Архив рубрики: article-3-2020

THE CLIMATIC FLUCTUATIONS IN DRY STEPPES AND THEIR ROLE IN THE PROCESS OF REGENERATION

Arid Ecosystems

Pugacheva A.M. The Climatic Fluctuations in Dry Steppes and Their Role in the Process of Regeneration // Arid ecosystems. 2020. V. 26. № 3 (84). P. 14-22. | PDF

For the first time a research paper presents the results of the analyses of moisture-providing during the active growing seasons in dry steppes. The climatic fluctuations were examined together with the defining their characteristics. Contrary to the common opinion, that the steppe zone receives the highest rainfall in summer and that fact becomes its special feature including subzones, the analyses of 64 years show that the dry steppes of Lower Volga region received the highest rainfall in summer only in 39 % of years, in spring – in 27% of years and in autumn – in 34% of years. The time-series analysis during the seasons of moisture-providing for more than 50 years identified the general trend of decrease in summer rainfall and the increase of spring and autumn rainfall. The processing of time-series by  exponential smoothing and the regression analysis points to the rate of humidity increase in spring after the critical years of 1990 and 1991, which is proved by Student’s t-test (probability 0,00005) together with the humidity decrease in autumn (probability 0,01). These features characterize the regeneration processes of secondary phytocenoses on fallow lands in the form of domination of loose bunch cereaks and dense cereals in them because the moisture-providing in late spring (May) and early summer (June) has the primary importance for their development. In addition, the characteristics of moisture-providing show a tendency towards aridization. The number of species of Poaceae family  in the examined phytocenoses is 28 with 24.5% of representation. Moreover, this fact characterizes the existence of ephemeral plants and ephemeroids in the plant community, because their vital activity mainly depends on the spring rainfall. The number of their species is 8% of the total.

Keywords: climatic fluctuations, dry steppes, regeneration, plant communities, phytocenoses, exponential smoothing, regression analysis.

DOI: 10.24411/1993-3916-2020-10102

ANALYSIS OF CLIMATIC CONDITIONS IN THE REPUBLIC OF KALMYKIA FOR THE PERIOD 1966-2017

Arid Ecosystems

Shumova N.А. Analysis of climatic conditions in the Republic of Kalmykia for the period 1966-2017 // Arid ecosystems. 2020. V. 26. № 3 (84). P. 23-29. | PDF

The work is based on an analysis of the dynamics of air temperature, precipitation and the hydrothermal coefficient of Selyaninov for the period from 1966 to 2017 based on data from the Yashkul meteorological station (Republic of Kalmykia). The construction and analysis of difference integral curves made it possible to identify periods with increased (in comparison with the average) and reduced values of the studied quantities. It is concluded that the leading role belongs to precipitation in the formation of hydrothermal conditions of the territory for the studied time interval and humid warming.

Key words: air temperature, precipitation, hydrothermal coefficient of Selyaninov, humid warming, Republic of Kalmykia.

DOI: 10.24411/1993-3916-2020-10103

GEOECOLOGICAL ZONING OF NORTHEASTERN CASPIAN REGION

Arid Ecosystems

Tabelinova A.S. Geological Zoning of Norteastern Caspian Region // Arid ecosystems. 2020. V. 26. № 3 (84). P. 50-58. | PDF

An analysis of the function of Northeastern Caspian region landscape structure in context of geological processes development is presented in the paper. The aim of investigation was the geoecological zoning based on studying the main factors defining specific direction and intensity of development in modern landscapes of the Northeastern Caspian Sea region: altitude-landscape and geomorphological differentiation of the territory generated during the long-term development of the region, significant fluctuations of Caspian Sea level and the evolution of anthropogenic activities including oil extraction. Spatial differentiation of geoecological processes into landscapes of Northeastern Caspian region was mapped based on studies of such processes at the different anthropogenic modifications of six key plots. Detection of spatial distribution of geoecological processes in the landscapes of studied region was based on direct and indirect interpretation indicators of Landsat 5 and Landsar 7 multiband synthesized satellite images. GIS-mapping made possible to prepare the map of geoecological regions of Northeastern Caspian region. 25 geoecological regions and 127 subregions were mapped according to spatial structures (subspecies of modern landscapes) and anthropogenic factors defining geographical distribution and domination of specific geoecological processes.

