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1.
Phenotypic variation in the widespread Siberian and Mongolian butterfly species Coenonympha amaryllis (Stoll, 1782), an indicator of undisturbed steppe communities, is analyzed. It is shown that its size variation is influenced by a complex of climatic factors, the most important of them being the average starting date of the frost-free period and average annual temperature in the region. Longitude-dependent variation in size is described by a “sawtooth curve” characteristic of species with changing voltinism.  相似文献   

2.
On the basis of abundant fossil and subfossil bone remains, the ecological and faunal role of the narrow-skulled vole in zonal rodent communities of northern Eurasia is analyzed over the period from the Late Pleistocene to the present time. Special attention is given to the correlated dynamics of relative abundance of Microtus gregalis and other rodent species in the course of transition from one zonal type to another and to specific features of this correlation in the southern, middle, and northern parts of the species range. It is shown that distinctive dimensional and morphotypic features of the two currently existing subspecies, Microtus gregalis major Ogn. and M. g. gregalis Pall., are the product of concordant development of the species and environmental conditions in the past 3000–4000 years (transition from the Holocene optimum to the present-day climate and state of the natural environment). Published in Russian in Ekologiya, 2007, Vol. 38, No. 2, pp. 117–123. The article was translated by the authors.  相似文献   

3.
4.
Experimental studies of interactions between two amphipod species (Gmelinoides fasciatus and Gammarus lacustris) showed that predation is the basic mechanism accounting for their mutual exclusion in nature. Mortality from predation among similar-sized specimens of both species at an equal abundance ratio was similar (24–25% in G. lacustris and 27–30% in G. fasciatus). The displacement of G. lacustris by G. fasciatus was observed when the latter was dominant. Adult G. fasciatus and G. lacustris successfully preyed on juveniles of their competitors and did not differ significantly in daily food consumption as a percentage of body weight: 6–24% at a fresh body weight of 18–24 mg in both species. The potential for rapid population growth under new conditions contributed to the success of the invasive Baikal species G. fasciatus in displacing G. lacustris from many water bodies of Russia.  相似文献   

5.
The allozyme analysis of six local populations of Pinus mugo Turra and six populations of P. sylvestris L. in the Ukrainian Carpathians, Swiss Alps, and Schwarzwald has shown a higher polymorphism and greater interpopulation differentiation of the Carpathian group of P. mugo populations compared to the Alpine group (Nei’s genetic distance DN 78 at the level of geographic population group is −0.023). A genetic differentiation of DN 78 = 0.049 between these populations, which are isolated by a distance of more than 1000 km, has been found. This confirms the existence of the subspecies P. mugo ssp. mugo and P. mugo ssp. uncinata in the Carpathians and Alps, respectively. The hypothesis is put forward that the former subspecies has been formed in the Balkans and the latter, in the Pyreneans. It has been demonstrated that regional populations and geographic groups of P. sylvestris are less differentiated than those of P. mugo.  相似文献   

6.
The linear increment of Sphagnum fuscum and S. magellanicum in ombrotrophic mires of Western Siberia has been measured during two years over a transect about 2500 km long extending from forest–steppe to forest–tundra. Along the latitudinal gradient, the increment of both species has proved to be correlated with annual average air temperature and, in S. magellanicum, also with annual precipitation. The determinants of their growth differ between the southern, central, and northern parts of the study region. At the regional level, the annual and summer precipitation plays a more important role than the average air temperature. The increment of S. fuscum in the southern part is positively correlated with the amount of precipitation and negatively correlated with summer temperature, whereas the situation in the central part is inverse. In S. magellanicum, the linear increment is directly dependent on the annual average temperature and annual and summer precipitation in the south and on the annual and summer precipitation in the north of Western Siberia. The dynamics of linear growth of both species in bog pine forests during the growing season are similar: its rate is the highest in June, when the linear increment of S. fuscum and S. magellanicum amounts to 60 and 85% of the annual total, respectively.  相似文献   

