Population cycles of the bank vole in the range optimum

Patterns of seasonal and long-term dynamics of the size and structure of the bank vole population were studied in the European subtaiga subzone, the optimum of the species range. The dynamics of this population proved to undergo complex fluctuations with cyclic components, which have periods of one year and about three years. The one-year fluctuations of the population size and structure are accounted for by animal adaptation to seasonal changes in environmental factors. The fluctuations with the three-year quasi-period are determined by intrapopulation density-dependent mechanisms.     

Spatiotemporal population structure of the bank vole in a gradient of technogenic environmental pollution

Between 1998 and 2005, specific features of spatiotemporal distribution of small mammals in transformed habitats were studied using the example of the bank vole living in a gradient of chemical environmental pollution (the Middle Urals). Technogenic degradation of spruce-fir forests proved to entail significant changes in the spatial structure and abundance of vole populations. Differences in colonization of disturbed and intact territories by bank voles at different stages of population dynamics were revealed.     

Home range and the expression of nonresidence in bank voles (<Emphasis Type="Italic">Clethrionomys glareolus</Emphasis>): Interpretation of the results of marking at live-trap lines

The distribution of activity of bank voles along a live-trap line can be approximated by the normal law. The standard deviation is a stable characteristic of the sizes of regularly used space. Occurrence of an animal beyond a distance of three standard deviations from the center of activity is regarded as an expression of nonresidence. Different types of space use have been found: equilibrium and drifting home ranges, movements, and excursions. Formal criteria for distinguishing space use patterns are presented.     

Long-term population dynamics of ixodid ticks and development of tick-borne encephalitis foci under conditions of the middle taiga subzone

Long-term (1995–2003) population dynamics of ixodid ticks and their main hosts (small mammals) and conditions providing for the formation of tick-borne encephalitis (TBE) foci were studies in the middle taiga subzone (Karelia). The results show that the bank vole (Clethrionomys glareolus Schr.) is the main host for the larvae and nymphs of Ixodes persulcatus Schulze, 1930 and for the larvae, nymphs, and adult individuals of I. trianguliceps Birula, 1895. The proportion of ticks feeding on this species (relative to their total number) reaches 63.3% (64.0% of I. persulcatus and 61.1% of I. trianguliceps). Activity of a TBE focus is determined primarily by the abundance of bank voles of older age groups.     

北京市人口动态模拟与政策分析

随着城市化进程的加快,我国城市规模不断膨胀,超过1 000万的超大城市不断涌现,城市人口规模过大、增长过快以及带来的城市问题引起社会各界的关注。北京作为一个人口超过2 000万的超大城市,不仅具有超大城市的一般特征,而且具有首都所在城市的特点。本文在厘清北京人口增长机制的基础上,采用系统动力学方法,通过政策模拟,考察不同政策导向对未来北京市人口增长趋势的影响,得到以下结论:1如果保持当前的经济增长速度,并按当前的生产技术水平以及产业结构变化趋势发展,未来北京人口规模将持续快速增长,到2030年将突破3 000万人,2050年将接近5 000万人,城市面临巨大的人口压力。2单纯通过产业结构升级对调控人口作用有限。3适当放缓经济增长速度以及大力提高劳动生产率可以有效控制人口的快速增长,挤出大量的低端劳动力,人口调控效果明显。4户籍制度的适度放开在一定程度上减少了外来人口规模,但对人口总量的减少并没有起到作用。5与单纯采用一种政策调整相比,多种调控政策并举调控人口的效果更佳。由此得到以下几点启示:首先,每个城市都应该有自己的功能定位,决不能搞"大而全"和千城一面,尤其不能将城市经济增长速度和总量作为城市发展的主要目标甚至唯一目标,不顾后果和不择手段地追求GDP。否则城市人口规模的无序扩大就很难避免,也很难治理。对于北京而言,发挥其政治、文化、国际交往以及科技创新中心的首都功能,大力发展现代服务业,提高劳动生产率,优化产业结构才有利于人口的有序发展。另外,政府在人口调控方面必须有所作为,但也不能对人口调控进行大包大揽,取代市场。政府要顺应经济和社会发展的规律,顺势而为,出台相应的系列综合性调控政策。只有这样,才能对人口调控起到更好的效果。     

