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1.
The results of phenetic studies on chum salmon populations from the rivers flowing into Taui and Yama bays, Sea of Okhotsk, are discussed. The heterogeneity of samples with respect to the frequency of a certain phene in females is not necessarily revealed when this frequency is analyzed in males. Statistically significant heterogeneity with respect to phene frequencies is observed in all chum salmon populations, whether the corresponding data are analyzed by years or throughout the observation period. This population heterogeneity is accounted for by specific phenetic features of each chum salmon population, although in different years it manifests itself in the frequencies of different phenes. The phenes distinguished on the head of fish contribute most significantly to interpopulation differences.  相似文献   

2.
The phenetic structure of Dreissena polymorpha populations in different water bodies is considered. The phenotypes of shell pattern and sculpture are identified and described using a scheme based on elementary characters, or pattern elements. It is shown that the frequencies of phenes in mollusks from different biotopes of the cooling system of two thermal power plants differ significantly. The data on species phenogeography are reviewed.  相似文献   

3.
The vertical distribution of 137Cs activity in peat soil profiles and 137Cs activity concentration in plants of various species was studied in samples collected at two sites on a raised bog in central Sweden. One site (open bog) was in an area with no trees and only a few sparsely growing plant species, while the other (low pine) was less than 100 m from the open bog site and had slowly growing Scots pine, a field layer dominated by some ericaceous plants and ground well-covered by plants. The plant samples were collected in 2004–2007 and were compared with samples collected in 1989 from the same open bog and low pine sites. Ground deposition of 137Cs in 2005 was similar at both sites, 23?000 Bq m−2. In the open bog peat profile it seems to be an upward transport of caesium since a clear peak of 137Cs activity was found in the uppermost 1–4 cm of Sphagnum layers, whereas at the low pine site 137Cs was mainly found in deeper (10–12 cm) layers. The migration rate was 0.57 cm yr−1 at the open bog site and the migration centre of 137Cs was at a depth of 10.7, while the rate at the low pine site was 0.78 cm yr−1 and the migration centre was at 14.9 cm. Heather (Calluna vulgaris) was the plant species with the highest 137Cs activity concentrations at both sites, 43.5 k Bq−1 DM in 1989 decreasing to 20.4 in 2004–2007 on open bog and 22.3 k Bq kg−1 DM in 1989 decreasing to 11.2 k Bq−1 DM by the period 2004–2007 on the low pine site. 137Cs transfer factors in plants varied between 0.88 and 1.35 on the open bog and between 0.48 and 0.69 m2 kg−1 DM at the low pine site.  相似文献   

4.
Few studies exist on phenotypic composition of the sable populations in the Russian Far East, China and Japan. We present new data on the morphological diversification of sable for 20 mainland and island populations in an effort to document existing variability and produce baseline data that would be useful in constructing phylogenies for this species. Сlinal variability of skull size, cranial phene, foramen in fossa condyloidei inferior (FFCI), and fur coloration is revealed. One district, Central Sikhote-Alin, is characterized by sables with the minimum cranial size and the maximum phene expression. The area between the Uda River and Goryun and Amgun rivers is inhabited by sables of the darkest fur coloration. Moving out from those areas in all directions we were detected a trend of increasing skull size, reduction of cranial phene, and decreasing color intensity of fur. The skull size of sable is consistent with Bergmann’s rule. Special attention paid to the particular morphological properties of insular populations in specific climatic conditions and under isolation from the continent. They are characterized by minimal expression phene FFCI (Bolshoi Shantar, Iturup, and Hokkaido islands) and larger skull size, especially in sable of Kamchatka Peninsula. It is hypothesized that the area of the lower Amur Basin was a source of sable postglacial dispersal on the Eurasian Continent.  相似文献   