Key words: geoecological regions, geoecological processes, modern landscapes of the Northeastern Caspian region, Landscape levels.

DOI: 10.24411/1993-3916-2020-10106

THE ROLE OF THE MODE OF USE OF THE ECOSYSTEM IN THE STRUCTURE OF VARIABILITY OF SOME ELEMENTS OF SEED PRODUCTIVITY OF ENDEMIC OF DAGESTAN – ASTRAGALUS FISSURALIS

Arid Ecosystems

Habibov A.D., Mallaliev M.M. The Role of the Mode of Use of the Ecosystem in the Structure of Vasiability of Some Elements of Seed Productivity of Endemic of Dagestan – Astragalus Fissuralis // Arid ecosystems. 2020. V. 26. № 3 (84). P. 69-70. | PDF

A comparative analysis and assessment of the structure of variability of eight (dimensional, numerical, weight and index) features of seed productivity of two different heights (1100 and 1750 m above the SD. M.) populations of vegetative rolling stock representative of the woody flora and endangered shrubs RF and RD – Astragalus fissuralis Alexeenko (Fabaceae) from the middle mountain belt middle of mountain Dagestan are presented. The work was carried out at the population level. As a result of the summary statistics, correlation and dispersion analyses, the differences in the average indicators of the features and the impact of the anthropogenic factor – the mode of ecosystem use on the variability of these features of seed productivity, directly related to the adaptive strategy, were identified and evaluated. It is established that in the relatively unfavorable natural conditions plants of this rare species develop relatively short beans with a small (one or two) number of seeds, but they are larger than seeds of the introducers. At the same time, in natural conditions, in contrast to protected areas, the share of weight characteristics associated with the adaptive (reproductive) strategy and the effectiveness of reproductive efforts is increasing (the mass of seed and seeds from the fetus, the share of seed mass from the fetus allocated to reproduction itself).

However, it is marked that in the relatively better conditions of introduction of plants of this endemic of Dagestan and Russia, both of different heights (1750 and 1100 m above sea level. m) the sections of the experimental bases of Mountain Botanical garden, Dagestan Federal Research Centre of RAS develop vegetative mass, increases its dimension (long fruit), numeric (increases the number of relatively light and small seeds) and, consequently, the weight (the fruits become heavy) signs. In other words, when introduced, the development is obtained by the size (geometric values) of the fruit, and in natural conditions – weight (physical indicators) signs of the bean and seed. It is established that the variability of these features of the generative sphere is significantly affected by the mode of use of the ecosystem and the strength of the influence of this anthropogenic factor ranges from 23.6 to 79.3 %.

Keywords: Astragalus fissuralis, characteristics of seed production, size, weight, number, and index signs, fruit, seed, summary statistics, correlation and variance analyses.

DOI: 10.24411/1993-3916-2020-10108

ONTOGENETIC STRUCTURE OF RARE SPECIES ON THE USTYURT PLATEAU IN UZBEKISTAN

Arid Ecosystems

Rakhimova Т., Rakhimova N.К.,  Shomurodov Kh.F.,  Abduraimov О.S. Ontogenetic Structure of Rare Species on the Ustyurt Plateau in Uzbekistan // Arid ecosystems. 2020. V. 26. № 3 (84). P. 71-78. | PDF

The research assesses the state of the ontogenetic structure of some rare species (Rosa laxa Retz., Crataegus korolkowii L. Henry, Artemisia terrae-albae Krasch. and Salsola arbusculiformis Drob.) growing on the Karakalpak part of Ustyurt. The study shows that the studied cenopopulations are normal and mostly incomplete under the ecological and cenotic conditions of Ustyurt. The ontogenetic spectra of specific cenopopulations are left-sided and centered, which associated with the environmental living conditions and fluctuations in weather conditions. The similarity of biological features (long-term life expectancy of individuals in a middle-age ontogenetic state, the least elimination, and difficult seed germination) in individuals of different species and the actual, ontogenetic spectra with a characteristic spectrum indicates a stable state of the studied cenopopulations on the Karakalpak part of Ustyurt.

