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1.
Meiotic abnormalities have been studied in Siberian spruce growing in the Southern Urals under different ecological conditions: in contrasting natural landscapes (high mountains, plains, river valleys and floodplains), in zones of natural geochemical anomalies, and in areas with different levels of industrial pollution. The results provide evidence for an adverse effect of technogenic pollution and extreme environmental factors on the process of microsporogenesis in the species studied.  相似文献   

2.
The results of a karyological study on Siberian stone pines growing in the bog demonstrated differences from the populations of this species studied earlier with respect to sizes of chromosomes and location of secondary constrictions. The number of nucleolar organizer regions in the chromosomes of Siberian stone pine trees growing in the bog was larger than in other populations. A wide spectrum of chromosome aberrations was revealed, which had not been observed in this species before. These were genome and chromosome aberrations of various types, as well as structural aberrations accompanied by changes in the number of chromosomes. It is assumed that the aberrations in the karyotype of Siberian stone pine resulted from stressful conditions.  相似文献   

3.
Lists of macrolepidopterans inhabiting the Southern, Middle, and Polar Urals have been used for analyzing the relationship between the species richness of these insects with that of the families of plants on which their larvae feed. The results have shown that this factor in the Southern Urals accounts for approximately 75% and 65% of variation in the species richness of lepidopterans on woody and herbaceous plants, respectively. In the Polar Urals, this correlation is markedly weaker. Latitudinal trends in trophic preferences of individual lepidopteran taxa have been revealed. Probable causes of changes in the relative abundance of lepidopterans north of the forest zone are discussed.  相似文献   

4.
Changes in the abundance, species composition, and biomorphological structure of the carabid fauna were studied in birch and fir–spruce forests growing in a zone exposed to emissions from a copper-smelting plant in the Middle Urals. The dynamic density of carabids decreased and their species composition and the ratio of life forms changed along the pollution gradient, but the principle of organization of carabidocenoses and the structure of dominance in them remained undisturbed.  相似文献   

5.
The Macrolepidoptera fauna of the Urals, from the southern to the northern boundary of the forest zone (i.e., from the forest–steppe of the Southern Urals to the forest–tundra of the Polar Urals) has been analyzed. It has been demonstrated that the proportion of Lepidoptera feeding on woody plants, including evergreens, increases in this direction. Among the Heterocera, the proportion of species feeding on graminoids decreases; in the Polar Urals, none of these species is specialized. The food spectrum is particularly variable in noctuids and almost invariable in geometrids and Rhopalocera. It is assumed that foods with a low nutrient value (grasses, mosses, lichens, plant debris, wood, and roots of various plants) prevent Macrolepidoptera species from spreading in the Subarctic region. In the Polar Urals, multiyear developmental cycles and wintering at the larval stage are related to feeding on these types of food.  相似文献   

6.
The abundance of moles has been studied in 2007–2010 along the gradient of pollution by emissions from the Middle Ural (Middle Urals) and Karabash (Southern Urals) Copper Smelters. It has been estimated by the routing method with regard to the number of inhabited burrows per 1 km. Not a single mole has been recorded in heavily polluted areas near these copper smelters. Under conditions of moderate pollution, the abundance of moles decreased 1.5–1.8 times. The smallest “mole desert” near the source of emissions extends for 90–100 km2. A dramatic decrease in the abundance of earthworms, which are the main food object of moles, is considered a possible reason for these changes.  相似文献   

7.
Analysis of the effect of emissions from the Karabash Copper Smelter (Southern Urals) on the small mammal community has shown that its abundance and structure change significantly under technogenic impact. Structural transformations are accompanied by changes in the composition of dominant species. The “dose-effect“ pattern of community response to this impact is nonlinear: for most species of murine rodents and small insectivores, habitat quality becomes satisfactory at a distance of 9–11 km from the emission plume.  相似文献   

8.
Unique mountain-steppe ecosystems in the Southern Urals have retained a high level of species and cenotic diversity, despite fragmentation and isolation. Specific features of these ecosystems are described.  相似文献   

9.
A sequential extraction procedure was used to study localization of heavy metals in thalli of the lichen Hypogymnia physodes (L.) Nyl. growing under conditions of chronic aerotechnogenic pollution in the Middle Urals. Trends in the seasonal dynamics of metal contents in the thalli were revealed. The dynamics of metal accumulation was also studied in the thalli brought to the polluted zone from the background environment. After one year, the extra-and intercellular contents of most metals in these transplants approached those in the aboriginal thalli and in some cases (intracellular content of cadmium) exceeded them.  相似文献   

10.
An inventory of rock vegetation has been taken in river valleys on the eastern slope of the southern part of the Northern Urals and the northern part of the Middle Urals. New habitats of some rare plant species, relict communities of forest-steppe species at the northern limit of their distribution, and ultrasmall populations of petrophilous species growing in isolation for a long time have been revealed. In studies on a group of similar specially protected areas (e.g., within river valleys), it is proposed to identify key sites distinguished by the highest species richness of vegetation  相似文献   

