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1.
The seasonal growth of shoots, needles, and the trunk in the Norway spruce has been studied in a bilberry spruce forest in the middle taiga subzone of Karelia. The results show that the growth of vegetative organs in this tree species depends mainly on the air temperature regime, whereas the effect of variations in factors such as the period of sunshine, precipitation, and air humidity is relatively weak.  相似文献   

2.
The physiological method for estimating production based on the relationship between growth and energy metabolism has been used for calculating model growth curves for the amphipod Monoporeia affinis and comparing them with the results of field studies. Calculations demonstrated that the physiological growth curves fit the results of field observations best under certain conditions which have zoological sense: the growth curve should reflect the actual maximum body size of an animal in the given population, the duration of the life cycle, and the time required for reaching the reproductive size.  相似文献   

3.
Multivariate analysis of variation in the metric characters in the ground beetle C. granulatus has been performed. It has been shown that the beetle body size increases toward the center of its range, urbanization has a positive effect on all metric traits, but the effect of habitat vegetation has no definite trend. The structure of variation in the metric characters estimated by the principal components method depends on all ecological factors considered: the locality in the geographic range, level of anthropogenic influence, and degree of biotope openness.  相似文献   

4.
The geographic variation of the water vole Arvicola terrestris L. has been analyzed with respect to two linear combinations of craniometric characters with the highest additive heritability (h 2 = 0.59 and h 2 = 0.52). The greatest differences have been revealed between the territorially close montane and piedmont populations. The lowland and montane populations have proved to differ to the smallest extent, despite their spatial and altitudinal separation. Selection under extreme conditions that leads to similar phenotypic results may be based on the common genetic background of these populations, irrespective of considerable distances between them and different environmental conditions in their habitats.  相似文献   

5.
6.
Olive (Olea europaea L.) is a drought-tolerant tree which is usually grown in areas with a Mediterranean climate that receive >350 mm of annual rainfall. However, olive growing in Syria has recently expanded into drier areas (200–300 mm annual rainfall) where irrigation resources are limited. This study, carried out between November 2002 and October 2005, aimed to investigate the response of a little known Syrian drought-tolerant olive variety (Qaisi) to water harvesting and limited summer irrigation (200 l per tree) in an arid area (average annual rainfall of 210 mm) with Mediterranean climate in Syria. Soil moisture and growth of four-year-old trees were monitored regularly. Olive leaves were sampled at different stages to determine water content, specific mass, and N content. Stomatal conductance was also measured in 2005. Our results showed that water harvesting and summer irrigation improved soil moisture content, leaf water content (up to 36% higher in Sep. 2003), leaf N content (up to 45% higher in Aug. 2003), leaf stomatal conductance (up to 55% higher in Apr. 2005), and relative trunk growth rate. Water harvesting was most successful in wet years, although the water storage capacity was not enough to retain all harvested water. This study indicated that it is possible to grow drought-tolerant olive varieties in arid areas under little or no irrigation, but proper water and nutrient management should be considered for sustainable growth.  相似文献   

7.
The environmental influence on Chernobyl-derived 137Cs levels in perch (Perca fluviatilis L.) and roach (Rutilus rutilus L.) was revealed using partial least-squares regression (PLS). The 53 environmental predictors used describe land use in catchment areas, various catchment area and lake characteristics, lake water chemistry, and fish stock composition. The study showed a profound effect of land use on the 137Cs levels in fish. Radiocaesium deposited on arable land was retained in the soil to a greater extent than was 137Cs deposited on wetlands, which more easily leached out to the lake ecosystems. The 137Cs deposition close to the lakes had a more pronounced effect on 137Cs levels in the fish than did more distant deposition. The radiocaesium bioavailability is mainly governed by lake water cation content, as hardwater lakes had significantly lower 137Cs content in fish. Resuspension of 137Cs contaminated sediments only had a limited influence on the observed levels in fish.  相似文献   

8.
The data on the ecology of bilberry and cowberry in the West Siberian Plain, Kuznetsk Ala Tau, and highland Altai are presented. Ecological ranges of these plants and amplitudes of their tolerance for some environmental factors are described.  相似文献   

9.
In this study, wild three-spined sticklebacks were sampled every six weeks, between April and October, in a low contaminated stream. For all fish, physiological indexes, such as condition factor, hepato-, gonado- and nephro-somatic index were calculated to determine fish condition and reproductive status. Moreover, a set of biomarkers including biotransformation enzymes, oxidative stress parameters, neurotoxicity and endocrine disruption markers was measured. The results allowed to determine biomarker variability due to fish gender or sampling season. For example, 7-ethoxyresorufin-O-deethylase activity, glutathione peroxidase as well as vitellogenin and spiggin exhibited strong gender differences. Conversely, lipoperoxidation and acethylcholinesterase activity were characterised by a lack of gender and seasonal variation, and can be considered as more robust parameters for a field application. The present work allowed to establish practical guideline for biomarker measurements in wild sticklebacks and to define a reference system which can be used to analyze variations in future monitoring studies.  相似文献   

