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1.
The variation of carbon and oxygen isotope composition in the carbonate group of carbonated hydroxyapatite from the incisor teeth has been studies in six recent rodent species trapped in different latitudinal regions of the Urals. Specific features of variation in the carbon and oxygen isotope ratios are discussed in dependence of animal’s species identity, typical environment, mode of life, dietary features, and ambient air temperature.  相似文献   

2.
The distribution of life forms in the dendroflora of the Russian Far East is discussed in connection with decrease in heat supply in the latitudinal (south-north) direction and the influence of the ocean in the longitudinal (east-west) direction. Emphasis is made on the uniqueness of the ratios between different life forms of the dendroflora at local and regional levels of the structural-functional organization of vegetation, which may be used for the purposes of environmental monitoring.  相似文献   

3.
The abundance of Orchidaceae on three calcareous grasslands is studied in relation to floristic composition, environmental and vegetational factors and plant traits (ecological and life forms). The aims are: (i) to identify a group of species that is significantly correlated with the abundance of Orchidaceae or with individual species of orchids on calcareous grasslands; (ii) to study the relationship between traits associated with habitat specialisation, community life forms and the abundance of orchids; (iii) to identify the main environmental and vegetational predictors of the abundance of orchids. A shortlist of species is found to be significantly correlated with the abundance of total orchids, Orchis pauciflora and O. morio. The life forms of the community species do not show any correlation with the orchids, with the exception of Orchis pauciflora, which tends to increase in communities rich in hemicryptophytes and poor in annual species. Analyses of Orchis morio seem to suggest that it has a high level of ecological tolerance. The most important predictors of the abundance of orchids are the substrate reaction (basic) and arid grassland with low herbaceous vegetation cover (i.e. high soil reaction and luminosity values, positive correlation with the cover of lichens and rockiness, negative correlation with tree cover and herbaceous layer). The least favourable sites were the least basic and most superficial and arid sites.  相似文献   

4.
A comparative analysis of epigenetic variation has been performed in nine European populations and population groups of the American mink. It has been shown that differentiation of samples in nonmetric characters is due mainly to endogenous processes that have occurred in introduced populations in the course of colonization of new territory by the invasive species. Environmental factors have played a secondary role, with the influence of the geographic (latitudinal) origin of a given sample being considerable and stronger than that of macroclimatic factors.  相似文献   

5.
The aim of this study was to determine whether the latitudinal distribution of fish species that use estuaries to complete their entire life cycle has shifted northward as an expected consequence of global warming. The mean latitude of past fish species distributions found in 1970s’ literature was compared with the mean latitude of distributions today based on fish density indices collected in 55 tidal estuaries along the Atlantic European seaboard, from Portugal to Scotland. Among the 15 most common species, 11 displayed a positive difference between current and past mean latitudes suggesting a northward shift of the populations. Using the occurrence of subtropical species in temperate areas as an indicator of water warming, the northernmost range limit of 10 subtropical species was subsequently focused on. Six of them were recorded up to their past northern latitudinal limit. These results reinforced the idea that a number of fish species associated to estuaries have migrated northwards over the last 30 years, possibly due to water warming. These ecological changes can get important managerial implications, i.e. in the assessment of the ecological status in European directives.  相似文献   

6.
Morphological trait variation in populations of rhizomatous (Cypripedium calceolus, Listera ovata) and root-tuber orchid species (Platanthera bifolia, Gymnadenia conopsea) has been studied along a latitudinal gradient in Europe. It has been shown that the structure of shoots changes with transition from the center to the northern or southern periphery of the species range. The reduction in the number of metameres at the range periphery is more distinct in orchids with multimetameric shoots, compared to those with oligometameric shoots. The plasticity of shoot structure observed along the geographic gradient is contingent on climatic factors and can be manifested regionally in cases of long-term temperature deviations. Other morphological parameters, such as shoot height and the sizes of leaves and flowers, can serve as indicators of ecological conditions in habitats.  相似文献   

7.
Leaf size, shape, and parameters of venation in Betula pendula and B. pubescens have been studied along a 1600-km latitudinal zonal transect in the Urals and Western Siberia. The results show that leaf size and venation density depend on the geographic location of population, with these parameters in the two species changing in opposite directions along the transect. In its northern part (forest tundra-southern taiga), B. pubescens shows a positive correlation of leaf area with long-term-average air temperature, while this correlation in B. pendula is negative. In the southern part, correlations of leaf size with long-term average precipitation in the two species are also opposite in sign. Parameters of leaf shape in both species depend mainly on weather conditions in the current year rather than on long-term average climatic parameters. The conclusion is drawn that B. pendula and B. pubescens have different mechanisms of structural adaptation of leaves to climate and weather conditions that are based on changes in leaf size and shape.  相似文献   