5.
Monitoring of A. uralensis populations in Kamenskii raion, Sverdlovsk oblast, in 1992–2002 and in Kaslinskii raion, Chelyabinsk oblast, in 2000–2001 revealed an increase in the proportion and diversity of minor morphogenetic aberrations and abnormalities in the structure of the cranium along the axis of the Eastern Ural Radioactive Trace (EURT). The samples from the southern and northern parts of the EURT (contaminated with 90Sr to 500 and 4 Ci/km2, respectively) were characterized by directed deviations from the control with respect to the frequencies of phenes of nonmetric cranial traits and an increase in the level of their fluctuating asymmetry in young females, which is indicative of epigenetic rearrangements in populations living in a radioactive environment.  相似文献   

6.
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   

7.
Generalizations are made on the basis of results obtained in the course of long-term, stationary quantitative studies on phenogenetic divergence of P. sylvestris populations growing in an upland bog and the adjacent dry land area in the pre-forest-steppe zone of Western Siberia. Contrasting differences between the two edaphoecotopes and almost complete phenological reproductive isolation of populations from year to year are demonstrated. It has been found that root morphogenesis in the F 1 progeny of pine from the bog population grown under uniform ecological conditions in the dry land area is characterized by elimination of the vertical phenotype, with the alternative lateral phenotype type being dominant in 7- to 22-year seedlings. Significant allozyme differentiation and distinct chorological boundary between the dry-land and bog populations have been revealed. The hypothesis of their genetic divergence in the Holocene is proposed, with this phenomenon being explained by the cumulative effect of disruptive selection and strict reproductive isolation in two contrasting environments.  相似文献   

8.
An evolutionary-ecological analysis of homologous variations in cranial morphological structures (phenes) has been performed at the level of populations and subspecies exposed to technogenic, climatic, and landscape-geographic changes in the environment, as well as with ecological series of 46 species and infraspecific forms differing in ecological specialization within the family Cricetidae. On this basis, consistent manifestations of phenogenetic variation have been revealed. Species with the same ecological specialization show parallel directional changes in the frequencies of homologous phenes and their individual combinations. These changes apparently have adaptive significance and result from rearrangements in the ancestral epigenetic system. It is shown that similar ecological requirements imposed by the environment historically lead to unidirectional transformations of homologous morphological structures in different species, which may account for high incidence of homoplasy as well as for the parallel and, in part, directional evolution of closely related taxa with similar ecological specialization.  相似文献   

9.
Chinese pine, Pinus tabulaeformis Carr., a species that ranges broadly across northeastern to southwestern China, plays a vital role in the maintenance of the structure and function of these ecosystems. In this study, we examined the genetic diversity of five widespread populations in Shanxi Plateau, the distribution center of Chinese pine, using 15 random amplified polymorphic DNA (RAPD) primers and five inter simple sequence repeat (ISSR) primers in 140 individual tree samples. Similar genetic differentiation results were obtained from the data of RAPD and ISSR. Based on the two sets of data, Nei’s genetic diversity was 0.2842 and 0.3078 and Shannon’s indices of diversity were 0.4332 and 0.4468. Genetic diversity at the species level was found high relative to that for other genera of Pinaceae. The greatest diversity was observed in the Lingkong Mountain population (0.3860), while the lowest was recorded in the Luya Mountain population (0.3352), most likely as a result of natural adaptation and anthropogenic perturbation. The relative magnitude of differentiation among populations (G ST) was 0.1491 and 0.1356, respectively, implying that most genetic variation was within the populations (∼0.8509), rather than among populations. Published in Russian in Ekologiya, 2008, No. 1, pp. 36–42. The article was translated by the authors.  相似文献   

10.
Cytogenetic variation was analyzed in daughter populations of Scotch pine from the Voronezh Forestry. The dependence of the variation on the method of seed collection (the commercial method; the population method, when seeds from a group of phenotypically normal trees in the center of the forest are collected; or the individual method, when seeds from plus trees are collected) and on the ecological situation at the sampling site (ecologically safe conditions or chemical or physical pollution) was studied. The parameters of the mitotic rate and mitotic pathology were estimated at 7–9% and up to 5%, respectively. These parameters may be considered as normal when estimating the quality of seed progeny in pine and when pine is used as a test object in cytogenetic monitoring. The limits of variation and the spectra of cytogenetic characteristics allowing the pine populations to maintain their homeostasis were also determined.  相似文献   

