Arid Ecosystems最新文献

This work is devoted to assessing the features of the distribution of spatiotemporal changes in the characteristics of the minimum 30-day winter flow of rivers in the basin of Lake Sevan. The problem of spatiotemporal changes in the minimum river flow is especially relevant for regions with insufficient and unstable moisture, like the basin of Lake Sevan, most of which is located within the steppe zone. The purpose of this work is to summarize modern ideas about the impact of climate change on the characteristics of the minimum 30-day winter river flow based on the authors’ own research, to analyze and evaluate the spatiotemporal variability of long-term fluctuations, and to identify nonstationarity in the series of minimum winter flow. The characteristics of the minimum flow have been determined, their spatiotemporal changes have been studied, and the dates of violations of homogeneity in the series of long-term runoff observations have been discovered. Using statistical parameters and difference integral curves, we assessed the representativeness of time series of minimum 30-day winter water flows at 12 sites during the period of instrumental observations. Nonstationarity in the series of minimum winter runoff in the basin of Lake Sevan has been revealed, and the dates for changes in stationary regimes have been determined. For most of the watersheds analyzed, the changes are statistically significant. Maps of the date of violation of the stationarity of the series under consideration based on information up to 2021 are presented, including a map of the distribution of the module of the minimum 30-day runoff for the winter period and maps on the nature of changes in the minimum 30-day winter flow. It is shown that changes in the minimum 30-day winter flow have a multidirectional nature, but mainly for the minimum 30-day winter flow, on average, over the territory of the lake basin. In recent decades, Lake Sevan has shown an increasing trend associated with rising air and soil surface temperatures. For some of the watersheds analyzed, the changes are statistically insignificant. On the territory of the Vardenis, Lichk, and Bakhtak river basins, on average, the minimum 30-day winter flow decreases by 20–30%, which will lead to an increase in environmental risk, requiring the adoption of appropriate measures. The obtained statistical materials will serve as the basis for scientific generalizations of research on the territory under consideration and can also be used for practical purposes in hydraulic engineering design and assessment of natural hazards and in making appropriate preventive decisions.

Information on the state of the nesting population of some species of the order Charadariiformes (Charadriiformes) based on our own expeditionary and published data obtained during the study of bird species of the marsh-near-water complex, which is the most sensitive to changes in the water regime of reservoirs in the southern European part of Russia (using the example of artificial reservoirs of the Republic of Kalmykia), due to increased anthropogenic pressure and climate change is provided. An analysis of the impact of the water factor (drainage/watering of the reservoir) on the nesting population of some representatives of the Gull family (Laridae) is given. Information is provided on the features of the nesting ecology of the most typical nesting species of this taxonomic group for the study area, and their general quantitative indicators and population dynamics for the period 2011–2015 are given. The contribution of the reservoirs of the Sarpinskaya lake system and Deed-Khulsun Lake to the preservation and enrichment of biodiversity of the region was assessed. Recommendations are given for managing their hydrological regime in order to maintain and preserve populations of rare and vulnerable bird species.

The use of background indicators for monitoring the content of nutrients in surface and groundwater in the steppe and forest–steppe zones of the Russian Plain is substantiated. Approaches to determining the background content of nutrients are proposed. The peculiarities of the formation of the runoff of nutrients during the flood period and summer–autumn and autumn–winter periods are revealed. It is advisable to use the results obtained to assess anthropogenic changes in the content of ammonium nitrogen, nitrate and nitrite nitrogen, and mineral phosphorus in the surface water and groundwater, as well as in wastewater. It is shown that it is advisable to adjust the standards for the content of nitrates and ammonium nitrogen in river and waste waters taking into account the level of the regional natural and anthropogenic background.

Mathematical modeling is considered as a method for studying the dynamics of grassland soil and plant systems in arid zones of Russia. The evolutionary development of grassland phytocenoses was modeled using the principles of nonequilibrium thermodynamics based on continuous and discrete mathematical formalisms. Examples are given, and problems of sustainable development of such systems under conditions of anthropogenic load and climate change are discussed. This study demonstrates new methodological capabilities of mathematical models of different types: in the form of systems of ordinary differential equations and discrete Markov chains. Prediction of degradation processes occurring in grasslands using these models has been studied in a comparative aspect. Differential models with constant and variable coefficients showed different results due to the nonlinearity of succession dynamics. The model with constant coefficients was refined by introducing time-dependent coefficients. The stability of the functioning of grassland ecosystems is discussed from the point of view of the formal parametric stability of solutions for a system of ordinary differential equations. Discrete modeling using the Markov chain technique showed that the degradation of soil and plant systems when the animal load is exceeded is described by a heterogeneous Markov process. Homogeneous Markov chains give adequate forecasts on one observation time interval. Prediction of the final states in the homogeneous approximation revealed that the observed nonlinearity in the dynamics of phytocenoses was caused by changes in the rate of development, ultimately leading to heterogeneity of the Markov chain. The issues of modeling nonlinear processes in the ecology of grassland soil and plant systems in the context of heterogeneous Markov processes are discussed.

