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 Arid EcosystemsJournal Prestige (SJR): 0.2 Number of Followers: 2      Hybrid journal (It can contain Open Access articles) ISSN (Print) 2079-0961 - ISSN (Online) 2079-0988 Published by Springer-Verlag  [2469 journals]
• Heavy Metals in the Soils of Steppe Ecosystems in Western Transbaikalia

Abstract: The results of an experimental study of the transformational flow of heavy metals (copper, zinc, nickel, and lead) from soil-forming rocks into chestnut soils and then into virgin herbage and humic substances are presented. The soil-forming rocks include deluvial and deluvial–proluvial sediments, as well as sand and pebble sediments; their weathering, displacement, and redeposition lead to unequal granulometric, mineralogical, and chemical rock compositions, thereby influencing the composition of the soil cover. Chestnut soils are characterized by an arid climate, a long-term frozen state, low bioproductivity, low thickness, a light granulometric composition, and low humus content. Humic substances were extracted with the Grimme method. The concentrations of microelements were determined via atomic absorption with direct electrothermal atomization of samples. Heavy metals were determined on an atomic absorption spectrophotometer (AAS-15 Perkin Elmer). It has been revealed that the amount of copper and nickel is low in the soils due to the depletion of rocks in these metals, while the content of zinc and lead is higher, which is reflected in the state of vegetation and humus.
PubDate: 2022-06-01

• Integrated Approach for Assessment and Monitoring of Forests Conditions in
the Drylands of Sudan

Abstract: Forest resources in the drylands of Sudan are fluctuating in their tree cover and eco-functions. Reliable and timely information on their status is pivotal to address their socioeconomic and environmental benefits in the national environmental policy. Thus, this study aimed to develop an assessment and monitoring systems for their trees’ cover, threats, and disturbances along with forests dependents’ needs and activities in Wad Al-Bashir forest area with a view of establishing database for robust forests management plans and strategies. The study combines Ground-Based Survey (GBS), socioeconomic survey (structured questionnaire and key Informant interviews) and geo-special technique (satellite images for 1988, 2008 and 2018) as integrated methods for assessing and mapping the past and current forest conditions and disturbances. GBS results found and georeferenced sites of biotic and abiotic forest disturbances as well as man’s detrimental activities like trees logging which have had affected trees’ health and contributed to its degradation. The biotic threats were: invasive species (Acacia nubica), pest (Sinoxylon senegalensis) and climbers, while the effect of abiotic was mild like the wind effects. Social survey findings on the other hand, signposted the direct and indirect causes of deforestation and forest degradation. Direct causes were the conversion of forestland onto farmlands, illegal cutting and uncontrolled-grazing consecutively. Indirect causes were improper forest policy implementation, population growth, poverty and land tenure system. The geospatial technique showed considerable land use/land cover changes, where 2008 had considerable forest cover (72.2%) compared with 1988 (63.8%) and 2018 (58%), and accordingly, 2018, encompasses vast farmland area than 1988 and 2008 accounting for 38, 25.9, and 6.1% respectively. The study concluded that the effectiveness of using GBS, socioeconomic survey and geospatial technique as incorporated methods that could give a representation of all forests’ related aspects in one scene as well as better understanding for the genuine status.
PubDate: 2022-06-01

• Slope Exposure and Its Effect on Chemical and Biological Soil Properties
on Agricultural Terraces of the Eastern Caucasus

Abstract: This paper discusses the relationship between the slope exposure and chemical and microbiological soil properties on agricultural terraces. Terraces formed on limestone and shale rocks in the medium-altitude zone of the eastern Caucasus were studied. It is established that the slope exposure significantly affects the properties of soils formed on similar parent rocks. The formation of terraces with nearly horizontal arable surfaces changes the sunlight angle of incidence, thus increasing the heat supply to soils on north-facing slopes and reducing the heat supply to soils on south-facing slopes. Such changes in the thermal regime in the upper horizon of terrace soils reduce the differences in chemical and microbiological properties between soils on north- and south-facing slopes as compared to the background soils. On gentle (5°–15°) slopes with the greatest terrace width, the leveling effect of terracing is more strongly expressed in comparison with soils of narrow terraces formed on steep slopes.
PubDate: 2022-06-01

• Soil Isotopic Signatures in the Diagnostics of Aridization Processes in
Landscapes of the Republic of Dagestan