Fluctuations of Population Size and Structure in the Northern Mole Vole: Preliminary Analysis

Long-term stationary studies on the ecology of the northern mole vole (Ellobius talpinus Pall.), performed by the mark–recapture method from 1985 to 1997, have provided original data on population dynamics and structure. The analysis shows that, to reveal cyclic fluctuations of population size in this species, the period of three years should be taken as a unit of time for estimating the duration of one phase. The 12-year population cycle in E. talpinus has four distinct phases: an increase, a peak, a decline, and a minimum. At each phase, the population is characterized by certain features of family structure, age composition, birth and death rates, and the composition of migrants.     

Comparative Analysis of Coat Color Morphs in a Polymorphic Population of the Northern Mole Vole

Long-term stationary observations (1985–2000) on a polymorphic population of the northern mole vole (Ellobius talpinus Pall.) in Kurgan oblast were performed using the mark-recapture method. Original data were obtained on the abundance and structure of this population, which comprised individuals of three color morphs: black, brown, and intermediate (bicolor). Each morph proved to have its specific features with respect to abundance, age and sex composition, migration, birthrate, mortality, and life span. In general, this polymorphism contributes to population heterogeneity and the maintenance of population homeostasis.     

Population structure and dynamics of Monotarsobius curtipes (Myriapoda, Chilopoda) at the northern periphery of the species range

Studies on the population structure and dynamics of the stone centipede Monotarsobius curtipes C. Koch in soils of the northern Kola Peninsula have shown that, with respect to abundance and biomass, this species is a dominant of the soil macrofauna and, in particular, of the trophic group of zoophages. Life in high northern latitudes does not disturb the sex and age structure of populations but limits the reproductive activity of these centipedes. Specific biological features of M. curtipes at the northern periphery of its range include the absence of repeated breeding, completion of several developmental (age) stages within a short growing season, and long ontogeny involving several winterings.     

上海城市人口郊区化的经济因素分析

研究1990—2004年上海户籍人口分布变动情况。发现1993年上海人口分布变动出现拐点。1994年人口分布变动与郊区化明显活跃。通过建立模型进行模拟。对上海人口郊区化的经济影响因素分析。得出以下结论：人均GDP、城市基础设施投资和住宅投资这三个经济因素对上海城市人口郊区化产生重要影响；上海人均GDP恰好为2000美元时，上海城市人口郊区化明显活跃。这与西方发达国家在人均GDP3000美元时人口郊区化活跃形成对比。     

Analysis of Survival of the Red Fox (Vulpes vulpes L.) at the Phases of Population Growth and Decline

Changes in the survival parameters of the red fox were analyzed at different phases of the population cycle. It was found that the survival rate in all age classes, including newborns, drastically increased at the phase of population growth. The relationship between the general mortality rate and population size was determined. A hypothesis concerning the mechanism of these changes in the general mortality rate is suggested.     

Relationship between the Population Dynamics of the Gypsy Moth (Lymantria dispar L., Lymantriidae: Lepidoptera) and the Genetic Polymorphism of the Nuclear Polyhedrosis Virus

The population dynamics of the gypsy moth and the genomic DNA of the nuclear polyhedrosis virus (NPV) pathogenic for this insect were simultaneously studied using nucleic acid molecular hybridization (NAMH). It was demonstrated that population outbreaks of the gypsy moth were accompanied by an increase in its sensitivity to NPV and in the genetic polymorphism of NPV strains circulating in the insect populations. The hybridization activity of the virus strains isolated at the phase of gypsy moth population growth was significantly higher (p < 0.001) than the activity of the strains isolated at the phase of population decrease.     