10.
The placement of 1918 redwing nests has been analyzed, including 214 nests of 90 marked females (2–8 known nests per female). A high level of intraspecific and individual variation in utilization of different types of nest supports is described. It is shown that redwings choose nest sites without regard to previous experience (either positive or negative) or to the placement of their parent nest. Under conditions of the northern taiga, such behavior provides for significant reduction of chick mortality by the end of the season. This is con- firmed by comparison with the song thrush (T. philomelos), which nests mainly on spruce trees.  相似文献   

11.
Giant reed (Arundo donax L.) was grown on surface soil and irrigated with mixed heavy metal solutions of Cd(II) and Ni(II) to study the impact of these heavy metals on its growth and photosynthesis. The tested concentrations were 5, 50, and 100 ppm for each heavy metal against the control and resulted in high cadmium and nickel (DTPA extractable) concentrations in the top zone of the pot soil. The examined parameters, namely, stem height and diameter, number of nodes, fresh and dry weight of leaves, and net photosynthesis (Pn) were not affected, indicating that plants tolerate the high concentrations of Cd and Ni. As giant reed plants are very promising energy plants, they can be cultivated in contaminated soils to provide biomass for energy production purposes.  相似文献   

12.
The distribution of tree species in the landscape was studied using the approach based on the comparison of the ecological requirements of species and the properties of ecotopes distinguished by their position in the relief and peculiarities of basement rocks. The types and specificity of ecological regimes were determined for the typical ecotopes of the southern Karelian ridge landscape. The main environmental and successional factors determining the distribution of seven forest-forming tree species in the ecotopes of this landscape were identified. The results of this work can provide a basis for the prognosis of forest vegetation in the landscape studied.  相似文献   

13.
The paper is devoted to the ecology of the Pied Flycatcher in Southern Karelia, where climate warming has had almost no effect on the weather in spring, the season especially important for birds. During the 30-year observation period, the local population has been characterized by variable breeding phenology, high fecundity, and relatively stable abundance. This appears to be related to the broad norm of reaction of this species to the action of external factors, which allows the birds to flexibly respond to changes in the unstable spring weather and adjust the timing and rates of their seasonal activities.  相似文献   

14.
The return of willow ptarmigans to the sites in which they nested the previous year has been studied using color banding. No factors influencing the return index have been revealed, except for its dependence in males on the time when spring begins in a given year. In northernYamal, in contrast to the temperate zone, some surviving birds fail to return to their former nesting sites. Polymorphism of individuals with respect to territorial behavioral strategy is proposed for L. lagopus populations at the northern boundary of the species range.__________Translated from Ekologiya, No. 3, 2005, pp. 215–221.Original Russian Text Copyright © 2005 by Tarasov.  相似文献   

15.
Experiments on daily exposure of gypsy moth larvae to heat stress have shown that it leads to an increase in the survival rate of larvae with reduced adaptation to artificial diet (AD) and a decrease in the survival rate of larvae well adapted to AD. It has been found that acetylcholine esterase and tyrosinase activities and the concentration of tyrosine derivatives are reduced significantly in stress-exposed larvae. The conclusion is drawn about a possible relationship between change in the level of larval adaptation to food and a switch in metabolism of tyrosine derivatives from hormone synthesis to melanin synthesis pathway.  相似文献   

16.
It is established that the activity of marmots (the genusMarmota) on the surface is timed to the daylight period. In the Arctic, under conditions of continuous illumination (the polar day), the diurnal rhythm of black-capped marmotsMarmota camtschatica bungei on the surface has a “daylight” pattern. The main external regulator of the diurnal rhythm is the altitude of the sun above the horizon. In the cold period, however, the effect of air temperature on animal activity becomes stronger.  相似文献   

17.
The role of moose in the dynamics of structural, physical, and chemical parameters of a forest community is considered using an example of a southern taiga wood-sorrel spruce forest. It is shown that the activities of these animals affect the vertical structure of the underbrush and understory layers, the dynamics of phytomass accumulation, and the state of the ground vegetation. Changes in the nitrogen and hydrocarbon flows through the ecosystem under the effects of moose activities are analyzed.  相似文献   

18.
Russian Journal of Ecology - The proportion of jointly visited traps and the frequency of visits to the traps recorded during mark–recapture studies have been compared with the mathematical...  相似文献   

19.
Data on the daily activity and mobility of the common shrew (Sorex araneusL.) were obtained by the method of animal marking and recapturing in test plots. Sex- and age-related differences in the locomotor activity of animals were revealed, which depended on population size and the phase of the population cycle. Under natural conditions, animal activity in the daytime proved to decrease to a lesser extent than in captivity. The mobility (locomotor activity) of shrews was shown to depend on population density, reproductive rate, and weather.  相似文献   

20.
To reveal the effect of forest fires on the avifauna of the Northern Amur Region, bird assemblages of primary dark conifer-deciduous forests, wild rosemary larch forests, and secondary larch-birch forests have been studied in the Komsomol’skii and Norskii nature reserves. It has been shown that the replacement of primary dark conifer-deciduous forests by secondary forests is accompanied by a significant decrease in bird population density, with some species being lost and the composition of the dominant species group being changed. On the other hand, fires lead to increasing patchiness of the environment, which can sometimes provide for an increase in biological diversity.  相似文献   

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