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1.
Communities of benthic macroinvertebrates in drainless Lake Chany, the largest lake in Western Siberia, have been analyzed to estimate the effects of basic abiotic ecological factors (hydrophysical and hydrochemical parameters of water and the type of bottom ground) on their composition, structure, and dynamics. It has been shown that the level of development of these communities depends mainly on the water regime of the lake and also on the type of bottom ground, lake depth, and water mineral content.  相似文献   

2.
Data on the abundance and occurrence of 64 odonate species in the Southern Urals are considered. A comparative analysis of the odonate fauna in the early 20th century, in the 1960s and 1970s, and in the early 21st century is performed. On this basis, it is concluded that its structure has been markedly changing with time, with the magnitude of these changes being comparable to that of regional faunistic differences. The causes of these changes are discussed. The apparent enrichment of the odonate fauna is attributed primarily to the appearance of new anthropogenic habitats.  相似文献   

3.
Several parameters of energy and immune homeostasis in immature red-backed voles at different phases of the population cycle have been evaluated and compared over three cycles (2002–2009). It has been found that a specific morphophysiological type of population is characteristic of each phase of the cycle. The values of all physiological parameters recorded at high and low population densities significantly differ from each other, with their values being usually intermediate at a medium density. The level of most energy and immune parameters at the phase of population peak corresponds to that observed under stress. Supposedly, stress contributes to suppression of reproduction and increased mortality of the voles.  相似文献   

4.
The structural-temporal organization of a murine rodent community in the taiga has been studied near Lake Teletskoe, Mountain Altai. The results show that the long-term dynamics of indices characterizing community diversity depend mainly on changes in the structure of dominance rather than on the population dynamics of species. The distribution of species in the factor space corresponds to their preference for certain biotopes, from dry to relatively moist. An analysis of relationships within the rodent community has revealed the synchronous dynamics of species abundance and antiphase pattern of changes in the structural indices of dominant species.  相似文献   

5.
Changes in parameters of species richness and dominance in parasite communities of perch have been analyzed in the age series of hosts from two water bodies, Lake Gusinoe and Chivyrkui Bay (Lake Baikal), at the levels of a host individual (infracommunity) and a host age group (set of infracommunities). The species richness of parasite infracommunities has been found to increase in both age series due to decreasing proportions of fish affected by no more than three to four parasite species and increasing proportion of fish parasitized by more than four to five species.  相似文献   

6.
A comparison of two Siberian moth populations from the Altai Republic (feeding on Siberian fir) and the Tyva Republic (feeding on Siberian larch) has revealed no differences between them with respect to ecophysiological parameters of larval growth and feeding on needles of the same conifer species under laboratory conditions. The index of appropriateness of food plants for the larvae from both populations decreases in the series larch > fir > spruce > pine. The age-related dynamics of parameters characterizing the feeding and growth of larvae are independent of the population to which the insects belong.  相似文献   

7.
The results of 25-year monitoring have been used to develop a local approach to analysis of the spatiotemporal population dynamics of rodents. The main processes of the formation of the rodent population structure in a heterogeneous environment have been considered on the basis of experimental quantitative estimates obtained under natural conditions. The possibility of real-time identification of elementary chorological units of a species population has been substantiated. It has been found that complete cycles of vital activity of a model rodent species are usually no longer than 18 months. The strategy of the regional population functioning in species with short individual life cycles is considered at a new angle.  相似文献   