8.
Permafrost wetlands are one of the most sensitive plant communities in response to global warming. Global warming could induce natural plant communities to shift into cooler climate zones, or extirpate. To understand how plant communities in permafrost wetlands are affected by global warming, we examined the patterns of plant species diversity in the 24 permafrost wetlands in the Great Hing’an Mountains along a latitudinal gradient. This gradient was characterized by a northward decline in mean annual temperature (Δ = 3.5°C) and mean annual precipitation (Δ = 38.7 mm). Our results indicated that latitudinal patterns in species diversity existed in the permafrost wetlands. The numbers of family, genus and species, the Gleason index and Shannon-Wiener index for shrubs decreased linearly with decreasing latitude, but increased for herbaceous plants. The latitudinal patterns in species diversity had influenced strongly by temperature. Simple linear regression yielded about 2 decreases in shrub number and 9 increases in herbaceous species number with an increase of mean annual temperature by 1°C, with 0.33 decreases in shrub diversity and 0.29 increases in herbaceous species diversity. If temperature warms 3.7°C by 2100, herbaceous plants might increase in the permafrost wetlands, with species number increasing 48% or 6 times and species diversity increasing 40% or 2 times; and some shrub species might decrease and even disappear in part of the areas with lower latitude, with species number decreasing 50–100% and species diversity decreasing 69–100%. The permafrost wetlands in the Great Hing’an Mountains might continue degenerating and shift northward with global warming over the next century.  相似文献   

9.
The flora of Siberia includes 4500 species, 815 genera, and 123 families of angiosperms. The causes of the relationship between sexual forms and such ecological and biological features of plants as the life form, the mode of pollination, pericarp’s consistency, habitat type, zonal group, and the ecological group in relation to moistening were analyzed and discussed. For the first time, we demonstrated that gynomonoecy in the flora of Siberia was associated with a semiwoody growth form, pollination by wind, and propagation in zonal communities. It was revealed that gynodioecy in Siberia was associated with a semiwoody growth form, circumpolar or Eurasian distribution, and floodplain meadows. It was found that the ratio of dioecious and hermaphrodite plants in the ecological-biological complexes of species directly depends on the frequency of the abundance of species with endemic areas.  相似文献   

10.
Methods of geometric morphometrics have been used to compare the ranges and directions of geographic and technogenic forms of variation in the morphology of the mandible in Ural populations of pygmy wood mice (Sylvaemus uralensis Pall.) exposed to different types of pollutants (radionuclides, fluorides, and toxic petrochemical products). The range of variation in the mandible morphology consequent to chronic radiation exposure in the zone of the Eastern Ural Radioactive Trace is commensurate to the range of geographic variation of the species observed in the Middle and Southern Urals. Unspecific manifestations of variation have been revealed, which apparently result from exposure to technogenic pollutants of different origin. A probable contribution of technogenic variation to rapid morphogenetic rearrangements in populations is discussed.  相似文献   

11.
Impact of sea-surface warming upon the fish assemblages of the Portuguese coast was assessed under two scenarios, the A2 and the B2 scenarios (Special Report on Emission Scenarios), which when coupled with a regional circulation model HadRM3 predict 1 and 2°C of sea-surface warming until the year 2100. Species richness increased in the Portuguese coast. In both scenarios, there was a latitudinal gradient in the amount of lost and gained species, increasing from north to south. An anomaly in the latitudinal gradient of species richness was detected in the southernmost area, which presented the lowest species richness of all areas, in the A2 scenario, and appears to be particularly vulnerable to climate change. Very few species were totally eliminated from Portuguese waters. For the Portuguese coast as a whole, there were more new than lost species, in both scenarios. Most of the new species were commercially important species, in the majority subtropical in the north and tropical in the south, mainly demersal and reef-associated. Reef-associated species also increased in relative importance. A commercial opportunity for fisheries may arise from climate warming, since most of the new species were commercial species and not many commercial species were lost. An increasing gradient from north to south was detected in the colonization of new species of herbivores, planktivores, and omnivores, as well as lower mean trophic level, which might have consequences for the future of trophic webs.  相似文献   