Abstract: The planetary climate system is currently unstable, and its challenges manifest themselves primarily in ‘marginal’ parts of the biosphere, including mountain landscapes. Mountain ecosystems in arid regions are especially susceptible to natural or anthropogenic external impacts, and their recovery after disturbances takes the longest amount of time. The purpose of this study was to examine the natural and specific features of impacts exerted by climatic and anthropogenic factors alternating with each other or acting cumulatively throughout the Holocene on the ecosystems of Inner Dagestan with the stable isotope technique and to assess their contributions to the modern progressive aridization of landscapes in the eastern Caucasus. The soil cover in vertical zones (2000–4000 m a.s.l. (Baltic Elevation System)) of the eastern Caucasus was studied in the Akhtyn district, Inner Dagestan, in areas affected by different types of economic activity (pastures of varying grazing intensity, hayfields, and natural meadows). The following soil parameters were determined: general chemical properties (actual acidity and carbon and nitrogen content), magnetic susceptibility, humus state of the soils, isotopic composition of carbon (δ13C) and nitrogen (δ15N) (via mass spectrometry), and soil age (via humus radiocarbon dating). It is established that the conditions of dynamic soil formation result in the appearance of a polygenetic soil cover: the epochs of surface stabilization correspond to buried horizons and soils, while epochs of exogenesis activation correspond to layers with an elevated rubble content and rocky horizons. Like exposed and buried horizons, buried soils of different ages have contrasting properties. This indicates that different epochs of buried soil formation featured different climatic conditions: arid epochs of the early Boreal and Atlantic optima of the Holocene cyclically alternated with colder and more humid ones, while the medieval optimum featured a temperate climate similar to the modern one. The Little Ice Age was not clearly pronounced in Inner Dagestan. However, the identified climate humidification trend is negated by the ‘steppification’ of landscapes as a result of their anthropogenic use.
PubDate: 2022-06-01

• Technopedogenesis and Its Effect on Morphological and Chemical Soil
Properties in Recreational Areas. The Case of Sasha Filippov Public Garden

Abstract: This paper discusses soils in green recreational areas of Volgograd urban landscapes on the example of Sasha Filippov Public Garden. The soil cover in the public garden is represented by typical (Urbic Technosol), replanted (Urbic Technosol (Mollic)), and technogenic (Urbic Technosols (Hyperartefactic)) urbostratozems, replantozems (Phaeozem (Prototechnic)), and urbostratozems on buried chestnut soils. Sealed urbostratozems (Ekranic Technosols) occur under buildings and road surfaces. The presence of buried horizons indicates that the initial soil cover in this area was represented by chestnut soils (Haplic Kastanozems (Loamic)). The average thickness of urbic horizons (UR) is 95 cm; the average thickness of recultivating layers (RAT) is 50 cm. The soils of the public garden are diverse in terms of their chemical and physical properties. The soil carbon content in the urbic and recultivating horizons varies from 0.11 to 2.46%. Chemical analysis of the urbic and filling horizons showed that the content of readily soluble salts and carbonates is low (0.11 and 1%, respectively). In the RAT layers and anthropogenic UR horizons, the average density values vary in the range of 1.43–1.46 g/cm3. The average densities of buried horizons are as follows: 1.58 g/cm3 for BMK, 1.62 g/cm3 for B, and 1.53 g/cm3 for BCA, which is higher than the average density of native chestnut soils. The average density of the calcareous parent rock (Cca) is 1.38 g/cm3. The results provide insight into the soil genesis in urban recreational areas in connection with the anthropogenic transformation of natural chestnut soils in the dry-steppe natural zone.
PubDate: 2022-06-01

• Factors of Territorial Differentiation of the Agricultural Landscape and
Prospects for the Preservation of Steppes in Belgorod Oblast

Abstract: The rational organization of territories with agricultural landscapes, with consideration of the optimal spatial distribution of areas, which reduce agrogenic carbon emission, may favor a smaller carbon footprint of farming at the district level. The transition to carbon-neutral agriculture and the optimization of the agricultural landscape structure are especially urgent for such regions as Belgorod oblast, which provides 4.8% of the total value of farm products in Russia and where there are virgin areas of steppes that effectively regulate the carbon balance. Trends in the dynamics of farm lands in the structure of contemporary agricultural landscapes were revealed and compared to changes in the areas of preserved virgin steppes and lands of the nature reserve fund from an analysis of statistical parameters, cartographic and published data, reports from relevant departments and ministries, and materials of long-term terrain and experimental studies performed by the authors in Belgorod oblast at the intradistrict level in the period from 1990 to 2020. Agro-resource areas, including municipal districts with similar trends of change in areas of farm lands in the structure of agricultural landscapes, with the same farm specialization, and with identical changes in the natural, social, economic, and environmental situation have been identified: (1) an agro-resource area of industrial concentration near large cities in the western and central parts of the region; (2) an agro-resource area of conflicts between agricultural and industrial environmental management in the northern part of the region; (3) an agro-resource area of the southeastern agricultural and industrial part of the region. The key factors determining the potential of farm production and the trends in the dynamics of areas of agricultural landscapes have been identified within these areas. The percentage of specially protected natural areas that are significant for the reduction of agrogenic carbon emission is estimated, and their importance for the maintenance of carbon neutrality in modern economic development is indicated. The areas of agricultural landscapes within the specified agro-resource areas decrease to a smaller rate from the west to the northeast and southeast, but their agricultural–natural potential drops. This is explained by the enhanced effect of negative environmental factors, the insufficient introduction of an adaptive land-use system, the disproportion of investments in the agro-industrial complex, and the smaller number of working people employed in agriculture. It is shown that the conflicts between agricultural and industrial environmental management increase toward the east and northeast. The relationships between the key factors affecting agricultural use of landscapes and the dynamics of the areas of agricultural landscapes within the specified agro-resource areas are determined with the methods of mathematical statistics. The prospects of territorial protection of virgin steppe areas for solution of problems of carbon-neutral agriculture under the conditions of the revealed trends in the dynamics of areas of agricultural landscapes are analyzed. The revealed features of the transformation of the agricultural landscape of Belgorod oblast will enable the optimization of its structure to create a carbon-neutral agriculture and to increase the efficiency of the regional network of specially protected natural areas.
PubDate: 2022-06-01