Key words: Ustyurt plateau, infrastructure development, endemics, rare plant species, ontogenetic structure, age and efficiency of cenopopulations.

DOI: 10.24411/1993-3916-2020-10109

THE STATE OF DESERT PHYTOCENOSES AT THE SITES OF LAUNCH VEHICLES ACCIDENTS IN THE REPUBLIC OF KAZAKHSTAN

Arid Ecosystems

Lednev S.A., Semenkov I.N., Koroleva T.V.,  Sharapova A.V. The State of Desert Phytocenoses at the Sites of Launch Vehicles Accidents in the Republic of Kazakhstan // Arid ecosystems. 2020. V. 26. № 3 (84). P. 79-87. | PDF

The article describes the vegetation cover formed after 4-12 years at three places of accident fallings of launch vehicles that use toxic compound unsymmetric dimethylhydrazine (UDMH) as a fuel component. The crash of a launch vehicle is accompanied by chemical, mechanical and thermal (or pyrogenic) effects on vegetation cover, which extends to different distances from the center of impact site and forming typical zones of technogenic disturbances. To characterize the vegetation cover we performed geobotanical descriptions at three sites of launch vehicles accidents that occurred in 2006–2013. Vegetation were characterized at plots located at different distances from the center of the impact site. A special feature of the overgrowth at the studied sites is the formation of communities of annual saltworts (Climacoptera lanata, Salsola laricina, S. paulsenii, etc.) with a relatively high projective cover at the site of the former crater due to subsidence of the ground and redistribution of surface runoff. With the distance from the center of the impact site the processes of demutation (self-restoration) of the initial vegetation performs: the participation of annuals within phytocenoses decreases, the total projective cover and floristic richness of plant communities increase. Self-restoration of phytocenoses without biological remediation may lasts at least 15 years according to the most optimistic forecasts.

Keywords: launch vehicle, technogenic impact, overgrowth, ruderal annuals, secondary succession, Kazakhstan.

DOI: 10.24411/1993-3916-2020-10110

DECOMPOSITION OF RICE STRAW BY WOODLICE (ISOPODA, ONISCIDEA) AND MILLIPEDES (MYRIAPODA, DIPLOPODA) IN THE SOILS OF KALMYKIA IN A LABORATORY EXPERIMENT

Arid Ecosystems

Lebedev Yu. M. , Gongalsky K. B. ,  Gorbunova A. Yu.,  Zaitsev A. S. Decomposition of Rice Straw by Woodlice (Isopoda, Oniscidea) and Millipedes (Myriapoda, Diplopoda) in the Soils of Kalmykia in a Laboratory Experiment // Arid ecosystems. 2020. V. 26. № 3 (84). P. 88-92. | PDF

Rice crop residues are one of the most difficult to decompose agricultural wastes in arid ecosystems. A laboratory experiment was carried out on the decomposition of rice straw by woodlice and millipedes, inhabiting dry steppes of Kalmykia (Russia). Five individuals of each of two species of woodlice (Armadillidium vulgare and Protracheoniscus kryszanovskii) and two species of millipedes (Brachydesmus assimilis and Cylindroiulus sp.) were placed in microcosms with soil and 2.5 grams rice straw amended. Straw mass significantly decreased for all species by approximately 50% on average within 4 months of the experiment duration. The content of organic matter in the soil before and after the experiment has not significantly changed, which allows us to suggest that selected species of woodlice and diplopods consume and thus utilize rice straw at least in experimental conditions.

Keywords: Biodegradation, Isopoda, Diplopoda, crop residue recycling, recalcitrant organic matter.

DOI: 10.24411/1993-3916-2020-10111