The basis of Russia’s natural reserve fund consists of federal state reserves, national parks, and wildlife sanctuaries, the representativeness of which in relation to the diversity of natural complexes, including soils, is the main mechanism for protecting natural diversity. Using the method of geoinformation analysis, the areal and typological representation of the natural diversity of steppe soils in the system of specially protected natural areas (SPNAs) of the country was assessed based on vector maps: Pochvennaya karta Rossii (Soil Map of Russia) on a scale of 1 : 2 500 000 (a combined version of the Pochvennaya karta RSFSR (Soil Map of the RSFSR) and the Pochvennaya karta Kryma (Soil Map of Crimea) and the Karty pochvenno-ekologicheskogo raionirovaniya v Rossiiskoi Federatsii (Map of Soil-Ecological Zoning of the Russian Federation) on a scale of 1 : 8 000 000. The area occupied by steppe soils in Russia is 1 564 000 km² (9.4% of the total soil area of the country), of which 7.4% are soils of steppes (including forest–steppes and true steppes) and 2.0% are soils of dry steppes and semideserts. In protected areas, steppe soils occupy 11 500 km² and are found in 23 nature reserves, 14 national parks, and 13 wildlife sanctuaries. The current areal representativeness of protected steppe areas is very low: less than 0.5% for the group “Soils of the steppes” and about 2% for the group “Soils of dry steppes and semideserts. “Of the 55 steppe soils, units of the legend of the “Soil Map of Russia,” 58% are represented in federal protected areas, while reserves, which account for a fifth of the total area of steppe protected areas, provide 81% of the typological representativeness. Currently, many natural steppe soils in Russia, including the most fertile ones, are not represented in protected areas. The most significant compact array of such soils in terms of area is located in Ciscaucasia. The largest area here is occupied by southern and ordinary mycelial–carbonate chernozems (World reference base for soil resources (2014) – Calcic Сhernozems (Pachic)), their area is about 98 000 km² (7.9% of the soil area of the Russian steppes). There is a real threat of losing the last virgin examples of highly fertile soils typical of Ciscaucasia: southern and ordinary chernozems, dark chestnut, chestnut, light chestnut soils (WRB – Calcic Сhernozems (Pachic), Haplic Kastanozems, Calcic/Gypsic Kastanozems, Luvic Calcisols). Preservation of these soils in the virgin state, at least as samples for comparison with anthropogenically modified analogues, requires an inventory of all areas of their distribution and assignment of a protective status.

The state of the invasive species Dreissena polymorpha (Pallas) was studied in Ivan’kovskoe (Ivan’kovo) Water Reservoir in 2018–2022 to obtain the quantitative parameters of the mollusk development at the larval and definitive stages in all pleses (moderately wide stretches of a water body that is deeper compared to the surrounding waters) of the water reservoir during different seasons, as well as to show the interannual dynamics of their population size and spatial distribution. In the Ivan’kovo Water Reservoir, the southern invasive species Dreissena polymorpha (Pallas) has adapted rather successfully and has occurred continuously in the subsaline water conditions with a persistent lack of dissolved oxygen in summer in the near-bottom waters, which caused a shift in the mollusk niche down to a depth of 4 m; the mussel did not occur in silty biotopes. Range expansion of the southern immigrant D. polymorpha to the northern regional water bodies is influenced by climate warming, which prolongs the reproductive process of this mollusk. Currently, the end dates of mussel spawning in the Upper Volga water reservoirs approach those in southern water bodies. Eutrophication enhancement due to climate changes may pose a serious threat to Ivan’kovo Water Reservoir. Overall, the mussel population (adult mollusks + veligers) play a significant role in the process of self-purification of the water reservoir.

Dust storms and dry haze are an unfavorable meteorological factor for the cities of the Aral Sea Region. The mean annual number of days with haze in Central Asian cities ranges from 10 to 20. Dust makes poorer the aspect of areas, but its impact on urban planning has been incompletely studied and the content of fine dust particles in the air of cities has not been monitored. The Afghan wind (garmsil: fiery, hot, dry wind with dust), which attracts particular attention, is a dust storm that suddenly starts in the deserts of Afghanistan and on the dried bottom of the Aral Sea (it is now called Aralkum (the Turkish kum signifies sand)). This is a real salt desert, containing pesticides and chemicals dangerous for human health. They penetrated rivers as fertilizers used by people and then flowed into the sea. They now cause significant damage to the cities and to the economy of Central Asian countries. Wind transport of dust from natural sources and, as a result, the dustiness of the urban environment are analyzed in this article. This problem is particularly urgent for most large cities in Central Asia, but has not been studied sufficiently. The dust factor is not sufficiently taken into account, when making urban planning decisions even in areas with intensive wind and dust activity, such as the Aral Sea Region, where it is related to natural and climatic conditions. More and more cool agricultural lands are now destroyed and used for building construction in many cities, which may exert a strong effect on the quality of life in the next few years. Not long ago, dustiness was considered only as a factor that creates uncomfortable conditions, but today, it is associated with morbidity and mortality of the population. A high dust content in the air harms landscaped areas, along highways and streets in particular. The protection of buildings from direct sunlight and dust consists in the use of sun protection devices, panels, and ventilated facades. One of the modern trends in architecture consists in the introduction of the technology of kinetic facades, which are formed of elements of different shapes and materials. When the proposed methods are implemented, there is a real opportunity to improve the quality of atmospheric air in cities located in complicated landscape conditions, which will directly affect the improvement of human health.