12.
为了研究三峡水库周期性的水位调节对消落带植被群落特征的影响,选择重庆忠县至宜昌秭归段的消落带植被群落进行研究,运用重要值和多样性指数分析不同高程的植物种类组成、生活型分布特征及物种多样性。结果表明:(1)研究区域统计植物共32科70属73种,禾本科、菊科和豆科是3个优势科,单种、属现象明显;狗牙根、苍耳、鬼针草、苘麻、鳢肠、酸模叶蓼、莲子草是3个高程的共存种,其中,狗牙根和苍耳在3个高程均为优势物种。(2)研究区域共统计11种植物生活型,在消落带下部和中部,一年生草本植物占绝对优势;在消落带上部,多年生草本植物成为优势生活型,生活型类型多样化,蕨类、藤本、灌木以及乔木植物开始出现。(3)消落带植物群落的丰富度、多样性、均匀度指数均随海拔变化表现出显著差异,并且随海拔升高呈现上升趋势。由此可见,水位变化对植物群落结构和物种多样性产生很大影响,在低海拔区段,消落带物种组成简单化,耐水淹和繁衍能力强的植物成为优势物种;随着海拔上升,水淹胁迫减弱,出现更多适应水位变化的植物种类,使植物群落沿海拔变化形成不同的分布特征。这些研究结果对三峡库区消落带生态修复植物的筛选,以及物种多样性的提高具有参考价值。  相似文献   

13.
The ecotypic structure of two grayling species in Eurasia is considered. Based on original and published data, the development of ecological forms in water bodies of different kinds is analyzed. Parallelism in the emergence of highly similar forms in different sites of the ranges is demonstrated. Distinctive features of ecotypes and their internal structure are described. The causes and rate of establishment of forms with a short life cycle are discussed.  相似文献   

14.
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   

15.
Specific ecological features of ground beetles inhabiting city parks and suburban areas were studied in the large industrial city of Nizhnii Tagil (Sverdlovsk oblast). Carabid cenoses of city parks retained considerable species diversity but proved to be strongly dominated by a limited number of species. An analysis of their state before and after recreational impact revealed changes in the species composition of communities, the set of dominant species, the degrees of their dominance, and the ratio between classes of life forms. The results show that the stronger the recreational impact, the more significant the decrease in the species diversity of the carabid community.  相似文献   

16.
Discriminant analysis has been used to analyze the composition of phenotypic forms and geographic differentiation of spruce populations in northwestern Russia in comparison with those of “standard” Norway spruce and Siberian spruce populations. The absolute prevalence of trees with an intermediate Norway-Siberian spruce phenotype has been revealed in almost all populations, except for the northernmost ones. Spruce populations in northwestern Russia may be divided into at least three groups, with the southern group being closer to the Norway spruce, and all other groups, to the Siberian spruce.  相似文献   

17.
In the soils of bog ecosystems studied in Plesetskii raion of Arkhangelsk oblast, 169 species and infraspecific taxa of algae have been recorded. Their flora includes typical divisions of soil algae and is dominated by Chlorophyta, which is typical for the soil–climatic conditions of the taiga zone in general and bog ecosystems in particular. The phytocenotic organization of algal groups can serve as an indicator of bog trophicity, since a certain trophicity level is characterized by an individual combination of dominant species, life forms, morphotypes, and ecological groups of soil algae.  相似文献   

18.
Collections made in the course of long-term field studies on ecology of the northern mole vole Ellobius talpinus Pall. in the Ural Region and neighboring areas (more than 2000 individuals from 24 points of the species range) were used to analyze geographic variation in its coat color (color morphs). On the basis of long-term observations (1985–1999) on marked animals from a polymorphic population (Kurtamyshskii raion, Kurgan oblast), the life spans of males and females and the dependence of life span on population density and structure were estimated in animals of different color morphs. Each color morph of E. talpinus was shown to have specific features of the seasonal dynamics of age structure and migrations.  相似文献   

19.
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   

20.
Individual, intra- and interpopulation, ecological, and geographic variation has been studied in G. conopsea populations on limestones of the Timan Range. The results show that the response of plants to deterioration of growing conditions manifests itself in a decrease in the values of individual morphometric characters and the strength of correlations between them. In the northeast of European Russia, this species is represented by two forms, G. conopsea (L.) R.Br. s. str. and G. conopsea var. alpina Rchb. f. ex Beck (?), with the latter being regarded as an extreme form of its ecological variation.  相似文献   

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