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1.
The main regulatory mechanism of populations is revealed for some insect groups (Carabidae, Curculionidae, Chrysomelidae, and Hemiptera) on islands of the Kuibyshev Reservoir. This mechanism is the dynamics of the ratio of species with imaginal and preimaginal winter diapause. The extent of these dynamics depends on the stability of habitats, which in turn depends on water-level conditions in the reservoir. The period of adaptation of the community of carabids of the most flooded biotope to the extreme impact of water conditions is determined.  相似文献   

2.
基于新制度经济学视角的“河长制”评析   总被引:8,自引:0,他引:8  
我国频发的水危机既是水环境作为居住地、供应站功能而引发的生态破坏问题,也是作为废物库功能而引发的环境污染问题.河长制是地方政府为了重新恢复环境三大功能协调运行而发明的一项有效的实用制度.河长制因其简单易行,很快在全国形成扩散效应.河长制是源于地方政府的制度创新,本文运用新制度经济学分析了河长制的优缺点:优点是职责归属明确,权责清晰;是合理的路径依赖基础上的制度创薪;铁腕治污提高治污效率;创新扩散机制值得提倡.河长制本身存在制度缺陷:无法根除委托-代理问题;缺乏透明的监督机制;容易出现利益合谋;忽视了社会力量;行政问责很难落实.河长制综合考虑了地方权力结构与环境现实,充分利用行政长官手中的权力带动地方政府职能转变,推动了具有中国本土特色环境制度变迁的步伐.但河长制具有应急的过渡性,应在发展中扬长避短,不断完善,应通过它形成全社会参与环境管理的机制,建立可持续发展的环境治理制度.  相似文献   

3.
The article establishes an evaluation index system of the intensive land use from the perspective of enterprises. It is based on the questionnaire survey and evaluates the levels of the intensive use of the land in the electrical machinery and equipment manufacturing industry in Changzhou, Nantong, and Yancheng of Jiangsu Province. The evaluation result shows that there is obvious difference in the levels of the intensive use of the land in this industry in the three cities. The present article makes a detailed analysis on the causes of the difference. The analysis shows difference in results of the socio-economic and urban development stage, industrial features, population density, and technological progress. Finally, it proposes some suggestions to improve the efficiency of the industrial land use.  相似文献   

4.
A methodology of substantiating the ecological risk of technogenic soil pollution has been described according to the results of bioindication using microfungal communities. At the first state, the values of the factors under which the frequency of each species is maximal were estimated using ordination methods. The statistical distribution of the species sensitivity was simulated according to these data. The methodology was illustrated using the results of analysis of the toxicity of soil samples from uranium mine dumps (the village of Kadzhi-Sai, Kyrgyzstan). The preliminary estimates of the critical values of six soil pollution indices that provide the defined allowable probability of the ecological risk have been given.  相似文献   

5.
The study of relationships between symbiotic fungi and germinating seeds of the Orchidaceae showed that the effect of a fungus on germination depends on the presence of seed dormancy and its pattern. The specificity of symbiosis varies widely. The development of symbiotic sprouts in situand in vitro differs only in the rate, whereas the morphogenesis of asymbiotic sprouts is characterized by several anomalies.  相似文献   

6.
基于生态安全的三峡库区重庆段土地利用冲突识别   总被引:4,自引:0,他引:4  
以三峡库区重庆段为研究区,基于生态安全视角,以生态敏感性与生态系统服务功能重要性评价结果提取生态源地,采用最小累积阻力模型构建生态安全格局,在生态安全格局基础上对三峡库区重庆段2015年的土地利用冲突进行识别,以期为三峡库区重庆段土地利用规划管理提供参考依据。结果表明:(1)耕地冲突分布较为分散,极严重冲突集中分布于奉节县、开县、石柱县与涪陵区,严重与较严重冲突集中分布于重庆市主城区的外围区县,一般与不冲突集中分布于长寿区和巴南区;(2)建设用地冲突分布较为集中,极严重冲突集中分布于重庆市主城区,严重和较严重冲突分布较为分散,各区县均有分布,一般和不冲突也集中分布于重庆市主城区,且大多位于极严重冲突的外围;(3)综合土地利用冲突的极严重冲突集中分布于重庆市主城区的中心区域与奉节县,严重与较严重冲突各区县均有分布,一般与不冲突集中分布于极严重冲突的外围区域。  相似文献   

7.
The leaves of 22 woody and herbaceous plant species growing in urban ecosystems of Kalinigrad were analyzed for the total contents of water-soluble antioxidants (TAC) and polyphenol contents. The soils of test plots were assayed for lead contents in the accumulative horizon. A significant excess over the background Pb level was revealed in soil samples from residential and industrial/utility areas (42% of the city territory), and TAC in plant tissues was found to decrease with an increase in Pb concentration in the soil. The role of polyphenols in forming the antioxidant potential of urban plants growing under conditions of technogenic soil pollution was evaluated. Based on cluster analysis of the water-soluble antioxidant and polyphenol accumulation patterns, the plants were classified into four groups. The results of this study may be used for comprehensive assessment of the resilience of urban plants to anthropogenic impact and improvement of the approaches and methods for monitoring industrial pollution in urban areas.  相似文献   

