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1.
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.  相似文献   

2.
Long-term stationary investigations on the islands of the Kuibyshev Reservoir have revealed one of the elements of adaptation of communities of ground beetles to extreme conditions created by prolonged floods. In contrast to hydrologic conditions in the reservoir during the flood, small fluctuations in the water level in summer and autumn have a favorable effect on the community of ground beetles of flooded stations, which are actively repopulated after floodwater recession. Under conditions of the heterogeneous environment created in such areas, different species establish relationships that promote their coexistence.  相似文献   

3.
The species composition and abundance of young-of-the-year fishes have been analyzed in catches made in the upper Volga stretch of the Kuibyshev Reservoir between 1991 and 2009. It has been found that the juvenile abundance of roach and blue bream has decreased, while that of perch, silver bream, and spined loach has increased, with young-of-the-year juveniles of common rudd, tubenose goby, round goby, and black-striped pipefish appearing in catches. The results of the study show that, against the background of juvenile population decline in many spring-spawning fish species, the abundance and species diversity of young of the year in summer-spawning species has increased during the observation period.  相似文献   

4.
Small tropical islands are widely recognized as having high exposure and vulnerability to climate change and other natural hazards. Ocean warming and acidification, changing storm patterns and intensity, and accelerated sea-level rise pose challenges that compound the intrinsic vulnerability of small, remote, island communities. Sustainable development requires robust guidance on the risks associated with natural hazards and climate change, including the potential for island coasts and reefs to keep pace with rising sea levels. Here we review these issues with special attention to their implications for climate-change vulnerability, adaptation, and disaster risk reduction in various island settings. We present new projections for 2010–2100 local sea-level rise (SLR) at 18 island sites, incorporating crustal motion and gravitational fingerprinting, for a range of Intergovernmental Panel on Climate Change global projections and a semi-empirical model. Projected 90-year SLR for the upper limit A1FI scenario with enhanced glacier drawdown ranges from 0.56 to 1.01 m for islands with a measured range of vertical motion from ?0.29 to +0.10 m. We classify tropical small islands into four broad groups comprising continental fragments, volcanic islands, near-atolls and atolls, and high carbonate islands including raised atolls. Because exposure to coastal forcing and hazards varies with island form, this provides a framework for consideration of vulnerability and adaptation strategies. Nevertheless, appropriate measures to adjust for climate change and to mitigate disaster risk depend on a place-based understanding of island landscapes and of processes operating in the coastal biophysical system of individual islands.  相似文献   

5.
虎跳峡坝址为金沙江流域上下游鱼类的分界处,水生生境敏感而脆弱。科学预测水库蓄水对水温的影响,对于研究水库兴建对水生生物的影响,保护金沙江流域鱼类资源,探讨水库泄水对下游农田灌溉作物的影响具有重要意义。综合应用多种水库水温预测模型和方法,对虎跳峡水库蓄水后对库区和下游河道水温的影响进行了预测,并分析了水库泄水对下游灌溉作物的影响。结果表明,虎跳峡水库蓄水后库区水温比蓄水前明显升高,正常蓄水位1 950 m和2 010 m两个方案库区年均水温分别增加5.9℃和5.6℃,且6月~次年1月水温增幅较大;4~9月水库泄水水温比天然河段水温分别低3.5~6.2℃和3.3~7.1℃,两个方案都将对坝下采用干渠取水灌溉的农田作物带来一定的影响。  相似文献   

6.
Field gamma-ray spectrometry was used for the quantitative assessment of U, Th and K of rocks of Stromboli, Salina, Filicuidi and Panarea (Aeolian arc of the Southern Tyrrhenian, Italy). The air absorbed dose rate was calculated from radioelement concentrations. For some rocks the gamma-ray spectra were analysed with the three photo-peak methods and the response matrix method, which converts the pulse height distribution into the true incident gamma-ray energy spectrum. The higher values of U (8.2-9.8 ppm) coincide with higher Th (20.6-27.8 ppm) concentrations associated with rocks of shoshonitic composition. The spatial variation in radioelement concentration reflects the geochemical differences among the rocks. The air absorbed dose rate varies from 25 to 215 nGy h(-1). The highest values correspond to outcrops located in the eastern part of Stromboli, where the annual effective dose equivalent reaches a value of 264 microSv.  相似文献   

7.
Six island or island groups (Marion and Prince Edwards Islands, Iles Crozet, Iles Kerguelen, Heard and McDonald Islands, Macquarie Island, South Georgia) are considered in this account to belong to the sub-Antarctic region. The environments and biota of these islands are described. The vulnerability of their indigenous floras and faunas to introduced alien species is stressed. The sovereignty and administration of the islands and the conservation issues pertaining to them are discussed. Currently, less than 4% of the terrestrial sub-Antarctic is under statutory protection. Conservation and protection of the sub-Antarctic islands must be based on consideration of the conservation of the southern ocean as a whole.  相似文献   