11.
The morphology and development are described for Siberian stone pine (Pinus sibiricaDu Tour) growing at the timberline in the Western Sayan Mountains. Throughout ontogeny, these plants have a short stem trailing in an approximately horizontal direction. Maximal longevity and viability are characteristic of basal branches, which are able to root and produce vegetative generations. This allows these plants to be classified with the procumbent tree life form, in which the clones of most adaptive genotypes not only survive under extreme environmental conditions, but can also reproduce vegetatively.  相似文献   

12.
Forest structure and regeneration were studied along the altitudinal gradient in the Binsar Wildlife Sanctuary of Uttarakhand Himalaya in India. Stratified random sampling of tree species was done by placing minimum 15 quadrats of 10 × 10 m at each aspect and altitude. The results reveal that along the altitudinal gradient there were three types of forest communities in the Sanctuary viz., chir pine (Pinus roxburghii), oakchir pine (Quercus leucotrichophora and Pinus roxburghii) and oak (Quercus floribunda and Quercus leucotrichophora). Rhododendron arboreum, Cornus macrophylla and Lyonia ovalifolia were main associates of these forest communities. The oak forests had larger shrub population as compared to chir pine. Myrsine africana was the most dominant shrub across the altitudinal gradient, whereas few shrub species were restricted to a certain altitudinal range. The regeneration of chir pine was best at lower altitude on south and east aspects, which indicates that it mostly regenerates on warm and dry slopes. In general, the regeneration potential in most of the tree species declines with the altitude. The density of saplings and seedlings also represented the dominant species at each altitudinal range, which indicates the cyclic regeneration of forests in the Sanctuary area.  相似文献   

13.
The diet structure of Asian badgers (Meles leucurus Hodgson, 1847) on Bol’shoi Chukhtinskii Island (Samarovskii Chugas Nature Park, Khanty-Mansi Autonomous Area) was studied by means of coprological analysis. Ten diet components were identified, including Siberian stone pine seeds (pine nuts), berries, earthworms, larval and adult insects, fishes, amphibians, reptiles, and mammals. The proportion of pine nuts was especially large. Seasonal fluctuations in the occurrence frequency and abundance of different foods were insignificant, but some of them were found to markedly vary between years.  相似文献   

14.
A population of the cranberry fritillary (Boloria aquilonaris) was studied in a forest bog in Southern Karelia. The butterflies in this habitat were distributed unevenly, forming large aggregations in the driest sites overgrown by Comarum palustre. All areas inhabited by the population were interconnected by fluxes of butterflies. The maximum recorded distance covered by a an individual was 1.5 km. The B. aquilonaris residence area was delimited on the basis of an exponential model. Specific features of the spatial organization of B. aquilonaris populations in spatially homogeneous and fragmented environments are discussed.  相似文献   

15.
A comparative cytogenetic study has been performed in four populations of two pine species, Pinus cretaceae Kalen. and P. sylvestris L., growing on sandy and chalky substrates in Voronezh and Belgorod oblasts. Significant differences in the parameters of mitotic and nucleolar activities, as well as the rate and spectrum of mitotic pathology, between populations of P. cretaceae and P. sylvestris and between populations of P. cretaceae growing under different conditions have been found. Populations of P. sylvestris growing on sandy and chalky substrates differ from each other in nucleolar activity. These differences may be adaptive and reflect the characteristic metabolic patterns and biological plasticity of pines growing under specific conditions.  相似文献   

