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Features of social vole spreading and survival in a clayey semi-desert of the Trans-Volga region. – Bykov A.V., Shabanova N.P., and Bukhareva O.A. – Social vole (Microtus socialis Pall.) is a landscape species of the Trans-Volga clayey semi-desert, which disappeared from the zonal plain in the 1970s but survived in various habitats of lake depressions. In 2009, it settled the blind plain again. No causes of voles going away and returning back are known. These phenomena might be one of cyclic changes in the specific composition and abundance of many animals in the region.
Key words: social vole, Microtus socialis, cyclical changes of specific composition, clayey semi-desert of Trans-Volga region, abundance dynamics.
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Changes in the specific composition and trophic structure of the soil population due to creation of artificial forest plantings in the Caspian semidesert. – Vsevolodova-Perel T.S., Sizemskaya M.L., and Kolesnikov A.V. – The influence of microrelief on the distribution of soil invertebrates in semidesert conditions is shown. Ways of soil mesofauna formation in the forest plantings created in mesodepressions at the Dzhanybek Research Station are considered. The results of earthworm introduction into oak plantings done above 40 years ago are summarized. The composition of the soil population and the character of the litter in artificial forest plantings and those in natural spiraea brushwoods are compared.
Key words: soil mesofauna, earthworms, forest litter, semidesert.
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Nitrogen cycle elements in the Northern Ciscaspian lowland landscapes. – Kulakova N.Yu. and Abaturov B.D. – The input of zoogenic nitrogen to desert-type biocenoses is generally lower than the nitrogen input due to plant residues (1.7 g/m2), but zoogenic nitrogen is distributed extremely ununiformly: at excrement-rich places (the exits of animal holes, about 1% of the whole territory) it is 17 times higher (up to 75 g/m2) than the vegetable nitrogen input. Zoogenic nitrogen (the excrements and liquid excreta of animals) weakly influences the mineral nitrogen content in the soil in the dry period.
Key words: nitrogen cycle, zoogenic nitrogen, nitrogen redistribution in semidesert landscapes, Spermophilus pygmaeus.
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Feeding of Social vole at the beginning stage of colonization of a zonal plain in a clayey semi-desert of the Trans-Volga region. – Larionov K.O., Bykov A.V., Vyshyvkin A.A., and Shadrina M.B. – The specific composition and fraction of various plants in the diet of Microtus socialis Pall. were determined by microhistological cuticular-coprological analysis of undigested remains. Microtus socialis disappeared from the zone plain of the Volga-Ural interfluve in the early 1970s and appeared again in 2009. The role of cereals in their nutrition has increased, and the fraction of wormwoods has sharply decreased. The noted features of nutrition are caused by the long-term absence of these mass phytophagues and reflect the essential changes in the environment occurred for 40 years.
Key words: Microtus socialis, phytophagues, feeding, environment change.
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Analysis of the microfabrics of reclaimed solonetzes at the Dzhanybek Research Station for evaluation of their ecological status. – Lebedeva (Verba) M.P. and Sizemskaya M.L. – Micromorphological studies of reclaimed solonchakous solonetzes at the Dzhanybek Research Station were performed with an interval of 20 years. Their analysis has allowed assessment of recent trends in the development of pedogenetic processes in these soils. Soil microfabrics and, particularly, salt pedofeatures were shown to be sensitive indicators of the processes and conditions at the interface between the solid soil mass and pore space. It was found that, for 20-year reclamation, the arable horizon of the reclaimed solonetzes became more homogeneous; the diversity and number of calcareous and gypsiferous pedofeatures in the soil profiles have decreased, and the ameliorative effect has become more pronounced.
Key words: evolution of reclaimed solonetzes, micromorphology.
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Renewal and conservation of trees and shrubs in artificial forests in arid regions. – Sapanov M.K. – The possibility of natural seed and vegetative reproduction of trees and shrubs in artificial forest ecosystems with different soil types was studied. The initial stage of secondary succession in the Northern Caspian lowland during the process of afforestation disintegration on semihydromorphic meadow-chestnut soils with accessible subsoil waters can go to form natural shrub-type forest ecosystems with stand-alone high trees. The structure of such ecosystems is very similar to that of ravine forests in the Volga and Ural river interfluve. In humid artificial relief depressions (e.g. in abandoned ponds and open-cast mines), ecosystems similar, by organization, to the riparian forests of Central Asia can be formed because of domination of Elaeagnus oxicarpa and white & black poplars.
Key words: arid regions, renewal of trees and shrubs, longevity, growth conditions.
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Climate-caused changes in the herbaceous vegetation on solonchakous solonetzes of the Northern Caspian lowland. – Sapanov M.K. and Sizemskaya M.L. – Essential steady warming of the cold season in the Northern Caspian lowland has been revealed. The humidity of the vegetative season has increased. Both these factors have caused general mesophytization of this territory. Due to this cause, the dominating plants on saline solonetzes have switched from Artemisia pauciflora to Kochia prostrata. However, these ecosystems remain in dynamically equilibrium conditions, so changes and wavy fluctuations of the plant productivity can be naturally reverted.
Key words: regional climate changes, arid ecosystems, monitoring, productivity, phytocenosis.
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Ecological features of forest growing in arid regions of Russia and China. – Sapanov M.K., Sizemskaya M.L., Kolesnikov A.V., Jiao Juying, Wu Qinxiao, and Liu Guobin – The conditions of forest growing in the south of the Russian Plain within the Southeastern European Russia and the Loess Plateau in China are compared. Common regularities and distinctions in the functioning of artificial wood ecosystems in these conditions have been revealed and ways of steady forest cultivation are planned. Additional humidifying due to redistribution of atmospheric precipitation is shown to be necessary for creation of durable forest plantings, the storm drain and snow & runoff redistribution being controllable in China and Russia, respectively.
Key words: forest growing, arid regions, humidity deficit.
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Role of the Dzhanybek oasis as a migratory stopover site for forest passerines. – Chernetsov N.S., Bulyuk V.N., and Ktitorov P.S. – In 2003 – 2005 we mist-netted birds at the Dzhanybek oasis in order to study: 1) what forest and aquatic passerines made migratory stopovers in the surveyed area; 2) whether the main stopover parameters in passerines that migrated towards different wintering quarters were different; 3) what was the role of the Dzhanybek oasis for refuelling of migrants; 4) what migration strategy was used by Palaearctic-African and Palaearctic-Indian passerines when crossing the northern Caspian semideserts. A total of 4862 individuals of 45 passerine species were captured (4493 individuals, 43 species in the autumn; 369 individuals, 18 species in the spring). In the autumn the most common passage migrants were European Robin, Common Redstart, Song Thrush, Garden Warbler, Chiffchaff, Willow Warbler, Red-breasted Flycatcher, Great Tit, and Blue Tit; in the spring these were Garden and Blyth's Reed Warblers. The Dzhanybek oasis is shown to be a good stopover and refuelling site for many forest-dwelling passerines during their autumn migration. In the spring, almost all birds stopped for one day only. This oasis is assumed to be less important as a stopover site in the spring than in the autumn. Palaearctic-African migrants that do not cross any significant barrier in this section of their migratory route have moderate body masses and fuel loads north of the Caspian Sea. Red-breasted Flycatchers that migrate to India carry no large fuel stores before crossing a wide barrier of deserts and highlands of Kazakhstan and Central Asia. Passerines captured with significant fuel stores seem to have accumulated them before crossing the arid zone, in a forest steppe where their optimal habitats are more common.
Key words: passerines, migration, stopover, ecological barrier.
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