• Water Potential of the Republic of Kyrgyzstan: Problems and Potentials of
Economic Development

Abstract: Irrigation remains an essential component of food security in many parts of the world. Kyrgyzstan is included in this number, but, at the same time, the water resources of Kyrgyzstan are still not used efficiently enough. This study gives an assessment of the conditions for the formation and quality of water resources in the Kyrgyz Republic based on an analysis of the new draft State Program for the Development of Irrigation of the Kyrgyz Republic for 2017–2026 and an assessment of the irrigation facilities of the Republic that takes into account their relevance and economic and technical indicators. The modern realities demonstrate the need for a careful and rational use of natural resources. High-quality, safe water is becoming one of the most in-demand resources in many countries of the world, therefore, “water powers” can make water their strategic resource, but the operation and maintenance of water-management systems requires significant financial investments. Payment for water use can become the basis for reform of the economic mechanism of interstate relations. The study resulted in the formulation of reasonable directions for the strategic nature of the modernization of the reclamation fund and the expansion of the volume of ongoing reclamation activities related to high-priority measures for the development of the rational use of the water balance.
PubDate: 2022-06-01

• Hydroecological Consequences of Climate Changes in the Water Regime of the
Spring Flood in the Upstream of the Arpa River

Abstract: The paper considers long-term trends in changes in river flow of spring floods, hydroecological and hydroeconomic consequences of climate change in the upstream of the Arpa River. The study uses data on average daily water consumption and water temperature in the Jermuk River section of the Arpa River, and data on the main meteorological elements at the Jermuk weather station located in the upstream flow of the Arpa River basin. It is presented that maximum water flow during the passage of the spring flood is one of the most important characteristics of the flood. The absolute maximum flows vary from 8.26 to 199 m3/s, and average maximum flows from 1.86 to 116 m3/s. The interannual changes of the dates of the beginning, termination, duration and volume of spring flood runoff, as well as temperatures of the surface air layer and precipitations in December–February and April–June, maximum water reserve in snow, and water temperature in April–June are have been considered and evaluated. It is shown that over the past 28 years, the volume of floods and their duration is being reduced, the terms are shifted towards earlier dates, and maximum water discharges during the flood period are reduced. It was also established that winter and spring–summer (in April–June) average air temperatures, precipitation in the winter period is increased, and maximum water reserve in snow becomes less. As a consequence of modern changes in the hydrological regime of the spring flood, multiple hydroecological and hydroeconomic problems are manifested that require increased attention and consideration. With interannual fluctuations, a change in the flow volume of the spring flood in the early to mid-1990s is clearly visible, after what a period of their significant and steady decrease started. The rate of change in flood volumes in the second period (1993–2020) was –17.9 million m3/10 years and –13.2 million m3/10 years. In the first period (1957–1992) there was an increase in flood runoff, the rate of change thereof was +9.63 million m3/10 years and +4.07 million m3/10 years, respectively. Over the past two–three decades, the volume of spring flood runoff has decreased by almost 50.1 million m3, while the runoff in April–June has decreased by almost 37.0 million m3. This trend is due to an increase in winter air temperatures and increase in the number and duration of thaws, which leads to a decrease in pre-spring water reserves. It is noted that in the upstream of the Arpa River basin, current climate changes are leading to significant degradation of the flood as a phase of the water regime: increase of the surface air temperature in the winter season is the main reason for the decrease in water content in the spring in the upstream of the Arpa River. Correlations were obtained between the values of the volumes of the spring flood in the upstream of the Arpa River, calculated from April to June and from the beginning of the flood to its end. This relationship can be used to estimate, calculate, and check the volume of spring floods, given the volume of runoff in April–June.
PubDate: 2022-06-01