7.
To estimate the capacity of the White Sea littoral mollusk Hydrobia ulvae (Pennant, 1777) for adaptation to changes in ambient salinity, the range of its tolerance to increased and decreased salinity was determined experimentally. The results were used to plot the salinity tolerance polygon. On this basis, it was estimated that H. ulvae can live in a salinity range of 6–85‰.  相似文献   

8.
We compared differences in plant species diversity between conifer (Pinus tabulaeformis) plantations and natural secondary forests in the middle of the Loess plateau. The goal of the study was to examine the differences in the effect of stand development on species diversity and in species responses to changes between forest types and between forest layers. To clarify the effects of differences in forest management, we emphasized the functional types of plant species occurring in each forest type. The result as follow: (1) The H′ and S of tree layer were significantly lower in natural conifer forest than old conifer and secondary forest, but were not different compared with mid aged conifer forest. The H′ and S of shrub layer were significantly lower in mid aged conifer forest compared with other forest types. The H′ of herb layer showed no significant differences in the four forest types. The evenness index (J′) of tree layer of mid aged conifer forest was lower than other forest communities and its J′ of shrub layer was highest although its richness of shrub layer was lower than in the other forest types. (2) The analysis of β diversity index also indicated large differences between conifer plantations and natural forests. Although the tree layer species were similar in old plantation and natural conifer forests, they differed greatly between the natural conifer and secondary forests. The natural conifer and secondary forest species composition in shrub layer differed significantly from those in plantation and secondary plots. Tree species were significantly less common in plantations than in abandoned coppice forests. Species composition in the herb layer of different forest types was similar. (3) The management of P. tabulaeformis plantations alters plant species composition considerably; the number of sub tall-tree species is increased in old aged conifer forest, especially species dispersed by animals. Plantation management appears to affect ecological processes through seed dispersal. From the perspective of management, the change in the structure and composition of the canopy in plantations could affect the behavior of dispersers and regeneration.  相似文献   

9.
A comparative analysis of spatial population structure in the northern red-backed vole (Clethrionomys rutilus Pall.) and large-toothed red-backed vole (Cl. rufocanus Sund.) has been performed in the middle taiga zone of the Middle Irtysh region (Omsk oblast). Populations of these species are represented by sets of territorial groups whose numbers and spatial distribution change from year to year depending on the ratio of these species in a biotope and their population density. There is no significant interspecific competition between cohabitant Cl. rutilus and Cl. rufocanus. In particular, this follows from the fact that the population density and distribution pattern of one species are independent of those of the other species. It has been found that the size of home ranges in Cl. rutilus inversely depends on its population density, with that in Cl. rufocanus remaining approximately the same at different population densities, and that the structure of the resident part of the population in both species changes during the season, as voles from neighboring habitats or dispersing voles settle in the study area.  相似文献   

10.
Demographic structure and its seasonal dynamics have been studied in colonies of narrow-skulled voles (Lasiopodomys gregalis Pall.) in Northern Kulunda. Three types of colonies have been distinguished: (I) true colonies (large, complex families), (II) simple families (nuclear or incomplete), and (III) all-male colonies. Changes in their sex, age, and functional composition (based on animal migration activity) during the breeding season have been analyzed.  相似文献   

11.
Environmental factors like temperature and soil humidity are recognized as influencing factors on photosynthetic response and organic productivity, distribution and biochemical characteristics of plants. Here we present measurements of gas exchange parameters, water-use efficiency (WUE) and nitrogen-use efficiency (NUE) of field-grown invasive species Ambrosia artemisiifolia L., Ambrosia trifida L. and Iva xanthifolia Nutt., in order to define their potentials as colonizers. Biogenic volatile organic compounds (BVOC) in leaves and flowers depending on soil humidity were also investigated.  相似文献   