16.
Pinus roxburghii (chir-pine) and Quercus leucothchophora (banj-oak) are dominant forests of mountainous part of the Uttarakhand Himalaya. The continued anthropogenic disturbance is opening the canopy, forming canopy gaps and as a result forest fragments are developing. Thus, the present study aims to analyze variations in species richness and vegetational parameters in relation to canopy gaps in forests. Total species richness was greater in open canopied forest compared to moderate and close canopied forests. In comparison between oak and pine forest, it was greater in oak forest while the proportion of common species was low between oak—pine forests. Mean species richness did not significantly vary from one canopy gap to another as well as in oak and pine dominated forest. This indicated that dominant forest types played an important role to form the community structure. The shrubs richness were greater in closed canopy and between the forests it was greater in pine forest. Tree and shrub density was low in open canopy while herb density was high in moderate canopy. Thus, this study indicated that the dominant canopy species play an important role in deciding the community structures especially the distribution of under canopy species. These parameters should be considered for conservation and maintenance of plant biodiversity of a region.  相似文献   

17.
A study of allozyme spectra has been performed in dandelion cenopopulations growing for a long time under conditions of chemical pollution (the zone of the Nizhnii Tagil Metallurgical Plant, NTMP) or radioactive contamination (the zone of the Eastern Ural Radioactive Trace, EURT). Cenopopulations from the NTMP and EURT zones and from the background area differ significantly in the qualitative and quantitative composition of allozyme phenes. An analysis of clonal diversity has shown that all cenopopulations are phenogenetically unique. The genesis of each cenopopulation proceeded in a specific way: they had different sets of progenitor plants, whose descendants varied genetically in the course of their reproduction and more or less successful colonization of habitats, undergoing selection under the impact of natural environmental factors and technogenic stress. An increased variability of enzyme systems, compared to the sample from the background area, and, as a consequence, reduced clonal diversity may be regarded as a trait common to populations exposed to chemical or radiation stress.  相似文献   

18.
Polymorphism of 11 enzyme systems has been studied in dwarf Scots pine trees occurring on sand dunes and crags in two populations of southern Central Siberia. High genotypic variability of dwarfs and their similarity to normal trees in basic indices of genetic diversity have been revealed. Both populations, including normal and dwarf trees, are in the Hardy-Weinberg equilibrium. The sample of dwarf trees has proved to differ from the “norm” in showing an age-related trend toward decreased heterozygosity. The observed linkage disequilibrium at some pairs of loci can be explained by unequal contributions of trees to population reproduction or by a recent bottleneck event. The populations studied are similar to other Scots pine populations from the Asian part of the species range. Increased frequencies of some rare alleles in the populations from Tuva provide evidence for the probable presence of a glacial refugium for pine in this region.  相似文献   

19.
The structure of Siberian stone pine (Pinus sibirica Du Tour.) and Siberian larch (Larix sibirica Ledeb.) stands and specific features of their formation have been studies in the forest-tundra ecotone on the North Chuya Ridge (2235–2475 m a.s.l.). Changes in the structure of these stands along the transition from the upper boundary of closed forests to the high-mountain tundra have proved to have an ambiguous pattern. Both tree species form mixed clusters of similar-aged trees in the lower part of the ecotone but grow singly, in scatters, in its upper part. The formation of conifer stands (tree clusters) in the lower part of the ecotone, on the slopes of the Aktru River valley, began during climate warming in the second half of the 19th century. The expansion of confers to its upper part took place markedly later, in the early 20th century (Siberian larch) or even in the 1930s (Siberian stone pine).  相似文献   

20.
The Holocene evolution of vegetation in the high-plain territory of the northwestern Volga Upland has been shown to have certain specific features. Based on analysis of spore–pollen assemblages from peat deposits, the onset of bog formation has been dated to the late Boreal period (about 8500 yr BP); the pine–birch phase in the development of forests, to the early Atlantic period (8000?6000 yr BP); the appearance and peak development of the zonal broadleaf species complex, to the late Atlantic period (6000?4500 yr BP); and early anthropogenic changes in the vegetation, to about 3000 yr BP.  相似文献   

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