• Salinization of Soils in the Don Valley under Conditions of Terminated
Irrigation

Abstract: This article presents a study for the identification of the current salt state of the soils of the General Irrigation System built near the Tsimlyansk reservoir in 1959 in the dry-steppe zone of Volgograd oblast in the Don Valley. The system is currently in a 30-year irrigation shutdown period. In the interpolation study, soil-salinity maps that cover different soil depths were constructed. They are based on field surveys and water-extract data (1 : 5) from soil samples taken in 2020. Water-extract data obtained at the Volgograd Hydrogeological and Land Reclamation Expedition in 2018 were also used. The key area of study was located on the second floodplain left-bank terrace of the Don River and included a territory in which a high groundwater level (1.5–3 m) with strong mineralization (3–10 g/L) formed by the beginning of the 1990s during a long period of irrigation. This led to the formation of a meadow solonchak and secondary saline soils with a high degree of salinity, which prompted us to map the salinity of soils in this area and to determine the changes over the past period. Analysis of the soil-salinity maps made it possible to assess the current salt state of soils located on various relief elements of the second terrace of the Don River and to compare the current salt state of soils with the period of the late 1980s–early 1990s, which showed a gradual desalinization of previously saline areas and the development of alkalization of the upper soil horizons. The desalinization was caused by the cessation of irrigation, and alkalization was caused by the location of the general system in the solonetz zone, the long period of irrigation from 1960 to 1992, and irrigation from the Tsimlyansk reservoir with water with a high sodium concentration. Salinity maps showing the depth of the salt horizon provide information necessary for the development and selection of optimal reclamation measures to restore the soil fertility. Preliminary recommendations for the solution of this problem upon the resumption of can include quality control of the irrigation water, the use of periodic (once every several years) water-charging spring washing of the 0- to 70-cm layer to push accumulated salts out of the aeration zone, gypsum to ensure the displacement of exchangeable sodium, suppression of the alkalinity and the removal of water-soluble sodium to the underlying horizons beyond the root layer, the use of drip irrigation, and an increase in the share of perennial legumes and cereals in the structure of sown areas. The article also shows that the spectral indices given in the literature cannot be used to determine the soil salinity from space information in relation to the selected study area. This was confirmed with multiple regression analysis, in which the values of the spectral indices in four image channels from the Sentinel-2 satellite and the salinity values of different soil horizons at the sampling points obtained as a result of field and laboratory work were used as features. According to the results of regression analysis, no significant relationship between the spectral indices and salinity values was revealed in any soil horizon. The resulting correlation coefficients were less than 0.5, and, hence, the relationship was very low.
PubDate: 2022-06-01

• Variability of Isotope Composition (15N/14N and 13С/12С) in Tissues and
Organs of Mediterranean Soil Invertebrates

Abstract: In recent decades, various isotopic methods have been widely used to study trophic relationships in soil ecosystems, because the isotopic signature of heterotrophic organisms reflects the isotopic composition of their preferred food objects. The composition of carbon (δ13C) and nitrogen (δ15N) isotopes of biological objects is most often used in such environmental research. However, the correct use of the method to reconstruct detrital food webs is often hampered by the individual (within the body) variability of the carbon and nitrogen isotopic composition in the tissues and organs of many groups of soil invertebrates. The goal of this study is to compare the individual variability of isotopic composition of various tissues and organs of common Mediterranean species of woodlice (Armadillo officinalis, Armadillidae, Isopoda and Armadillidium vulgare, Armadillidiidae, Isopoda) and the Mediterranean banded centipede (Chilopoda, Scolopendromorpha, Scolopendra cingulata). Soil invertebrates were collected on the territory of the Utrish State Natural Reserve (Krasnodar krai, Russia). Isotopic analyses were performed for the exoskeleton, muscles, intestinal walls, fat body (only for centipedes), reproductive system, legs, and a whole, homogenized body. The isotope composition of δ13С and δ15N was estimated with a set of equipment consisting of an elemental analyzer and an isotope mass spectrometer. The differences in δ13C between the tissues of woodlice reached 5–6‰ due to the incorporation of inorganic carbonates in the exoskeleton. The tissues of the banded centipede showed no significant difference in their isotopic composition. The trophic position of the large woodlouse species can be best characterized by the isotope analysis of muscle tissues. The use of limbs is possible only after preliminary assessment of the carbonate content in the integumentary tissues of the species. The homogenization of large species is unfavorable, as well as the remains of exoskeleton fragments and food debris in the analyzed sample. For centipedes, one can use not only muscles but also homogenized samples of the whole body, as well as individual parts of the body and organs, excluding the gut contents. The results are applicable for the optimization of soil-zoological studies via isotopic analysis of the tissues of various invertebrates.
PubDate: 2022-06-01