12.
Effects of copper ions and copper oxide nanoparticles on lipid peroxidation rate, activities of anti-oxidant enzymes (superoxide dismutase, catalase, and peroxidase), and photosynthesis have been studied in experiments with Elodea densa Planch. The results show that nanoparticles are more actively accumulated by plants. Both copper ions and nanoparticles activate lipid peroxidation (to 120 and 180% of the control level, respectively). Catalase and superoxide dismutase activities in plants treated with nanoparticles increase by a factor of 1.5–2.0. Copper ions suppress photosynthesis at a concentration of 0.5 mg/l, whereas nanoparticles produce such an effect only at 1.0 mg/l. The observed effects of different forms of copper on E. densa are discussed in a comparative aspect.  相似文献   

13.
Variations in breeding success of the Whiskered Terns (Chlidonias hybrida) were studied in two wetlands; Anzali (2005 and 2008) and Zarivar (2007–2008) in north and west Iran. Nesting success was modeled and compared using information-theoretic approach implemented in program Mark in order to assess effects of colony locations, years and nest initiation dates on the probability of daily nest survival. Clutch size did not vary between colonies and years. Breeding success varied between colonies (Zarivar > Anzali), and years only in Anzali (2005 > 2008). Overall daily nest survival was 0.977. (95% LCI 0.973, UCI 0.981), equivalent to a Mayfield nest survival of 0.317. (95% LCI 0.255, UCI 0.387). Egg-laying periods and colony site were important covariates affecting the daily survival rates (Σω i = 0.86 and Σω i = 0.83, respectively), while, the support for the effect of year was less (Σω i = 0.41). We concluded that Lake Zarivar provides a more favorable nesting location for Whiskered Terns probably because of little changes in rainfall and water depth during the breeding seasons which influence breeding performance.  相似文献   

14.
To better understand how Batrachupems tibetanus responds to different temperature regimes in the blood parameters and to estimate the change in plasma cortisol level in this species exposed to different temperatures, the animals were stochastically divided into three groups and exposed respectively to 4.6°C, 14.6°C and 19.6°C for 12 days. The concentrations of glucose, total protein, albumin, triacylglycerol, Ca2+, K+, Na+, Cl, and plasma cortisol level were measured respectively. There was no significant difference between the plasma cortisol level of the control group and the experiment groups. Glucose level at 4.6°C and 19.6°C was significantly lower than glucose level at 14.6°C. The plasma triacylglycerol level was significantly influenced by acclimation temperature. The concentration of total protein, albumin, globulin and the ratio between albumin and globulin were not significantly influenced by temperature when compared with control group. There was no significant change in concentration of Ca2+ at different temperatures. The concentration of K+ was significantly influenced by temperature. Plasma K+ level significantly increased at 19.6°C. The plasma Na+ level and Cl were significantly influenced by temperature. Na+: Cl ratio was significantly influenced by temperature. Therefore, glucose, triacylglycerol, Na+ and Cl levels could be considered as indicators of thermal stress in B. tibetanus; plasma cortisol, albumin, globulin levels, and albumin/globulin ratio are not influenced by temperature.  相似文献   

15.
Eight strains of bacteria capable of degrading polycyclic aromatic hydrocarbons have been isolated from soils and bottom sediments sampled in the region of Verkhnekamskoe potash deposit (Berezniki, Perm krai) and classified with the genus Arthrobacter on the basis of phylogenetic analysis (16S rRNA genes) and morphological and chemotaxonomic characters. According to the results of 16S rDNA sequence alignment, strains B905, SMB11, SMB145, SF27, and DF14 show the highest sequence homology to the type strain of A. crystallopoietes (99.7%), and strain SN17, to the type strain of A. arilaitensis (99.8%). The isolated strains are capable of growing on naphthalene and phenanthrene (as the sole sources of carbon and energy) in the presence of 60 mg/l NaCl. Their cells contain large plasmids ranging in size from 85 to 130 kb. Plasmid elimination from Arthrobacter sp. SF27 has proved to result in the loss of capacity for growing on naphthalene and phenanthrene, suggesting a plasmid localization of genes responsible for degradation of these compounds.  相似文献   