8.
Singular Spectrum Analysis (SSA) has been used to decompose continuous series of data on certain characteristics of Lake Naroch’ ecosystem during the vegetative seasons of years 1978–2015 into a long-time trend, a periodic component, and a residue not amenable to decomposition. The contribution of each component to changes in this variable has been assessed. The trends accounted for 78–97% of parameter variability, and the periodic components accounted for 2.5–15%. The fluctuations of phytoplankton and zooplankton biomass dynamics were the most diverse, and the contribution of these components was the greatest (15 and 8%, respectively). The periodic components in the changes of all parameters could be divided into four groups according to period duration (17–22, 7–15, 4–7, and less than 4 years). Multidimensional factor analysis of seven biotic parameters was performed in order to identify fluctuations in the ecosystem. Five major factors accounting for 93.6% of ecosystem changes together were identified, and each factor variable was subjected to SSA analysis. The period durations were similar for the oscillatory components identified. The first factor was interpreted as a trophic status of the water body, the second was taken to be the geographical location that defines the amount of solar radiation energy available, the third was taken to be the availability of biogenic elements (phosphorus in particular), and the fourth was interpreted as specific developmental cycles of live components of the ecosystem.  相似文献   

9.
The 20-year dynamics of Aporrectodea caliginosa spring population parameters—the average density (ind./0.25 m2) and proportion of nonreproductive individuals (among earthworms found in 12 soil samples)— and the 10-year dynamics of their summer and autumn values were studied in an annually flooded alder forest in the Voronezh reserve. Three complete 3-year cycles and one complete 6-year cycle were revealed in the 20-year dynamics of spring population density. The 20-year series of average values of spring population density and proportion of nonreproductive individuals were found to be closely correlated with each other. A close correlation was also revealed between the 10-year series of summer density values and the corresponding dynamic series of summer precipitation.  相似文献   

10.
Analysis of demographic parameters in a local bank vole population has shown that different relationships exist between them. The level of population abundance is directly correlated with the proportion of sexually mature juveniles, the length of the breeding season, and the age of overwintered individuals. The duration of the breeding season shows a delayed dependence on population abundance in the previous year. Variation in the average age of overwintered voles at different phases of the population cycle is characterized by a delayed dependence on the length of the breeding season in the previous year. Intrinsic factors generate the cyclic dynamics of parameters, while extrinsic factors can modify their dynamics.  相似文献   

11.
Long-term studies (1975–1999) and large amounts of field data (collections and observations on marked animals) have been used to analyze the growth and development of the northern mole vole (Ellobius talpinus Pall., 1770). Data are presented on the postnatal development and life spans of particular age groups of this species and on the dynamics of growth and life spans in the resident and migrant parts of the population. It is shown that the population is divided into slowly growing and rapidly growing groups, which is related to population dynamics. The timing of sexual maturation of the northern mole vole depending on the time of birth is clarified. It is shown that stable reproduction of this underground species is accounted for by the presence of seasonal generations.  相似文献   

12.
The population of foxes in the central regions of Yakutia has grown by a factor of four to five during the period from 2000 to 2011–2012, following an increase in the abundance of voles from the genus Microtus. A total of 130 carcasses of foxes taken in 2007–2012 have been examined. Age- and sex-related variation in morphological features has been described. The demographic structure of the population has been studied by estimating animal age from annual layers in the recording structures. Changes in female fertility and involvement in reproduction depending on age and feeding conditions have been analyzed. Changes in the composition of fox diet caused by long-term population depression in the mountain hare and their effect on the dynamics of fox abundance have been revealed. Age- and sex-related characteristics of the condition factor in foxes and sex-related differences in their dietary preferences have been demonstrated.  相似文献   

13.
Variability of the length of the white area on the outermost quill feathers of the great tit from two cities in the Middle Ural has been investigated. Dynamics of the average length of the white area in the birds from the city of Asbest reproduced the dynamics observed in the city of Yekaterinburg with a one-year lag in the females and a two-year lag in the males. Phenotypic changes in the great tit population did not occur simultaneously in the whole population, but rather moved along the living range with a certain velocity (50–60 km/year for the females and 25–30 km/year for the males). The results obtained are discussed in view of the concepts of population biology.  相似文献   