8.
9.
Foliar damage to aspen from leaf-chewing insects and miners has been assessed during a 4-year period in the environs of a large copper smelter in the Middle Urals. It has been shown that the total area removed, proportion of damaged leaves, and average area removed per damaged leaf are considerably smaller near the smelter than in the background zone. The degree of the effect is similar for all three parameters and remains stable with time. Both groups of leaf pests display lower trophic activity in the impact zone, but the effect of pollution on leaf-chewing insects is greater than on miners, while individual features of the tree and its environment affect miners more strongly than leaf-chewing insects.  相似文献   

10.
Regional Environmental Change - The numerous Mediterranean islands (>10,000) are very important from a biodiversity point of view, both in term of plant species (numerous endemics, presence...  相似文献   

11.
Abstract

Reservoir water environment is a grey system. The grey clustering method is applied to assessing the reservoir water environment to establish a relatively complete model suitable for the reservoir eutrophication evaluation and appropriately evaluate the quality of reservoir water, providing evidence for reservoir management. According to China’s lakes and reservoir eutrophication criteria and the characteristics of China’s eutrophication, as well as certain evaluation indices, the degree of eutrophication is classified into six categories with the utilization of grey classified whitening weight function to represent the boundaries of classification, to determine the clustering weight and clustering coefficient of each index in grey classifications, and the classification of each clustering object. The comprehensive evaluation of reservoir eutrophication is established on such a foundation, with Sichuan Shengzhong Reservoir as the survey object and the analysis of the data attained by several typical monitoring points there in 2006. It is found that eutrophication of Tiebian Power Generation Station, Guoyuanchang and Dashiqiao Bridge is the heaviest, Tielusi and Qinggangya the second, and Lijiaba the least. The eutrophication of this reservoir is closely relevant to the irrational exploitation in its surrounding areas, especially to the aggravation of the non-point source pollution and the increase of net-culture fishing. Therefore, it is feasible to use grey clustering in environment quality evaluation, and the point lies in the correct division of grey whitening function  相似文献   

12.
Reservoir water environment is a grey system. The grey clustering method is applied to assessing the reservoir water enviromnent to establish a relatively complete model suitable for the reservoir eutrophication evaluation and appropriately evaluate the quality of reservoir water, providing evidence for reservoir management. According to China's lakes and reservoir eutrophication criteria and the characteristics of China's eutrophication, as well as certain evaluation indices, the degree of eutrophication is classified into six categories with the utilization of grey classified whitening weight function to represent the boundaries of classification, to determine the clustering weight and clustering coefficient of each index in grey classifications, and the classification of each clustering object. The comprehensive evaluation of reservoir eutrophication is established on such a foundation, with Sichuan Shengzhong Reservoir as the survey object and the analysis of the data attained by several typical monitoring points there in 2006. It is found that eutrophication of Tiebian Power Generation Station, Guoyuanchang and Dashiqiao Bridge is the heaviest, Tielusi and Qinggangya the second, and Lijiaba the least. The eutrophication of this reservoir is closely relevant to the irrational exploitation in its surrounding areas, especially to the aggravation of the non-point source pollution and the increase of net-culture fishing. Therefore, it is feasible to use grey clustering in environment quality evaluation, and the point lies in the correct division of grey whitening function  相似文献   

13.
Regional Environmental Change - The characterization of Pacific Islands as especially vulnerable to climate change often undervalues the cultural resilience of their inhabitants. On many...  相似文献   

14.
Regional Environmental Change - Small Island Developing States (SIDS) are widely recognised as being very vulnerable to the impacts of climate change. In some manner, climate change will impact on...  相似文献   

15.
On the basis of long-term monitoring of macrozoobenthos in the Volgograd Reservoir, the causes of changes in its species composition were analyzed and invading species were identified. During the first 20–25 years after construction of the reservoir, invading species appeared at a rate of 0.4 species per year. In the subsequent years, this rate increased to one species per year due to spontaneous expansion of species and the remote effect of their introduction.  相似文献   

16.
公用事业民营化及其环境行为政府管制的研究   总被引:1,自引:0,他引:1  
公用事业民营化的目的是在公用事业行业引入民间资本和市场竞争模式,提高公共产品服务的产出质量和效率。以电力行业的民营化为例,电力市场对于民营企业的开放能够在很大程度上提高我国电力生产水平.解决当前电力供求关系紧张的问题。但是,大量民营企业介入电力生产,由于其技术落后而导致的资源浪费以及污染物的无序排放给我国的环境保护带来了新的困扰。我们应该在科学发展观和构建社会主义和谐社会的目标指引下,加强政府对于电力企业等公用事业民营化企业生产经营活动的法律管制,同时加强和完善相关的环境立法,达到公用事业积极发展和环境保护目标实现的双赢目标。  相似文献   