• Dynamics of Microbiological Diversity of Soils in the Chu Valley during
Land Use Change in Pastures

Abstract: Soil microflora is one of the first to feel a negative impact and can serve as a biological indicator of changes in the soil structure and the degree of impact on the soil ecosystem. In 2020, studies were carried out at two sites located in the Shamshy Gorge in the Chui region of the Kyrgyz Republic. One of the plots was withdrawn from pasture use for one year in 2020 and two years in 2019 as compared to the actively used control option. The microbiological diversity was studied with conventional methods of microbiology. The micromycetes of the studied soils were represented in the dominance of species resistant to adverse environmental factors, Trichoderma, Cladosporium, and Alternaria, i.e., the species diversity was insignificant, with a predominance of representatives of dominant species. A decrease in the anthropogenic load in the studied areas has led to the activation of microbiological processes and a significant increase in soil microbiodiversity, which is indicative of improvement in the enzymatic properties and an acceleration of the soil self-healing process. Studies have also shown that soils in the regime of unregulated overgrazing are significantly susceptible to drying and trampling, which leads to a decrease in microbiological diversity in the soil ecosystem and the dominance of microorganism forms that are resistant to adverse environmental factors. The obtained data suggest that overgrazing affects the structure of soil microbiocenosis, replacing it with more drought-resistant species. Thus, the microbiological diversity of soils subjected to varying degrees of anthropogenic pressure can serve as a biological indicator of the state of the soil ecosystem. It is also necessary to resolve the issue of the regulation of the rotational grazing of livestock, which can also ensure the preservation of pasture productivity and contribute to the conservation of the biological diversity of flora and fauna of pastures, respectively.
PubDate: 2022-06-01

• Projected Exploitable Groundwater Resources in the Dagestan Piedmonts

Abstract: The projected exploitable underground freshwater resources (PEUFR) on the territory of a hydrogeological structure of the third order, a small artesian basin system (SABS), was determined with allowance for the water shortage in the Dagestan piedmonts under the conditions of an acutely arid climatic regime. Geologically, the study area belongs to the Tertiary folding, where work has been carried out over the past decades to search for, explore, and evaluate reserves and predicted resources for the use of fresh groundwater for domestic and drinking water supply. The previous studies were generalized, and promising hydrogeological regions were identified with calculation of the predicted resources for the use of fresh groundwater, especially wide, deepened river valleys that turn into alluvial fans and form foothill plumes. The data on the meteorological, hydrogeological, and geological knowledge of the territory, the chemical composition of groundwater, and the lithology of the cover and aquifers have been processed; prospective sites for groundwater exploration and areas of their supply, transit, and discharge were identified to develop a design scheme. The work of existing water intakes on the approved reserves was analyzed, and the potential to increase the PEUFR outside the fields was considered. The hydrogeological conditions of the region and the SABS and a brief description of previously explored groundwater deposits are given; promising areas for groundwater exploration are identified, and their projected exploitable resources are calculated. The PEUFR for the limited synclinal structures of the Upper-Middle Sarmatian deposits was determined with the condition of precipitation infiltration. Its value was 25 600 m3/day for synclinal artesian intermountain basins and for Chokrak, Chokrak-Tarkhan, and Konk-Karagan sandy–argillaceous deposits.
PubDate: 2022-06-01

• Change in the Reserves of Active Elements and the Thermal Regime of
Natural and Anthropogenically Modified Soils of the Nazarovskaya Forest
Steppe

Abstract: The paper presents findings on the change in the content and reserves of water-soluble forms of calcium, magnesium, and organic and inorganic carbon and the moisture of natural and anthropogenically modified soils, as well as the temperature change in natural soils at different locations. The relevance of the study is driven by the need to analyze changes in the considered parameters under short-term climate changes in the isolated forest steppe of the Nazarovskaya Depression. The study involved generally adopted methods, e.g., landscape geochemical, comparative analytical, comparative geographical, and statistical methods. The maximum moisture reserves were found in meadow–wetland soil, and the minimal reserves were found in meadow–chernozem leached soil. The values were close for ordinary chernozem of the meadow subtype and its anthropogenic modification (fallow), which can be attributed to their location in the relief and hydrothermal regime. It was experimentally established that ordinary chernozem of the meadow subtype (in situ) features a temperature curve with a steeper slope, lower freeze temperatures, and a longer period with negative temperatures than meadow–wetland soil. New knowledge was obtained on the change in the reserves of water-soluble forms of calcium, magnesium, organic and inorganic carbon, moisture content, and fluctuations of climate parameters, e.g., air temperature and total precipitations. The study identified annual variations in the temperature of natural soils (in situ) of the isolated forest steppe for a more complete understanding of dynamics of the natural processes and for their use in further research on an isolated forest-steppe in a changing climate.
PubDate: 2022-06-01

