共查询到20条相似文献,搜索用时 15 毫秒
1.
N. A. Berezina 《Russian Journal of Ecology》2009,40(2):81-85
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
2.
Life history traits of gypsy moth larvae markedly decrease under the effect of host plant insect resistance, but no significant changes occur in immunity parameters such as hemolymph phagocytic activity and lysozyme-like activity of hemolymph plasma and midgut tissue; moreover, alkaline protease activity in the midgut contents becomes higher. The actual sensitivity of the larvae to Bacillus thuringiensis remains unchanged. 相似文献
3.
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
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S. N. Sannikov I. V. Petrova F. Schweingruber E. V. Egorov T. V. Parpan 《Russian Journal of Ecology》2011,42(4):270-276
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
7.
E. A. Basargin 《Russian Journal of Ecology》2007,38(5):323-326
A discrete approach to the study of ontogeny has made it possible to reveal a high degree of age heterogeneity in P. bifurca cenopopulations. The basal ontogenetic spectrum of cenopopulations has been determined. The index of regeneration is higher in cenopopulations of the young type and decreases in cenopopulations of the old type, whereas the situation with the index of senescence is inverse. The density of cenopopulations depends mainly on parameters of the substrate (density, composition, and moisture), its slope, and the intensity of plant vegetative reproduction and spread. 相似文献
8.
M. A. Potapov I. V. Zadubrovskaya P. A. Zadubrovskii O. F. Potapova V. I. Evsikov 《Russian Journal of Ecology》2012,43(1):40-44
A comparative analysis of reproductive behavior has been performed in the steppe lemming (Lagurus lagurus) and narrow-skulled vole (Microtus gregalis). The results show that the species are similar in certain behavioral features indicative of the stability of mating pairs.
However, in the narrow-skulled vole, unlike in the steppe lemming, mature males in olfactory tests show preference for receptive
sibling females versus non-kin females. Probably, it is the absence of the incest taboo that allows the involvement of young
of the year in reproduction within growing family groups and accounts for “coloniality” of the species. 相似文献
9.
Ai-Ping Wu Ya-Xuan Zhao Fei-Fei He Yan-Hong Wang Wen Zhong 《Russian Journal of Ecology》2017,48(3):226-232
Kudzu (Pueraria lobata) is an aggressive invasive species and has brought great loss world-widely. Though it is originated in China, it has not been considered as a weed in China. While more and more articles report its destructive effects on the native community throughout the whole country. We conducted an experiment to validate whether kudzu could endanger its native ecosystem and wanted to find the reason of its fast spreading from 2008 to 2010. Concentrations of nitrogen and phosphorus, water content, irradiance, pH, species number and aboveground biomass in the three sub-communities (Kudzu, Mixed and NonKudzu) were analyzed. Meanwhile, light irradiance and coverage of kudzu at 0, 25, 50, 100, 500, 1000 and 2000 m distance from the road surface verge were also measured. The results showed that kudzu evidently lowed the species biodiversity and obviously changed the water, light and nutrient cycles in its expanding area. Kudzu’s rapid expansion is mainly because it can get full available space and light for growth by reason of anthropogenic disturbances. Our results indicated that Kudzu was a potential weed in China if great land changes from human activities are continuing. 相似文献
10.
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
11.
Shailendra Kumar Vinayak Ram Tripathi Surendra Vikram Bipul Kumar Satyendra Kumar Garg 《Environment, Development and Sustainability》2018,20(6):2447-2461
The water sources in developing countries are usually contaminated with the members of enterobacteriaceae leading to gastrointestinal infections. There has been an increasing consumption of antibiotics during last decade in India. The development of multiple antibiotic resistance and heavy metal tolerance among waterborne bacteria has been coexisting traits. Keeping above features in view, 51 waterborne isolates of Escherichia coli O157:H7 have been characterized in the present study. The disk diffusion test for antibiotic sensitivity assay revealed that all the isolates were resistant to at least one or more antibiotics. Cephalosporins were least effective, while fluoroquinolones and aminoglycosides were most effective antibiotics. The isolates shared resistance pattern similarities regardless of their sources. The isolates were subjected to test maximum tolerance concentration of heavy metals such as arsenic, lead, chromium and mercury. About 98% isolates tolerated arsenic at 250 μg ml?1 or various above concentrations. Mercury >25 μg ml?1 was not tolerated by more than 90% isolates. In dug well, a commonly used water source in rural India, the isolates exhibited multiple antibiotic resistance index of 0.68 indicating it as high risk contaminating source. PCR–RFLP of 16S rDNA distinguished isolates into four groups with the smallest group represented by 3 isolates. Three isolates belonged to different sources but shared all the features of biochemical, serological, multiple antibiotic resistance and heavy metal tolerance test. 16S rDNA sequence analysis showed that the three selected isolates were closely related to each other. Based on the microbial and molecular findings, the study recommends to follow social cognitive theory to alter the behavior of the local communities for sustainable use of water resources. 相似文献
12.