城市化发展过程的非线性模拟

模拟城市化发展过程方法提取城市化发展中的人口和经济两个主要因子。根据其相互制约的关系。运用非线性理论构筑城市化发展的非线性模型。并采用定性和定量相结合的方法。进行数值模拟，并构建这一模型。解释城市化发展过程中的部分现象。这一模型是理想状态下实现的。无法取得现实中准确的数值，仍需加以修正才能更精确的模拟城市化发展的现实过程。     

The role of floods in the Long-term dynamics of geobiont and chortobiont communities on islands of the Kuibyshev Reservoir

Interannual changes in geobiont and chortobiont abundance on the islands of Kuibyshev Reservoir are largely determined by flood conditions, because the seasonal average abundance of many taxa is negatively correlated to the water level in May and June. Floods influence the abundance of these animals both directly and indirectly, through biocenotic connections and some aspects of behavior. Long-term positive trends are observed in the abundance of many species. The hypothesis is proposed that this increase in the abundance of geobionts and chortobionts is a consequence of adaptation processes in these communities, which are stimulated by the flood regime of the reservoir.     

Problems of Population Dynamics of the White-Eyed Pochard (Aythya nyrocaGuld., 1770) in the Eastern Sea of Azov Region

The long-term population dynamics of the white-eyed pochard (Aythya nyroca) in the eastern Sea of Azov region was analyzed. It was found that the local population of this species tends to decrease in size. Clutch size, egg size, reproductive behavior, intraspecific clutches, embryonic mortality, and hatching success in this population were studied. The contents of PCDD and PCDF in the eggs of waterfowl were estimated. The eggs of white-eyed pochard, compared to other waterfowl, proved to contain abnormally high concentrations of xenobiotics. Possible causes of A. nyrocapopulation decline, including the impact of superecotoxicants, are discussed.     

Analyzing the carbon dynamics of central European forests: comparison of Biome-BGC simulations with measurements

Biogeochemical models are often used for making projections of future carbon dynamics under scenarios of global change. The aim of this study was to assess the accuracy of the process-based biogeochemical model Biome-BGC for application in central European forests from the lowlands to upper treeline as a pre-requisite for environmental impact assessments. We analyzed model behavior along an altitudinal gradient across the alpine treeline, which provided insights on the sensitivity of simulated average carbon pools to changes in environmental factors. A second set of tests included medium-term (30 years) simulations of carbon fluxes, and a third set of tests focused on daily carbon and water fluxes. Model results were compared to aboveground biomass measurements, leaf area index recordings as well as net ecosystem exchange (NEE) and actual evapotranspiration (AET) measurements. The simulated medium-term forest growth agreed well with measured data. Also daily NEE fluxes were simulated adequately in most cases. Problems were detected when simulating ecosystems close to the upper timberline (overestimation of measured growth and pool sizes), and when simulating daily AET fluxes (overestimation of measured fluxes). The results showed that future applications of Biome-BGC could benefit much from an improvement of model algorithms (e.g., the Q₁₀ model for respiration) as well as from a detailed analysis of the ecological significance of crucial parameters (e.g., the canopy water interception coefficient).     

The narrow-skulled vole (<Emphasis Type="Italic">Microtus gregalis</Emphasis> Pall.) in the dynamics of zonal rodent communities of northern Eurasia

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.     

Hormonal response to conspecific chemical signals as an indicator of seasonal reproduction dynamics in the desert hamster, Phodopus roborovskii

Changes in male blood plasma testosterone and cortisol in response to exposure to scent marks (urine and midventral gland secretion, MVGS) of conspecific males and diestrous females in different seasons have been studied in the desert hamster (Phodopus roborovskii), a species whose ecological features are poorly known. The results show that a significant increase in the plasma testosterone level is observed in winter (only to female MVGS), spring (to female MVGS and urine), and summer (to female urine), but not in autumn. The level of plasma cortisol significantly increases only in response to female urine in spring and male MVGS in summer.