Arid Ecosystems最新文献

It was revealed by a remote monitoring that the interfluve of Eruslan and Maly Uzen and the Manych basin, which were located 600–800 km from each other, served as the most important spring-summer habitats and key trophic areas of the Caspian, Volga-Ural, and Cis-Ural subpopulations of the Demoiselle Crane (Anthropoides virgo, Linneaus 1758). These subpopulations nest from the Central Ciscaucasia to the Cis-Ural. Demoiselle Cranes of the Caspian subpopulation stay only in the Manych Basin during both spring-summer and trophic stage of migration, without flying outside this territory. Families from the Trans-Volga Region of the Volga-Ural subpopulation use both key areas during the trophic stage, whereas families from the Western Kazakhstan spend most of the trophic stage in the interfluve of Eruslan and Maly Uzen and move to the Manych basin before the start of the transit stage of an autumn migration. The total area of the territory that is used by Demoiselle Cranes in the interfluve of Eruslan and Maly Uzen, as well as in the Manych basin, was 6948.6 and 29457.2 km² respectively. The Volga-Ural subpopulation uses a larger territory in the Manych basin compared to the Caspian subpopulation, which adheres to the coastal zone of the Manych. Cranes which breed in the Manych basin are the first to begin the transit stage of a migration and their departure time is the most extended. The Demoiselle Cranes of the Volga-Ural subpopulation fly away at a later and shorter time.

The results of a study of long-term climatic conditions in the “ground layer of the air–soil” system in the island steppes of southeastern Siberia are discussed. It is noted that against the background of increasing severity of winters and continental climate of the surface atmosphere in the direction from northwest to southeast, winter cooling of the soil intensifies in the same direction, and summer warming increases slightly. Significant differences in the annual amplitude of soil temperature at depths in territorially separated island steppes were recorded. Its highest values are in Southern Transbaikalia, which corresponds to a sharply continental soil climate. Based on long-term series of the average annual air and soil temperatures and the amount of atmospheric precipitation per year, the trends in their changes in recent decades have been determined. The linear trends in air and soil temperatures are positive almost everywhere, and their long-term series are characterized by good consistency. Atmospheric precipitation in Southern Transbaikalia tends to decrease; in the Cis-Baikal region, the insignificant linear trend has both positive and negative signs.

The functions that determine physicochemical and biological processes that contribute to the development of soil formation and elements of the Land Registry are considered. Modern trends in soil development are characterized by intensification of use and reduction of their functioning areas. The mechanism of formation of objects of anthropogenic soil formation and elements of the Land Cadastre has been studied in the Terek–Kuma Lowland, which is one of the main regions of the Caspian Lowland, which is prone to desertification and aridization. The hierarchical system of objects of the Land Cadastre according to the scale of the functions performed is differentiated at the level of gradations of global, federal, and constituent entities of the Russian Federation and municipalities. The analysis of the elements of the Land Cadastre and their role in a multi-sectoral plan was carried out using the ecological–biosphere concept of soil formation, the fundamental basis of which boils down to the differentiation of objects into two groups: the sphere of objects of human economic activities, as a result of which land biomass is created and oxygen is produced using carbon dioxide for photosynthesis and the sphere of industries, housing construction, and transport communications, which consume biogenic energy and organic matter. In addition to the selected groups, the sphere of geological deposits is included. The technogenic cover, consisting of elements simultaneously performing the functions of cadastral registration and processes of anthropogenic soil formation, has been determined starting from detailed survey scales (1 : 100 and 1 : 1000). The cadastral burden at the most highly detailed scales of research creates a minimal burden. At the first stage of cadastral registration, the assessment is carried out covering individual areas and fields of crop rotation and the elements of the minimum size used when performing field work. At the second stage, larger objects are allocated as production units (crop rotation lands, team plots, and pasture rotation fields). The variety of objects of the Land Cadastre and their combination with the technosphere create a special structure of categories of biotic and abiotic natures that are ubiquitous on the earth’s surface. The emergence of a land cadastre and its assessment are determined by the production functions necessary to create favorable conditions for obtaining economic products. Cadastral objects act here as a factor of anthropogenic soil formation. Their influence is manifested in changes in soil properties: the temperature of the surface layers of the earth, the content of humus, the dry residue of easily soluble salts, volumetric weight, and water permeability. The cadastral content of the technogenic soil cover resulting from the influence of the anthropogenic factor is in a state of dynamic development due to two factors: the market economy and the direction of the arid type of soil formation.

Over the past half century, global warming has become one of humanity’s serious problems, which is accompanied by ecosystem reactions, that is, climate aridization and subsequent desertification of landscapes. In southeastern Transbaikalia (Dauria) and the bordering regions of Mongolia and China, the problem is intensified by regionally occurring cyclical (approximately 30-year) humid (transgressive) and arid (regressive) climate phases. In these territories there are more than 500 drainless salt and brackish lakes of various chemical compositions and varying degrees of mineralization. Naturally, all the ongoing climate changes are clearly reflected in the hydrology and chemical composition of these reservoirs and in the landscapes of lake depressions, including the soil cover. During the regressive climate phase, we conducted studies of the main types of soils in the lakeside depression of the pulsating chloride Lake Bab’e. Their morphology, particle size distribution, physicochemical and other properties, composition, and salinity chemistry were studied for the first time. It has been established that these soils form a genetically related series of saline soils: quasi-gley solonchaks of the chloride type of salinity–humus-quasi-gley saline soils–light humus saline soils. It was revealed that the formation of salt marshes is directly influenced by highly mineralized lake waters. Humus-quasi-gley saline soils formed in superaquatic positions are periodically affected by lake waters and are active only in the humid climate phase. Also, the research results indicated that in humus-quasi-gley and light humus soils, chloride–soda and soda-chloride salinization of the lower horizons was noted. The obtained materials will be necessary for monitoring saline soils and ecosystems of lakeside depressions of cyclically pulsating highly mineralized drainless reservoirs in the transboundary territories of Transbaikalia (Russia), Mongolia, and China during global and regional climate changes.

