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Morphophysiological and anatomical characters of needles that are used for characterizing infraspecific taxa have been studied in Scotch pine geographic cultures established in the forest-steppe zone of Siberia. Variation in these characters has been revealed, which reflects the polymorphic structure of the species and the effect of natural selection on the composition of populations in new natural-cimatic conditions.  相似文献   

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The structure of the crown and branching; the growth, development, and ontogeny of branches; and organogenesis and growth of female shoots in the model Siberian stone pine trees were studied in four types of habitats at the timberline in the central Altai Mountains (1700–2170 m a.s.l.). The results provided evidence that the ecological forms of trees appear due to changes in the pattern of branching as well as to the decreased rate of vegetative (primarily apical) growth. The diameter of the shoot pith is one of the most variable characters reflecting the deterioration of environmental conditions at higher elevations.  相似文献   

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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   

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The dependence of the annual increment of vegetative organs on air temperature and humidity and the amount of precipitation per phenophase, as well as the period of their growth in Scots pine, were studied in the forest-steppe zone of Cisbaikalia. The multiple effect of variation in environmental conditions on the annual increment of organs increased when precipitation in September of the previous year was taken into account. These factors proved to have a stronger effect on variation in the annual increment of needles (R 2 = 0.59, p = 0.00005) than that in the annual ring width (R 2 = 0.38, p = 0.0002).  相似文献   

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Long-term dynamics of the numbers of complete (normal) veins, venation anomalies, and linear wing parameters were analyzed in male Calopteryx splendens Harr. damselflies from neighboring population groups. Correlation analysis showed that some anomalies may appear additionally to complete veins, whereas other anomalies are formed instead of them. The damselflies from the generations of even years proved to have significantly greater numbers of anomalies. A probable cause of this phenomenon was a sharp increase in the background radiation level in the summer of 1986, after the Chernobyl accident, which could lead to serious hereditary disturbances manifested in a series of generations. The results of the study show that the formation of wing venation anomalies in damselflies is a stochastic process, which is enhanced under the effect of both environmental and genetic stress. These anomalies may be regarded as markers characterizing the degree of stability of ontogenetic processes in the population, which essentially reflect specific genotypic traits of individual organisms. Analysis of wing venation anomalies appears to be a more precise instrument for assessing developmental stability than estimation of the levels of fluctuating asymmetry and general phenotypic variance.  相似文献   

8.
The data on the dynamics of population size and species composition of wasps from the families Pompilidae, Sphecidae, and Vespidae were obtained in the course of long-term studies carried out in successional pine forests of the Berezinskii Biosphere Reserve. The abundance and species diversity of wasps were significantly higher in a polewood forest (40 years) than in a young forest (20 years) and mature moss forest (70 years). In an overgrown ride in the moss pine forest, the composition of dominant wasp species remained relatively stable during the seven-year period of observations, although the number of species and their abundance varied significantly from year to year, depending on the weather.  相似文献   

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Abstract

Shandong Peninsula, as a more developed region in Shandong Province even the east coast of China, is facing challenges from resources and environment pressures. This paper tried to track and assess the coordination status and the dynamic between resource-environment and economy-society systems in Shandong Peninsula during 2001—2008 in order to provide decision support for regional sustainability. An appraisal index system was built including five aspects of harmony degree (A), sustainability degree (B), opening degree (C), stability degree (D) and controllability degree (E). The results showed that: 1) The coordination level of resource-environment and economy-society in Shandong Peninsula has continuously grown, and it has undergone three stages: no coordinated degree (2001–2002), weak coordinated degree (2003–2006) and basically coordinated degree (2007– 2008). 2) Five indexes of criterion hierarchy also increased overall, but each index showed different trends. Harmony degree, sustainability degree and opening degree rose all the time, while stability degree and controllability degree alternately rose and fell. The improvement of controllability degree was the slowest. 3) The aggravating trend of environmental pollution was slowing down. The economic growth was driven by industrial growth and urbanization typically and investment was still the main force to pull the regional economic growth. At the same time, technology and education were becoming more and more important for economic growth. The level of foreign capital utility declined and the geographical advantage of Shandong Peninsula was exerted. Meanwhile some characteristics of knowledge economy were presenting. Water resources become the main constraint factor of fast development in Shandong Peninsula. It is necessary to further strengthen the coordination ability of government on regional sustainable development.  相似文献   

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水资源和土地资源是非常重要的自然资源,是农业经济发展不可或缺的物质要素。水资源与土地资源的合理匹配能够促进区域的资源优势转化为经济增长,从而促进区域农业经济发展。我国是一个人口众多的农业大国,同时也存在水资源与土地资源短缺的问题。本文结合我国农业水土资源自然禀赋与实际利用情况,首先利用中国2003-2013年的分省数据,选取单位耕地面积的广义农业水资源量测度方法和当量系数描述了我国农业水土资源匹配的现实,发现我国农业水资源与土地资源在空间上匹配程度不高,农业生产受到水土资源约束较强,农业水土资源的形成区域与消耗区域在空间上不相匹配;然后,在邻接权重矩阵下采用Moran’s I指数验证我国区域农业经济增长的空间关联性,结果显示我国各省农业经济增长存在显著的空间关系,呈现出高度的集聚性和非均质性。为避免估计结果有偏,本文在此基础上采用空间计量建模及估计方法,加入农业生产人、财、物等控制变量,测度水土匹配度对区域农业经济增长的空间溢出效应。结果显示,水土匹配度对区域农业经济发展的区域内和区域间的溢出效应都显著为正,总体上水土匹配度对区域农业经济发展具有正向的溢出效应,即水土匹配度对本地区农业经济增长具有促进作用;同时,由于相邻区域的水土资源自然禀赋条件类似,而且农业生产中存在"示范效应"和"模仿效应",水土匹配度对相邻地区农业经济增长也具有一定的促进作用。因此,采取相关措施优化农业水土资源匹配关系,对促进我国区域农业经济增长,保障我国粮食安全非常重要。  相似文献   

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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.  相似文献   

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