11.
Variation in morphometric parameters of the poorly studied rare species Cephalaria uralensis (Murr.) Schrad. ex Roem. et Schult. has been studied at the northern boundary of its range, in the Southern Urals (Bashkortostan). The species in the region grows in four types of steppe communities of the class Festuco-Brometea. Variation in the majority of parameters is within the species reaction norm. The most variable parameters are the numbers of vegetative and generative shoots and the number of inflorescences per shoot. As shown by discriminant analysis, all 16 cenopopulations included in the study significantly differ from each other (Wilks’ λ = 0.21), with most of them being morphologically and structurally uniform. The state of local C. uralensis appears to be satisfactory, and this species is not at serious risk for extinction in the territory of Bashkortostan.  相似文献   

12.
Relationships between stem diameter and phytomass of trees and their parts (single- and multistemmed growth forms) have been studied at different altitudinal levels of the present-day upper treeline ecotone on the Iremel’ Massif, the Southern Urals. The time course of changes in the structure and phytomass of birch–spruce stands during the past centuries has been reconstructed. It is shown that the expansion of forests to the mountains in this period has occurred against the background of rise in summer and winter temperatures and increase in the amount of solid precipitation in the Southern Urals.  相似文献   

13.
Ecological and biological characteristics of Cyclachaena xanthiifolia (Nutt.) Fresen., have been studied in four regions of the Southern Urals and Cisural region. Communities including this species have been attributed to association Ivetum xanthiifoliae Fija?kowski 1967 of the class Stellarietea mediae R.Tx., Lohmeyer et Preising 1950. It has been shown that ecological habitat conditions have a significant effect on the majority of morphometric parameters of C. xanthiifolia, accounting for 1.3 to 51.4% of their total variance. Seed production averages 6500 seeds per plant. Extensive dispersal of the species over the Southern Ural region is predicted.  相似文献   

14.
Analysis has been made of changes in the species composition and abundance of epiphytic lichens on fir trees during the first decade after a sharp reduction of emissions from a large copper smelter in the Middle Urals. The results show that lichens have recolonized the area of the former lichen desert and that the abundance of lichen species in the impact and buffer zones has increased. However, a fairly long time is required before lichen communities in the vicinity of the smelter can recover to the background state, since species highly sensitive to pollution still occur only in the background area.  相似文献   

15.
Geometric morphometrics has been used to reveal coupled geographic variation in the mandible shape in two sympatric rodent species, the pygmy wood mouse (Sylvaemus uralensis Pall.) and bank vole (Myodes glareolus Pall.), in the Southern Urals. It has been shown that syntopic samples synchronously collected from the local communities of these species usually display similar, parallel, and unidirectional morphological changes as demonstrated by comparison of species pairs from different localities. The degree of concordance in geographic variation of the species makes it possible to estimate their coevolutionary potential within local communities: the wider the range of ecological conditions under which parallel variation of sympatric species is observed, the higher is their coevolutionary potential.  相似文献   

16.
Data on the abundance and occurrence of 64 odonate species in the Southern Urals are considered. A comparative analysis of the odonate fauna in the early 20th century, in the 1960s and 1970s, and in the early 21st century is performed. On this basis, it is concluded that its structure has been markedly changing with time, with the magnitude of these changes being comparable to that of regional faunistic differences. The causes of these changes are discussed. The apparent enrichment of the odonate fauna is attributed primarily to the appearance of new anthropogenic habitats.  相似文献   

17.
A method for estimating floristic diversity at the species, genus, and family levels and the taxonomic structure of the flora of protected natural areas is proposed. The method is illustrated using the example of three nature reserves located in the Northern, Middle, and Southern Urals. The dependence of the characteristics of the regional floras on their positions in the system of botanical–geographic zones, the size of the protected area, and other factors have been studied in these reserves. The proportion of endemic plants and the degree of flora synanthropization have been determined.  相似文献   

18.
Trends in the proportions of plants differently interacting with mycorrhizal fungi in the course of pasture digression have been analyzed in the steppe zone of the Southern Urals. Estimates of species richness and abundance of plant groups with different mycorrhizal status have been obtained by comparing original data on the structure of phytocenoses with published data on the ability of plant species to form mycorrhizae. It has been shown that the proportions and abundance of obligate mycorrhizal species decrease significantly in the course of digression, with consequent increase in those of species less dependent on or independent of symbiosis with fungi, i.e., facultative mycorrhizal or obligate nonmycorrhizal plants.  相似文献   

19.
New data are presented on unique refugia accounting for the high floristic diversity of dark conifer forests of the Northern Urals, which have some of the highest parameters of species saturation among boreal forests of northern Eurasia. Based on the results of analysis, the most significant biological factors have been revealed and their influence on boreal tall-herb and background plant communities has been evaluated.  相似文献   

20.
On the basis of studies on the ecology of boreal bat species in the Southern Urals (1997–2004), the first classification of their summer habitats has been made. It has been shown that spatial segregation of sex groups into areas of two types, designated wintering and breeding zones, takes place in populations in the period of offspring rearing. In females, seasonal migrations are guided by imprinting on sites providing sufficient food for offspring rearing and on wintering sites. In males, imprinting on wintering sites alone is observed.  相似文献   

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