing indicators to the climate change process. Therefore, we suggest using this indicator for assessing various desertification processes.

The article reflects the long-term experience of scientific research in determining the role and influence of biophysical, socioeconomic, and territorial-organizational factors on the manifestation of land degradation processes (including soils) and their ecological and economic consequences in the Republic of Belarus. A scientifically grounded system of national criteria and indicators of land degradation, harmonized with the strategic goals of the implementation of the UN Convention to Combat Desertification (UNCCD), has been proposed. The developed scientific and methodological base is described in detail, used in identifying, mapping, assessing the state and monitoring of lands (soils) expose to water and wind erosion, accelerated transformation of organogenic (peat) soils, radiation-contaminated agricultural lands, lands disturbed by the extraction of peat and sand-gravel mixtures, expansion of transport infrastructure. Examples of practical constructive use of the results of land degradation assessment in the preparation of the Strategy and the National Action Plan aimed at its prevention, achievement of a neutral (zero) balance of land degradation and their restoration, substantiation and implementation of innovative agricultural technologies, improvement of territorial planning measures, mitigation of the effects of climate change are given. A system of measures is proposed to improve the regulatory, institutional, and scientific-methodological support for the successful solution of the problem related to the prevention and control of land/soil degradation in the republic.

The article considers the change of three main factors of spatial transformation of agriculture: natural, institutional-economic, and social. It shows how the results of agriculture historically changed depending on fluctuations in natural conditions, including periodic droughts. To identify relatively prosperous and crisis periods the change in moisture in the 20th and 21st centuries and the indicator of grain production were used. Examples of the catastrophic impact of droughts and adaptation to them in certain regions are given. Any crisis, including natural, highlights the chronic socioeconomic problems of the economy organization. The socioeconomic differentiation of rural areas, associated with remoteness from cities and transport highways, significantly affects the provision of agricultural production with labor resources. The latter depends on the duration and scale of rural depopulation and modern migration processes, which in some areas lead to social desertification, which is also disastrous for agriculture. Although the post-Soviet institutional transformations operated throughout the country, they had different consequences in the areas with different natural conditions, including in areas of waterlogging and natural desertification. An important factor in the spatial differentiation of agricultural results is the combination of organizational forms of management in different regions: from agricultural holdings to personal subsidiary farms. The result was a change in the specialization of production in a number of regions, an increase in its organizational and spatial polarization and concentration, although it led to an overall increase in the volume of agricultural production in the country. The main consequence of the transformation processes of post-Soviet Russia was the compression of agricultural land use and the shift of grain production to the southern regions. This made it more sensitive to climatic and weather fluctuations, despite the modernization of production.

The features of the transformation of individual components of the natural environment in the south of Eastern Siberia (Republic of Buryatia was analyzed in detail) under the conditions of climate change, which have a critical impact on the ecosystem services of forest lands, have been determined. A system of sequential and complementary methods has been applied, which allows an objective analysis of this impact and its assessment: remote sensing methods, correlation analysis, cartographic method, methods of the concept of total economic value, and “ecosystem-based adaptation.” The air temperature, precipitation, and NDVI trends were calculated for the wet (1982–1999) and dry (2000–2018) periods. Temperature rise, as the most critical parameter of the state of forest lands, is observed for the entire study area; at the same time, zones with low growth rates of surface temperature are interspersed with zones with high growth rates, both in latitudinal and longitudinal directions. The wet period is characterized by positive trends in the amount of precipitation for almost the entire study area. During the dry period, negative dynamics of the amount of precipitation is observed for the predominant part of this territory. The wet season is marked by an almost universal rise in NDVI. During the dry season, forest vegetation is characterized by multidirectional trends in NDVI and precipitation; here the NDVI dynamics is influenced by temperature. These patterns also predetermine changes in the development of ecosystem services of forest lands in the area under consideration. It has been determined that climate change has a negative impact on the predominant part of the ecosystem services of forest lands. The greatest negative impact on these services over a long period of observation (1936–2015) was caused by forest fires, which by the end of this period had significantly increased both in number and in area. A set of measures is considered to facilitate adaptation of forest land management to climate change.

The relationship of changes in annual moisture with spring-summer and summer moisture in twelve federal subjects in the south of European Russia in 1901–2018 was analyzed using the Standardized-Precipitation Evapotranspiration Index (SPEI). The revealed close relationship between the annual SPEI and the aridity index justifies the usage of the SPEI to assess changes in annual moisture conditions. It was found that changes in moisture in May–July were associated with fluctuations in annual moisture more significantly than those in summer moisture. Changes in the seasonal moisture in the Volga, Trans-Volga and Northwestern Caspian regions explained 50–65% of the variability of annual moisture, while the contribution of the seasonal moisture varied from 30 to 60% in other federal subjects of the south of European Russia. The comparison of the aridization phases identified in each federal subject and their systematization by the duration showed that the change in the frequency of spring-summer and summer droughts affects the formation of alternating multi-decadal periods of increasing/decreasing climate aridization in the study area. Two-four dry periods and two-three wet periods are typical for most of the considered federal subjects. It was revealed that drier conditions of the spring-summer and summer periods were observed at the beginning and middle of the 20th century in the south of European Russia. The increasing seasonal moisture in the second half of the 20^th century was replaced by a drier phase at the beginning of the 21st century. It was shown that droughts during dry periods are a reliable indicator of a dry year: spring-summer droughts in Stavropol krai and summer droughts in Volgograd oblast and Krasnodar krai.