• Influence of Climate Change on Soil Degradation in Arid Zones of the Volga
Region

Abstract: The goal of the research was to establish the impact of climate change on the processes of soil degradation and desertification in arid regions of the Volga region. The study material was the observational data for 1971–2020 on 20 meteorological stations, as well as the results of soil-ecological and hydrogeological monitoring at research stations of the Federal Center of Agriculture Research of the South-East Region in the prevailing soil and climatic zones on the territory of Saratov oblast (forest–steppe, steppe, dry steppe and semidesert). The signs accompanying aridization, desertification, and land degradation were revealed and differentiated by natural zones. In particular, the average annual air temperature increased in comparison with the climatic norm by 1.0–1.2°C, and the greatest increase (by 2.0–2.2°C) was observed in August. The average temperature of the soil surface during the warm period increased by 1.1–1.5°C. The risks of severe atmospheric droughts during the entire growing season increased throughout the entire territory, most notably in the semidesert zone (from 55 to 82%). The amount of precipitation increased by 10–25% in the spring and decreased by 23–30% in the summer. The boundaries of the semidesert zone have shifted to the north and northwest. The tendency of changes in the hydrological regime of zonal soils from nonleaching to periodically leaching in 20–40% of years is outlined. The values of the aridity indices of the territory calculated for the period from 2001 to 2020 increased in comparison with the climatic norm for 1971–2000 by 3–6%. This is an indicator of growing climate aridity during its current warming. As a result, high rates of dehumification (a decrease in the relative content of humus by 21–35%) and changes in the structural state of the arable layer and particle-size distribution (a decrease in water-resistant aggregates of >0.25 mm from 39% to 31.8% and the absolute content of physical clay by 7.5%). At the same time, there is an increase in the mineralization of groundwater from 2500 to 7000 mg/L, as well as an increase in the content of toxic salts in the soil solution. Thus, the content of Cl– ions $${\text{SO}}_{4}^{{2 - }}$$ in places of recharge by groundwater increased from 0.27 to 0.56 mg/eq and from 0.27 to 13.27 mg/eq respectively. The cation values also increased: Ca2+ increased from 0.30 to 4.41 mg/eq and Mg2+ increased from 0.12 to 5.59 mg/eq, The amount of K+ and Na+ rose from 0.09 to 0.28 mg/eq The development of processes of local salinization and waterlogging is noted in the lower relief elements.
PubDate: 2022-03-01
DOI: 10.1134/S2079096122010061

• Assessment of the Environmental Balance in Agricultural Landscapes of the
Dry Steppe Zone (Chestnut Soils, Volgograd Oblast)

Abstract: The agricultural landscapes of the dry steppe zone of chestnut soils (middle reaches of the Don River and lower reaches of the Volga River) exist in harsh soil–climatic conditions (the moisture deficit reaches 30–40%) and are currently affected by intense economic use. Many researchers believe that this is the reason behind their imbalance and varying degrees of degradation. Therefore, the procedure for agroecological monitoring and the system to assess the environmental balance in agricultural landscapes, including the methodology of its implementation, are of special scientific and practical importance to the formation of rational land-use schemes in zones of insufficient moisture supply. This study has resulted in new knowledge about processes occurring in agricultural landscapes of the dry steppe zone of chestnut soils affected by various cultivation techniques, agricultural technologies, and land-use methods. It is established that agrotechnological factors, including the sowing structure, crop-rotation scheme, basic tillage techniques, nutrient-alienation level, fertilization rates, protective complex of agrophytocoenoses, land use infrastructure, woodiness, and protection against systemic erosion, significantly affect the environmental balance in agricultural landscapes; these factors can either result in a high degree of environmental balance in the studied object or, conversely, cause its degradation. A scoring method has been developed and proposed for practical use to assess the environmental balance based on ten indicators for agricultural landscapes of the dry steppe zone of chestnut soils. The presented methodology evaluates agricultural landscapes with points on the following balance scale: 5 points (absolutely balanced), 4 points (balanced), 3 points (moderately balanced), 2 points (poorly balanced), and 1 point or less (not balanced). The developed set of criteria and methodology of environmental evaluation make it possible to assess the environmental balance in agricultural landscapes of the dry steppe zone of chestnut soils with a high degree of objectiveness. The assessment results can be used as the basis for organizational and technological decision-making and actions to restore the environmental balance in southern provinces of the Russian Federation and to standardize the anthropogenic pressure on the agrosphere in arid conditions.
PubDate: 2022-03-01
DOI: 10.1134/S2079096122010024

• Characteristics of the Seasonal Dynamic Structure of Phytocenoses on Sandy
Grounds in the South of European Russia