17.
Community-based adaptation (CBA) seeks to address climate risks and socio-economic drivers of vulnerability simultaneously. However, as CBA activities appear very similar to standard development work, difficulties in identifying good practices arise. To clarify the role of CBA, this study elucidated how climate change can impact pre-existing development problems by investigating the experiences of four low-lying island communities in central Philippines. The islands currently suffer from frequent and extreme tidal flooding (following an earthquake-induced land subsidence in 2013, with a magnitude that is broadly similar to sea-level rise projections under a 1.5 to 2 °C global warming scenario), and endured a dry spell in 2016. The study also identified various publicly and privately initiated adaptation strategies, and evaluated their resilience against actual biophysical events. The study conducted focus group discussions with local leaders and in-depth interviews with government officials and residents in March 2016. Results show that tidal flooding impacted almost all aspects of daily life on the islands, while the dry spell completely depleted their limited water supplies. The strategies implemented by governments and NGOs (e.g., seawalls, rainwater collectors) were found to be inadequate in preventing tidal flooding and compensating for the dry spell. Also, communities used coral stones and plastic waste for raising the floors of their homes, which have an erosive effect on their capacity to adapt in the long term. Lack of community participation in publicly initiated projects and lack of adaptation funding for community-based strategies were the greatest obstacles to implementing climate-resilient solutions.  相似文献   

18.
Along with the economic development and the acceleration of urbanization, urban construction land expands rapidly in China, and has resulted in a series of socio-economic problems. This article summarized the major points of controlling the unchecked and rash expansion of construction land in the academic circle, and analyzed the problems of regulating the expansion of construction land from three aspects. First, this article analyzed the relationships between socio-economic development and urbaniza- tion from the historical viewpoints, and pointed out that the expan- sion of construction land is a historical phenomenon which will be surely appeared in the development of human race. Second, the authors utilized two-sector model to analyze the importance of urbanization in the socio-economic development from the academic angles. At last, the authors utilize four-quadrant model and bidrent curve model to analyze the influence that brought by the strict control of construction land expansion. Through analysis, this article drew some conclusions. First, the expansion of construction land is a phenomenon which will surely appear in the social development. It is impossible to accomplish the national modernization on the basis of dualistic structure between urban and rural areas. Second, under the function of rent gradient gap, strict control of construction land expansion will not only obtain the anticipated effects, but also cause a series of socio-economic problems, such as land-levying contradiction, the appearance of limited property right house, and being dependant on lease instead of expropriation. Third, unreasonable policies and governmental behaviors are the roots of the unchecked and rash expansion of urban construction land. Based on these conclusions, this article proposed that three transformations should be realized to regulate the unchecked and rash expansion of construction land: transfers from quantity regulation to quality regulation, from direct regulation to indirect regulation, and from single-measure regulation to multi-measures regulation.  相似文献   

19.
基于调节聚焦理论的生物农药推广有效性研究   总被引:2,自引:0,他引:2  
化学农药在提高单位耕地面积农产品产量和效益的同时,由于过量施用、利用效率低下等污染了生态环境、危害农产品安全和损害消费者健康等问题,而具有低残留、低污染和环境友好性优势的生物农药逐渐得到公共部门和业界的重视。但生物农药能否得到大范围推广和施用,关键在于能否改变农户的农药施用行为和农药生产企业的积极参与。由于生物农药施用涉及农户的当前利益和长期利益、个人利益和社会利益等相关因素,使农户的农药施用决策具有突出的心理距离属性。本文引入调节聚焦理论,建立了心理距离与农户农药施用决策和心理动机的关系,实证研究生物农药推广对农户农药施用决策、支付愿意(WTP)、农药生产企业态度和再次施用意愿的影响。结论如下:1施用生物农药给农户带来的收益是长期的、全社会的和不确定的,而多数农户农药施用决策所考虑的利益是当前的、私人的。因此,二者在心理距离、调节聚焦以及利益追求方面是不匹配的,这揭示了当前生物农药推广过程中出现的叫好不叫座的原因;2农药生产企业能够从生物农药推广中获利。如果生物农药推广得当,将会提高农户对生物农药以及农药生产企业的积极评价,其对生物农药的愿意支付价格和再次施用意愿也会提升;3调节聚集信息诉求和心理距离的匹配,对农户生物农药施用决策存在显著影响。当预防(或促进)聚焦信息诉求与近(或远)心理距离匹配时,农户对生物农药信息诉求的认同度较高,施用意愿也更高。因此,要提高生物农药的推广效果,针对农户农药施用决策具有近心理距离的特点,公共部门及农药生产企业在推广生物农药时应该强化预防聚焦信息,而弱化促进聚焦信息;此外,生物农药推广过程中,公共部门及农药生产企业也可以通过宣传策略,延长农户农药施用决策时的心理距离与改善生态环境的促进聚焦目标相匹配,从而提高农户施用生物农药的积极性。  相似文献   

20.
In the zone of heated water discharge and at the control site of the Beloyarsk Reservoir, the phytoplankton was characterized by dominance of blue-green, green, and pyrrophyte algae, and the zooplankton, by the prevalence of crustaceans over rotifers. The study sites differed in the species and quantitative composition of the dominant complex, but the total abundance and biomass of the phytoplankton in the heated zone and the control site did not differ significantly. In Teplyi Bay, the zooplankton was inhibited, which was manifested in the decrease of its abundance and biomass by four and seven times, respectively, in comparison with the control. Radionuclide concentrations in the plankton of the cooling reservoir in the period between 1986 and 1988 were determined. It was found that radionuclide concentration in the plankton is higher in the zone of heated water discharge than beyond it.  相似文献   

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