Multiscale relict lakes are the essential elements of the steppe plains in Altai krai in Russia (South Siberia). Based on the remote sensing data (Landsat and Sentinel-2 images), we analyzed the water bodies’ area dynamics in the two endorheic lake systems of the Kulunda Steppe–Kulunda and Plotava. We found no evident tendency to reduce water bodies’ area between 1989 and 2020. Despite several severe droughts during the last 30 years, water bodies of Kulunda and Plotava lake systems have not experienced any extremely sharp reductions. The SPEI index was used to estimate the duration and intensity of droughts. It was shown that the interannual dynamics of lakes weakly depend on weather fluctuations of a particular year. Statistically significant correlations were found only with 24- and 36-month SPEI indices, which generally indicated the relative stability of feeding mechanisms of lake systems in Kulunda Steppe. Despite the significant difference in catchments and lake areas, the Kulunda and Plotava lake systems were characterized by high synchrony of interannual fluctuations. The relative range of intra-annual variation within the small Plotava lake system was significantly higher than in the much larger Kulunda system. Stability in the functioning of the Kulunda lake systems may be related to a very moderate human impact on the feeding watercourses in recent decades. There was the absence of large-scale water withdrawal and flow regulation.

The article presents the results of geoinformation mapping and analysis of wildfires in natural landscapes of Astrakhan and Volgograd oblasts and the Republic of Kalmykia for 1997–2020. On the basis of expert interpretation of Landsat satellite images with verification based on the detection data of active combustion and burnt-out areas, more than 13.5 thousand burns with a total area of over 150 thousand km2 were identified. The largest burned-out area was recorded in 2006—more than 18 thousand km2. In total, 62.5 thousand km2 were covered by fire in these regions, which is one-third of the natural zonal landscapes. Up to 90% of the number of fires is represented by incidents with an area of up to 10 km2, while half of the burnt area is provided by catastrophic fires with an area of more than 250 km2 each, which occur 2-3 times a year. The maximum frequency of fires was 14 cases during the study period. Analysis of the proximity of burned areas showed the presence of spatial patterns in their distribution. The sites with the highest frequency of fires are located in the Volgograd and Astrakhan Trans-Volga region with less agricultural development, as well as in the Chernye Zemli Nature Reserve and its environs, where livestock grazing is prohibited. The growth of livestock in Kalmykia and the right-bank part of the Astrakhan oblast, the involvement of deposits in circulation in Volgograd oblast in the last decade resulted in a decrease in the number and area of fires. In Volgograd oblast, a significant negative trend in the number of fires was noted, and in Kalmykia–in both the number and area. The obtained results, in addition to data on the dynamics of burnt areas, represent the possibility of determining the duration of pyrogenic successions, which will make it possible to study the patterns of changes in the state of landscapes after fires in different years, taking into account their frequency. Also, the results will help optimize fire prevention.

The need to automate and simplify the spatial and temporal monitoring of economically important soil characteristics, in particular the carbon content of intensively used lands, dictates the continued search for relatively simple ways of their remote evaluation. We discovered medium-strength significant relations of LS-factor (Slope Length and Steepness factor; erosion potential of the relief), and soil characteristics as a result of a statistical analysis of field observations, laboratory experiments, and digital elevation models obtained from space remote sensing data. Surface data were obtained from model transects located in different relief positions of long-term arable chernozems (Kursk Oblast, Russia). These relationships are expressed in decreased content of the key nutrients and compounds (SOC, nitrogen, and water), as well as in reduced presence and altered activity of soil microbiota. We assume that the main reason for this is water erosion and less water availability on steeper slopes. Based on our results, we believe that LS-factor calculated on the basis of satellite remote sensing data is applicable for evaluation of erosion hazard, as well as for prediction of carbon content and other related significant physical, chemical, and biological indicators of the state of perennial arable haplic chernozems for a large spatial scale. At the same time, we found that the spectral characteristics of the soil surface obtained from remote sensing data are less applicable for these purposes. This is due to the dependence of the obtained satellite data on the survey conditions (weather, soil tillage techniques, vegetation cover characteristics) and the limitations imposed by the insufficient resolution of the available satellite images.