14.
Quantitative data of winter bird censuses in forest habitats of the Ilmen Nature Reserve (1986–2010) have been analyzed with regard to changes in the monthly average, maximum, and minimum temperatures and precipitation in the period from December to February. No warming trend has been revealed in the reserve over the study period, The dynamics of bird population structure in winter has proved to be independent of weather conditions, despite significant interannual fluctuations. The most significant factors of long-term dynamics of abundance of wintering birds include population density in the previous nesting period, the seed yield of the main food plants, and local migration of wintering species.  相似文献   

15.
湖北省湿地冬季水鸟多样性研究   总被引:12,自引:1,他引:11  
报道了2004年1~4月湖北冬季水鸟调查结果,记录水鸟 66 种,种群数量 59 613 只,分属8目15科,其中列入国家重点保护的一级鸟类 4 种,115 只,国家二级 7 种,2 968 只。分析了冬季水鸟群落结构、分布和种群变动,并用生物多样性指数、物种丰富度与生物量3个不同的测度指标对其中12个湖泊的水鸟群落进行了评价,认为沉湖、梁子湖、龙感湖和网湖是较为成熟稳定的群落;并从沉湖东方白鹳(Ciconia boyciana)、龙感湖白头鹤(Grus monacha)、洪湖鸭科水鸟近40年的种群动态探讨了湿地水鸟现状,认为种群衰退趋势明显、湿地干扰和威胁严重。对此提出了加强湿地保护区的建设,理顺管理体制,合理规划与发展湿地产业和保护湿地资源对策。  相似文献   

16.
The dynamics of wolf attacks on domestic ungulates at the levels of population group (the region of Central Forest Nature Reserve) and population (Tver oblast) have been analyzed over the period of 1971 to 2015. It has been found that the frequency of attacks increases during the phase of predator population growth under the effect of qualitative changes within the population. An increase in the frequency of attacks and the number of sheep and calves killed per attack also takes place in the summer–autumn period, as a consequence of training wolf cubs in methods of killing prey. Therefore, domestic animals are not only a source of food for the wolf but also an object for training the young.  相似文献   

17.
Changes in the distribution and abundance of some game mammals have been analyzed over the past 100–150 years. Correlations between changes in the population density of species in slightly and strongly transformed habitats have been revealed, which show that the influence of anthropogenic factors on the population density of species has a highly complex pattern. Transformation of habitats leads to disturbances in the species composition of communities, changes in the population density of species, and disruption of functional relationships between them.  相似文献   

18.
The dynamics and correlations of ecophysiological parameters have been studied in two spatially separated multispecies communities of murine rodents and ixodid tick larvae and nymphs that parasitize them. It has been shown that all the processes under consideration have nonstationary, oscillatory dynamics. The long-term dynamics of connectivity of ecophysiological characteristics within communities and their synchronization by weather–climatic factors are, by nature, wavelike processes of transitions between the states with stronger and weaker linkage between parameters, which, along with nonstationarity, can contribute to the maintenance of stability and integrity of communities.  相似文献   

19.
Long-term dynamics of population decline can improve the conservation perspectives and strategies for endanger species. In China, new gazetteers having systematic compilation and wide geographical coverage can be considered as an important complementary for reconstruction historical distribution. For historical and cultural reasons, an endangered species–lynx (Lynx lynx) was recorded regularly in new gazetteers. Therefore, the aim of this paper was to evaluate the population distribution in Northeast China from the 1950s to 2014. The data show that Felis lynx was widely distributed in Northeast China in the 1950s, but the number of the occurrence records have been significantly reduced by 85.6% in the last 60 years. This research also enlightens us that the new gazetteers can contribute to data shortage and it would be helpful to conservation biology.  相似文献   

20.
A simulation model, based on original and published data, has been developed to determine the period and amplitude of natural population cycles of wild reindeer on the Taimyr Peninsula and reveal the role of hunting in these cycles. The results of simulations show that hunting in the late 20th century has smoothed out the cycles. Considering natural factors of population regulation, uncontrolled elimination of part of the population by hunting should maintain the average long-term abundance at a level lower than potentially possible under natural dynamics, leading to negative ecological and economic consequences.  相似文献   

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