Архив метки: number

CURRENT STATUS AND RETROSPECTIVE ANALYSIS OF SOME BIOLOGICAL PARAMETERS OF SAIGA POPULATIONS INHABITING TERRITORY OF RUSSIA AND KAZAKHSTAN

Arid Ecosystems

Karimova T.Yu., Lushchekina A.A., Neronov V.M. CURRENT STATUS AND RETROSPECTIVE ANALYSIS OF SOME BIOLOGICAL PARAMETERS OF SAIGA POPULATIONS INHABITING TERRITORY OF RUSSIA AND KAZAKHSTAN // Arid ecosystems. 2021. V. 27. № 2 (87). P. 57-67 | PDF

Since the beginning of the 20th century, the number of saigas (Saiga tatarica tatarica L., 1766) has sharply decreased twice as a result of human activity. But if for the first time the number of all four populations – the North-West Pre-Caspian, Ustyurt, Volga-Ural and Betpakdala – has recovered and by the 70-80s of last century there were more than 1 million heads, then the second time (since the beginning of the 21st century) an increase in the number of these ungulates was noted only for two populations – the Volga-Ural and Betpakdala. The aim of the study was to analyze the biological parameters of the four populations and to find out the differences that allowed saigas inhabiting the Volga-Ural interfluve and Betpakdala to overcome the depression phase and begin to recover their numbers. At the end of the 20th century, the economic situation in the states where saigas were widespread at that time led to an increase in poaching among the population, which led to a sharp decrease in the total number of these ungulates to 50,000. The area of the main range decreased 50 times for the saiga population of the North-West Pre-Caspian, 2.4-5 times for the other three populations. The length and mass of seasonal migrations also decreased, and the saiga population of the North-West Pre-Caspian has become practically sedentary. In the period of low numbers, all populations have shown a decrease in the number of herds of different sizes found throughout the year, and in 56-100% of cases, herds of up to 50 animals were registered. In the early 2000s, the main biological parameters characterizing the four saiga populations were comparable, with the proportion of adult males and the yield of young animals per female in July-August being higher than in the other three populations (11.5±1.9 and 0.81±0.18 vs. 8.7±3.8 and 0.48±0.40, respectively). The growth of the Volga-Ural and Betpakdala populations became possible primarily due to the organization of effective protection and education of the local people with the support of the state government and international funds, which allowed reduce the press of poaching significantly.

Keywords: saiga, number, spatial distribution, migration, population structure, fecundity.

DOI: 10.24411/1993-3916-2021-10151

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