G. V. Matyashenko V. N. Shmakov Yu. M. Konstantinov G. A. Belogolova 《Russian Journal of Ecology》2005,36(6):396-399
The accumulation of fluorine in the trunk wood and branches of Larix gmelinii growing on soils with a naturally increased fluoride content and of L. sibirica growing in a zone affected by atmospheric emissions from an aluminum plant has been studied. Based on results of in vivo and in vitro experiments, it is concluded that larch trees manifest individual differences in their response to fluorine. 相似文献
13.
The rates of lipid peroxidation (LPO) have been studied in Taraxacum officinale Wigg. (Asteraceae) and Vicia cracca L. (Fabaceae) from urban ecosystems with different levels of soil pollution with heavy metals (HMs), including Pb, Zn, Cu, and Cr. The former species responds to the increased HM contents by intensification of LPO processes, with their parameters correlating with the concentrations of Pb, Zn, and Cu in the soil. In the latter species from the same biotopes, conversely, LPO homeostasis remains actually undisturbed. 相似文献
14.
Body size-dependent mating pattern is thought to a consequence of the sexual selection on phenotypic characters. In the view, we investigated the mating patterns in Bufo andrewsi from three populations at different latitude in three Nature Reserves (i.e. Wanglang, Yele and Fengtongzhai) in China from early- March to late-May 2013 and 2014. The results showed that average body size did not differ significantly between amplectant and non-amplectant males within each population. We found a significantly positive relationship in body size between the amplectant males and amplectant females in Wanglang population, but not in Qiqiao and Yele populations. The strength of size-dependent mating was not correlated with the malebiased operational sex ratios (OSRs), suggesting that intensity of male-male competition at nights do not result in variation in size-dependent mating patterns in B. andrewsi among populations. 相似文献
15.
Variation and intraspecific differentiation of Oxytropis chankaensis Jurtz. (Fabaceae), a plant endemic to the Russian Far East, have been studied by analyzing a complex of morphological characters. A high level of morphological variation has been revealed, and the most variable populations growing in the Khankaiskii Nature Reserve have been identified. Populations growing in the zone of anthropogenic impact are characterized by low values and reduced variability of test characters. Distinct morphological differentiation of O. chankaensis populations has been observed. 相似文献
16.
E. G. Plotnikova O. V. Yastrebova L. N. Anan’ina L. V. Dorofeeva V. Ya. Lysanskaya V. A. Demakov 《Russian Journal of Ecology》2011,42(6):502-509
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
17.
The decline of spruce stands in Belarus has been analyzed in relation to the dynamics of climatic variables. The results show that this process is correlated with the amount of precipitation, moisture deficit, index of aridity, relative air humidity, and evapotranspiration. Frosts at the onset of the growing season enhance tree die-off, while increase in cloud cover has a favorable effect on the state of spruce stands. Damage to trees occurs mainly in areas with elevated and convex topography and slopes of southwestern aspect, increasing on steeper slopes. The level of die-off is most closely correlated with conditions of the previous year, which is explained by the impact of biological factors (pest insects and phytopathogens) on tree stands already affected by water stress. The decline of spruce stands on a mass scale is also observed in neighboring regions of Russia and counties of East Europe, which is evidence for a low adaptability of spruce to current climate change, including the increasing frequency and severity of dry periods. 相似文献
18.
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
19.
Patterns of expansion of geographical ranges of red deer and Siberian roe deer in Yakutia during the 20th century are considered. The area inhabited by red deer in Yakutia has increased almost fourfold over the past 50 years, with an expansion of over 200000 km2 toward the northwest. The geographical range of roe deer in the Lena–Amga interfluve has also changed considerably during the same period. Roe deer sightings in the subarctic zone were reported. The structure of geographical ranges of the species under investigation in different ecological and geographical regions of Yakutia is discussed, and the factors influencing the transformation of geographical range borders are characterized. 相似文献
20.
Fungal canker caused by Biatorella difformis [Fr.] Rehm. has a deleterious effect on the productivity of Scots pine. Affected trees are characterized by decreased biometric
parameters of shoots and needles and impaired pollen germination and tube growth. Their pollen has reduced contents of reserve
nutrients and physiologically active substances. 相似文献