Abstract: The study provides insight into the species diversity, productivity, proportional participation, and seasonal variability of species in natural and artificially created phytocenoses on sandy grounds in the south of the European Russia. Particular attention is given to the role of the effects of moisture condition on the formation of the species diversity in various communities. The Tsymlyansk and massif was monitored with ecological geobotanical surveys. The herbaceous plant–shrub layer comprises 183 plant species from 41 families. The Simpson index suggests that the dominance of species from family Poaceae is the most pronounced in the area of excessive moisture (II). Species from the families Asteraceae, Fabaceae, and Poaceae are dominant in the area of sufficient and variable moisture (III), moderate moisture (IV), and the sites of insufficient complex moisture and the area of a severe lack of complex moisture under sandy hummocks and moderate in kolkas (birch and alder groves) and diffused sands (V). According to the Jaccard index, the similarity of the species composition is closest in terms of the species diversity between the areas of (Va) insufficient complex moisture and (Vb) a severe lack of complex moisture under sandy hummocks and moderate in kolkas (birch and alder groves) and diffused sands (90%); (IV) moderate moisture and (Vb) a severe lack of complex moisture under sandy hummocks and moderate in kolkas (birch and alder groves) and diffused sands (89%); (III) sufficient and variable moisture and (IV) moderate moisture (87%); (II) excessive moisture and (IV) moderate moisture (87%). In the area of moderate moisture (IV), most of the mass was comprised of the grasses Agropyron cristatum L., A. elongatum (Host) P. Beauv., Festuca valesiaca Gaudin, F. beckeri (Hack.) Trautv., and Poa pratensis L., while Artemisia campestris L. and Galium verum L were predominant among the forbs. On average, the grasses in the community accounted for 66.5%, and the forbs accounted for 33.5%. Similarly, in the area of sufficient and variable moisture (III), the phytomass was largely formed by species from the family Poaceae, such as, Elytrigia repens (L.) Nevski and Agropyron elongatum (Host) P. Beauv. Agropyron cristatum L. The phytomass was considerably influenced by Artemisia campestris L., Artemisia vulgaris L., and Artemisia arenaria DC. Shifting sands should be stabilized and pastures should be restored with the selected polycomponent grass mixtures in order to halt degradation processes, to improve the economic state, and to increase fertility of pasture ecosystem across large territories. The experiment on the study of the productivity of artificially created phytocenoses for the purposes of restoration and an increase in the productivity of natural pasture ecosystems was conducted on vegetation plots of Hydrological Complex of the Federal Science Center of Agroecology of the Russian Academy of Sciences. A grass mixture with participation of Agropyron cristatum L., Artemisia arenaria D.C., and Medicaga sativa L. and a yield capacity of 228.6–246.7 g/m2 appears to be the most promising for sandy substrates, as well as a grass mixture with participation of Agropyron cristatum L., Agropyrom elangatum Host.P.B., and Bromus inermis Leyss., which has a yield capacity of 184.4 g/m2.
PubDate: 2022-03-01
DOI: 10.1134/S2079096122010140

• Ontogenesis and Ontogenetic Structure of Local Populations of the
Astragalus holargyreus Bunge (Fabaceae) of the Narrow-Local Endemic Of
Kyzylkum

Abstract: Astragalus holargyreus Bunge is a narrow-local endemic of Kyzyl Kum. It grows in the outlier mountains of Bukantau. It has status 1 in the Red Book of the Republic of Uzbekistan (2019). The purpose of the article is to assess the current state of local populations. When describing ontogenesis, we used the method of Rabotnov (1950), Uranov (1975), and Local Plant Populations (1976). The structure of local populations was studied with the generally accepted method (Uranov, 1975; Tsenopopulyatsiya rastenii…, 1976). Local populations were characterized according to the classification of ontogenetic structure proposed by Uranov and Smirnov (1969); age and effectiveness were characterized according to L.A. Zhivotovsky (2001). The ecological density was determined according to W. Odum (1986). Relevés were carried out according to the standard technique on 100-m2 areas (Polevaya geobotanika, 1964). Astragalus holargyreus is a monocentric, vegetatively nonmotile, tap-root, herbaceous polycarpic with sympodially renewing, monocyclic shoots. The ontogenetic spectrum of the first local population is typical and reflects the biological characteristics of the species: a gradual increase in the life span in the pregenerative and generative periods, which culminates in the middle-aged state, and rapid aging with an absolute maximum in individuals of a middle-aged generative state. The proportion of individuals with an absolute maximum occurs in individuals of the middle-aged generative state (29.06%). The ontogenetic spectrum in the second local population does not coincide with the characteristic one, which is unimodal with an absolute maximum for virginal individuals (23.40%). The average density of individuals is 0.86 pcs. per 1 m2 in local population 1 and 1.17 pcs./m2 in CP2. The ecological density ranges from 1.28 to 2.76. According to the sum of the points of organism and population characteristics, all surveyed local populations are in a stable state. It is recommended that the habitats of the species(Bukantau ridge) should be introduced into the system of protected natural areas of the republic in order to preserve the natural population of Astragalus holargyreus.
PubDate: 2022-03-01
DOI: 10.1134/S2079096122010103