The state of the lakes of Southeastern Transbaikalia is assessed. The formation of the hydrochemical and hydrobiological regime of water bodies in the study area occurs under semi-arid climate conditions. The existing cyclical climate fluctuations with a periodicity of 27–35 years cause their sequential filling and drying out. These works were carried out during the transition period between low-water and high-water years. The abiotic environmental factors and chlorophyll a concentrations of various phytoplankton divisions, such as green algae, cryptophytes, diatoms and cyanobacteria, are considered. This work was carried out using a FluoroProbe submersible probe (bbe Moldaenke GmbH, Germany). It was established that the observed fluctuations in the level regime of lakes affect abiotic indicators, causing changes in the content of chlorophyll a of phytoplankton. The principal component analysis showed that the chlorophyll content of green algae depends on the content of potassium and sodium, bicarbonates, and chlorides. The chlorophyll content of cyanobacteria depends on the concentrations of calcium and magnesium. The chlorophyll content of cryptophyte algae depends on the depth of water bodies. Thus, changes in water levels in lakes affect the hydrochemical composition, which determines the structure of phytoplankton communities. Consequently, changes in the abiotic conditions, influencing the development of primary producers, are manifested in changes in the pigment composition of phytoplankton. Currently, most of the studied reservoirs are passing through the stage of mesotrophic level of their development.

The steppe marmot (baibak) is one of the typical rodents of the Eastern European forest–steppe and steppe. In the mid-twentieth century, European populations of the species were on the verge of extinction, but then, thanks to conservation measures and reintroductions, the population of boibak and range were largely restored. This work collects and presents data on two restored marmot colonies in the forest–steppe of European Russia. The research was carried out in the Central Black Earth Nature Reserve (Streletskaya steppe, two sections) and in the Volga Forest–Steppe Nature Reserve (Ostrovtsovskaya forest–steppe, three sections). The number and age composition of marmots are described. Maps of settlements with burrows and trails of marmots have been compiled; for each burrow the coordinates and type (temporary or permanent) are indicated. The population density and the number of burrows per marmot were calculated. In total, 12 marmots live in the Streletskaya steppe: ten on the “Pasture” site and two on the “Restored Steppe” site. In the first area, seven adult and three young marmots were noted, in the second, two adult marmots. Here, the reintroduction of the boibak was not entirely successful. From 2015 to 2023 the number of marmots decreased sharply, from 38 to 12 individuals, and the area of the inhabited territory fell from 10 to 3.7 hectares. In the Ostrovtsovskaya forest–steppe, 48 marmots (eight families) were recorded, of which 40 were in the first area (six families), two were in the second area (one family), and six were in the third area (one family). Of the 48 individuals, 29 (61%) are underyearlings. The reintroduction of the bobak into the Ostrovtsovskaya forest–steppe was relatively successful: the total number of animals is comparable to the number of marmots initially released (48 and 64).

A comprehensive study (vegetation and animal population) of biota and ecological differentiation of biotic cover with the widespread use of the cartographic approach is one of the central areas of modern biogeography. Its tasks include identifying ecological and geographical patterns of differentiation of biotic cover and identifying territorial units of different ranks for the purposes of inventory and conservation of biological diversity. One of the levels of regional research is relatively new and insufficiently covered in the domestic literature—the biome level. The biotic part of biomes consists of two components, the vegetation and the animal population, which is currently characterized by the population of birds and mammals as the most studied zoological taxa that have reached the stage of cartographic maturity. Issues such as the definition of a regional biome, the criteria for its identification, and the characteristics of its geozoological part are in the stage of study and development. The role and place of cadastral reference zoological maps in the biome concept as the basis for collecting, storing, and analyzing information about the spatiotemporal characteristics of communities is shown. Using the example of a model territory—the Ural biomes—experience-tested methods for presenting local theriological accounting data on a cadastral reference map and in the cadastre are proposed. The shortcomings in the presentation of field research results that complicate their interpretation are noted. The role of cadastral reference maps for planning zoological research, for compiling an objective description of the zoological component of regional biomes, and for justifying the boundaries between biomes is shown.