The lipid fraction of organic matter was first characterized for chestnut soils and quasi-gley chernozems of the Western Transbaikal region. ¹³С NMR spectra were acquired of lipid formulations of chestnut soils on the Selenga Highlands and quasi-gley chernozems in the south of the Vitim Plateau. Analysis of the spectra was performed, specifically, labeling of signals of ethoxy groups, phenol derivatives, and alkene fragments; indication of the chemical shift ranges characteristic of particular types of carbon nuclei; and comparison of the contents of various types of structural elements between the studied samples. The relationship was determined between the lipid components and hydromorphism of soils in quasi-gley chernozems. An increase in the degree of hydromorphism is presumed to lead to an increase in a share of unsaturated components.

The forest–steppe is an ecotone biome that has been greatly transformed by humans. Rodents are an important component of most forest–steppe biotopes. This group of mammals is distinguished by high species diversity and its representatives occupy many ecological niches. Rodents are also important to humans due to their impacts on agriculture, health, and other areas of life. The human impact on rodents is also multifaceted and complex, especially in the most heavily modified areas. In Russia, this includes the European part of the forest–steppe zone. The protection of rodents in the forest–steppe of European Russia, its effectiveness, and especially its current state require analysis. The protection of rodent species in this article is considered through the Red Books of the federal and regional levels, as well as through an analysis of the location of specially protected natural areas and the composition of their rodent fauna. Data on protected species and their status were extracted from the regional Red Books. The specially protected natural areas under consideration are briefly characterized. The participation of each rodent species in the fauna of these territories was analyzed. A map of the location of the areas under discussion and a table of the presence of rodent species in them have been compiled. The forest–steppe of European Russia is represented by three biomes: Dnieper–Volga, Zavolzhsky, and Crimean–Caucasian, in which 45 species of rodents were recorded, of which 35 are in the Dnieper–Volga biome, 27 in the Zavolzhsky, 27 in the Caucasian part of the Crimean–Caucasian biome, and 19 in the Crimean part of the Crimean–Caucasian biome. These biomes are located within 21 constituent entities of the Russian Federation. At the regional level, in the forest–steppe of European Russia, from 2 (Bashkortostan, Tula oblast) to 12 species of rodents (Chuvashia) are protected. There are 24 species that are protected in at least one region. One species is protected at the federal level, the speckled ground squirrel. In the forest–steppe of the European part of Russia there are 14 specially protected natural areas federal level: 7 nature reserves, 4 federal reserves, and 3 national parks, of which 9 have data on the species composition of rodents. A total of 33 species of rodents have been recorded in federal reserves. On each specially protected area from 11 (Voroninsky Reserve) to 26 (Belogorye) species were noted.

The materials presented in this paper are a continuation of studies on the early arable farming in Mongolia. Traces of multiple ancient agro-irrigation landscapes in Northwest Mongolia (Ubs Nuur Basin and western spurs of the Khangai) were discovered, as well as the associated settlements. The geological position of this territory, orogenic processes, and neotectonic shifts factored into the formation along the young rising mountain ranges of subaerial deltas favorable for the development of sai arable farming dated to an early stage of ancient irrigation. Initially, embanked channels of short-term streams of the subaerial deltas were transformed into rather extensive irrigated territories. In addition to the traditionally irrigated landscapes (subaerial deltas, deluvial–proluvial slopes, and floodplains), the field boundaries tended to peatlands and peat-containing soils formed in the basin of Lake Ubs Nuur, as well as peatlands formed as a result of the damming of Nariin Gol during the uplift of the Agardag Mountains. Since the territory of Mongolia belongs to a region of manifestation of young basaltoid magmatic activity, concentration of the ancient fields in immediate proximity to recent volcanoes (Khorgo (also Horgo), the Tes-Gol field) implies the use of fertile volcanic ash and natural heat in farming practices of the population. The presence of stela with a runic writing system dated to the second half of the 8th to early 9th century suggests the existence of arable farming in Northwest Mongolia during the Uyghur time period.

Based on the use of the SWAP land sutface model in combination with scenario projections of the dynamics of the daily values of meteorological characteristics in the territory of the Steppe Crimea until the end of the 21st century obtained using climate models with a spatial resolution of 0.5° × 0.5°, simulations of the components of the water balance and the characteristics of water availability for the region’s ecosystems were carried out for 1961–2100. The climatic values of the average annual near-surface air temperature, annual precipitation, evapotranspiration, surface runoff, underground runoff, real transpiration, potential transpiration, water availability for ecosystems and the efficiency of ecosystem use of soil water resources were obtained for the historical (1981–2010) and two projection (2031–2060 and 2071–2100) periods under different global climate change scenarios: SSP1-2.6, SSP3-7.0 and SSP5-8.5. An analysis of changes in these characteristics for the territory of the Steppe Crimea in the 21st century was carried out.