• A Series of Medium-Scale Environmental Maps of the Dzhizak Steppe of the
1970s (Prior to the Start of Reclamation Development)

Abstract: The natural conditions of the Dzhizak Steppe in the 1970s–1980s are analyzed in the article. We have compiled a series of maps for this period that reflect the natural diversity of the steppe prior to the start of its reclamation. The series of maps includes (1) a map of the lithological–geomorphologic zoning, (2) a soil map, (3) salinity maps, and (4) a map of gypsum-bearing soils. All of these maps have been compiled on a topographic map on a scale of 1 : 100 000 with aerial photography. We have identified 22 lithological–geomorphologic districts in the Dzhizak steppe assigned to five lithological–geomorphologic regions. Detailed maps of the soil salinity on a scale of 1 : 2000 were also compiled for the test plots. The series of maps is a kind of geoinformation system that characterizes the status of the soil cover in the Dzhizak steppe prior to its development. The article contains information about soil features in the delineated regions. It is shown that, prior to irrigation, the specified regions significantly differed in the history of their development, lithological structure, soil-cover pattern, the salt and gypsum content in soils, and, therefore, the reclamation properties. Analysis of the differences in the initial soil-reclamation status of the specified regions and districts enables a more reliable assessment of the advantages and disadvantages of the reclamation measures in different areas of the Dzhizak steppe when their natural features are taken into account.
PubDate: 2022-03-01
DOI: 10.1134/S2079096122010073

• Change in the Components of Steppe Geosystems in the Southwestern
Transbaikal Region with Climate Warming

Abstract: Climate change due to increased temperature, which has become a challenge for societal development around the world, has been and remains uneven for different regions. The work reports the results of an analysis of long-term data on air temperature, atmospheric precipitation, and moisture of deep freezing, mealy-textured calcareous chernozems (black-earth soils) of the Onon–Argun’ steppe of the southwestern Transbaikal region. It has been shown that the next successive dry period of 1999–2020 differs from the preceding one of 1965–1981 by a substantial increase in temperature and an uneven annual amount of atmospheric precipitation. Based on these parameters, the former is divided into two parts: a very dry, warm period and a wet, very warm period. For most of the driest period (2001–2011), the soil-moisture reserve was at a wilting level or lower. Environmental catastrophic events, such as a ubiquitous drying of tree stands and the disappearance of lakes, including the large Lake Barun-Torei, were observed. Beginning in 2012, the amount of atmospheric precipitations had increased, but this had little effect on the soil-moisture reserve and lakes in terms of the replenishment of their waters. As a result, the water area of another large lake, Lake Zun-Torei in the Torei Depression, had almost entirely disappeared by 2018. The bottoms of the desiccating lakes transformed into alkaline-sulfate sodium and alkaline-chloride-sulfate sodium solonchaks. Xerophiles were observed to enter the community composition in the herbaceous plant ground cover of the steppes, and the height and density of the latter decreased. The above-ground phytomass decreased by a factor of 1.5–2.
PubDate: 2022-03-01
DOI: 10.1134/S2079096122010036

• Evaluation of Changes in Native Vegetation Cover of Dust Sources in the
Southwest of Iran under Different Irrigation Systems and Rainfall Patterns
in Seedling Cultivation Areas

Abstract: Efficient use of rainfall and water storage is fundamental to rehabilitating and improving rangelands in arid areas. In this study, we evaluated the changes in the native vegetation cover of three regions (dust centers) of the south and southeast of Ahvaz under different irrigation systems and rainfall patterns following seedling cultivation. A native of five 100-m transects, each 50 m apart, were systematically established in the three selected areas. Around 180 fixed plots were installed along transects. In the two growing seasons of spring and autumn from 2018 to 2020, the coverage of native species was recorded. The Simpson and Shannon and dominance diversity indices were estimated using the PAST software. The results showed that in the selected areas, various irrigation methods along with rainfall caused significant positive changes in vegetation cover, the number of species, and diversity from 2018 to 2020. The results indicated a significant difference between the average dominance index, Simpson and Shannon indices, and vegetation cover, as well as the number of species in different years. This study has identified that due to the lack of water for surface irrigation, contour furrowing and pitting using an excavator is the best and cost-effective way to restore native species. In addition to creating a suitable hole for receiving irrigation water, this method provides better drainage of the area during the rainy season, providing a suitable substrate for the growth and germination of seeds of native plants.
PubDate: 2022-03-01
DOI: 10.1134/S207909612201005X

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