16.
The capacity of species for expansion and colonization of new habitats is a key condition for the maintenance of their populations. In this study, specific features of the reproductive potential have been analyzed in Lobaria pulmonaria populations growing under contrasting climatic conditions. Certain ecological determinants governing the development of this lichen species have been revealed.  相似文献   

17.
We tested separately the effect of two taxonomically related rotifers (B. patulus and B. macracanthus) on the population dynamics of another species (A. fissa) at low (0.5 ×10 6) and high food levels (1.5 × 106 cells/ml of Chlorella vulgaris) using different inoculation densities (0–100%). We also quantified the impact of A. fissa on the two brachionid species. Regardless of the presence of the competing species, an increase in the availability of food led to increase in the abundances of the three rotifers. The population growth of B. patulus, B. macracanthus, or A. fissa was affected negatively when cultured together with another species. An increase in the initial density of any one of the competing species became advantageous to maintain a certain population size. At a low algal food level, B. patulus was able to suppress A. fissa more strongly than B. macracanthus. On the other hand, at a high food level, B. macracanthus suppressed the population of A. fissa more strongly than B. patulus. Peak population densities for A. fissa varied from about 150 to 1000 ind./ml, depending on food density and the presence of competitors. The rate of population increase (r) of A. fissa, B. patulus, and B. macracanthus increased with an increase in food availability but decreased with increasing initial density of the competitor. Both Brachionus spp. experienced negative growth rates in the presence of A. fissa, especially at a high initial density of the latter. Published in Russian in Ekologiya, 2007, Vol. 38, No. 5, pp. 381–390. The article was submitted by the authors in English.  相似文献   

18.
Methods of geometric morphometrics have been used to estimate the influence ratio of nonselective elimination and drought factors on variation in the shape and size of the mandible in the population of bank vole (Clethrionomys glareolus Schreb.) in the southern taiga subzone. Nonselective elimination of rodent populations for medical and sanitary purposes was carried out in a felling site located in a focus of hemorrhagic fever, in the spring of a climatically normal year and of a dry year. The summer samples of mature young of the year from control bank vole colonies and impact colonies (i.e., recovered after deratization) in adjacent years have been compared. The results show that drought, nonselective elimination, and the interaction of these factors have significant effects on the size and shape of the mandible. Changes in its shape under drought conditions are largely due to allometry. Morphogenetic effects of nonselective elimination are highly repeatable between climatically different years. A significantly higher level of within-group morphological disparity (MNND) of the undisturbed control cenopopulation in a dry year has been revealed, which indirectly indicates a stronger destabilization of morphogenesis upon exposure to the autecological factor. Every ecological factor contributes to the development of specific configurations of the mandible; i.e., it induces certain changes in morphogenesis in response to aut- and synecological effects and their combination.  相似文献   

19.
The structure of the long-eared owl (Asio otus L.) settlements in anthropogenic landscapes has been studied in the Zhuravlinaya Rodina protected territory in the northern Moscow region in 2001–2005. The possible factors that cause the formation of such settlements have been analyzed. The differences in the breeding success between owls nesting near and away from human settlements have been estimated. Aggregated nesting of owls is assumed to be mainly related to a lower predator pressure in the vicinity of human dwellings in the incubation period. Aggregated nesting is regarded as an expression of synanthropization of the species.  相似文献   

20.
The physiological and biochemical characteristics of seedlings of Descurainia sophia (Fisch.) and Lepidium apetalum Wild. have been used as examples to demonstrate that long-term exposure of plant populations to environmental stress factors causes adaptive changes in antioxidant and genomic systems that may considerably affect the radioresistance of seed progeny. The resistance to additional acute irradiation of seed progeny of wild plants adapted to different environmental conditions has been found to be determined not only by the combination of antioxidant and DNA-repair protection systems and the vulnerability of the functioning genome, but also by their variability. The data on the relationship of the radioresistance of wild plant populations with physiological and biochemical characteristics and their variability may be used for expert environmental assessment of the state of the biota and prediction of its viability under exposure to abiotic environmental factors.  相似文献   

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