8.
The results of the census of stray dogs and data on their territorial distribution in the city of Petrozavodsk are reported. The population density of these animals has been found to vary within the urban area, depending mainly on the availability of secluded areas to live in and on population control by municipal services.  相似文献   

9.
沉积物的粒级组成特征对于分析湿地沉积环境和搬运趋势有着重要意义。基于自然保护区沉积物样品,利用粒度分析、Shepard三角图、C-M图、端元分析和GSTA搬运趋势模型,研究分析了鄱阳湖南矶湿地沉积物的粒级组成特征、沉积类型、动力环境和泥沙搬运趋势。结果表明,鄱阳湖南矶湿地沉积物主要以细粉砂为主,平均值为55.35%。沉积物粒度参数中平均粒径均值为5.24Φ,空间分布上具有由西南至东北Φ值逐渐减小的趋势。沉积物质地类型主要为粉砂、粘土质粉砂、砂质粉砂和粉砂质砂,其中粉砂约占62.5%。端元分析的结果显示EM1和EM2可能与鄱阳湖本身湖流带来的沉积物搬运有关,EM3则指示了赣江泥沙来源,EM4可能与局地小环境的水动力变化有关。鄱阳湖南矶湿地沉积物粒径趋势格局以东部向西部、北部向南部最为显著,鄱阳湖南矶湿地是在赣江与鄱阳湖之间复杂交互作用下形成。  相似文献   

10.
The reproduction dynamics of nonsynanthropic rodents living in urbanized areas was compared with that of rodents from natural communities. The number of females in a community and the number of embryos and placental spots per female were estimated. The mechanisms providing for the maintenance of population size were different in different habitats. In particular, the urban communities of murine rodents proved to have a higher reproductive potential.  相似文献   

11.
以加入WTO为标志.中国积极参与经济全球化已成为一种必然.但由于我国的国土规模、自然环境、气候条件等方面的地区差异很大,地区之间在发展水平上一直存在着差距,地区发展不平衡是个长期的国内政治经济现象.这种地区发展的差距表现为各类地区融入经济全球化的程度不同,反应不同.有些地区能够借助经济的全球化而发展自身,有些地区则无法从中受益,甚至因而处于更加落后的境地.本文从三大经济地带、各经济区和各省(市)区三个屡次分析和探讨了不同区域对经济全球化响应的差异,并对全球化条件下我国内部区域一体化格局进行了深入的研究.  相似文献   

12.
An analysis has been made of changes in the mineral composition of conifer needles in northern taiga forests after reduction of emissions from the Severonickel Copper-Nickel Smelter Complex in the city of Monchegorsk, the most powerful source of air pollution in Northern Europe. The data obtained in permanent monitoring plots in 1991, 1993, 2000, and 2007 have been compared. The results provide evidence for reduction in the concentrations of heavy metals (Cu, Ni, Fe) and sulfur in the needles of spruce and pine trees in areas with different levels of air pollution. However, mineral nutrition of conifers has not been optimized. The plants are insufficiently supplied with nutrient elements such as P, Mg, Mn, and Zn. The contents of these and other elements essential for the normal functioning of needles (in particular, Ca, K, and P) continue to decrease, especially in pollution-induced sparse spruce forests. The most significant alterations of nutrient regime have been revealed in the Siberian spruce.  相似文献   

13.
The objective of the research was to create improved understanding of the significance of diverse factors for the total greenhouse gas (GHG) emissions of buildings. The specific focus of the study was on the assessment of the significance of building materials and embodied carbon. The scope of the study covers multi-storey residential buildings in Finland. This research was based on a literature survey and supported by a parametric case study. The parametric study assessed the building-material-related GHG emissions relative to total GHG emissions and the possible range of variation. The research assesses the minimum and maximum GHG emissions for production of buildings with similar spaces, to reveal the likely range of variation for the emissions. The calculations for the ‘minimum’ and ‘maximum’ scenarios assume a similar purpose of use, occupancy and spaces in the building, while the production methods, materials, site conditions and location are varied. The research also assesses the relative importance of various building components and other calculation parameters in terms of GHGs. Total material-related GHG emissions were compared with the GHG emissions caused by the operation of the building, at three distinct levels of energy performance. In addition, the material- and operation-related GHG emissions were compared with the location-related GHG emissions arising from people's mobility.  相似文献   

14.
The abundance and trophic structure of zooplankton along the longitudinal profile of two typical rivers in the Yaroslavl sector of the Volga region are determined by anthropogenic and zoogenic factors. The distribution of zooplankton under the influence of these factors is described by the concept of patch dynamics. The abundance of zooplankton reaches the highest values in the ameliorated upper reaches of rivers and in beaver ponds.  相似文献   

15.
能源、环境与经济是人类社会生存与发展的物质基础,能源经济发展在带来区域经济快速繁荣的同时,往往造成当地社会生活质量的下降和生态环境的破坏。陕西作为我国21世纪重要的能源接续地,在能源开发利用的同时也受到脆弱生态环境的约束,本文以此为例进行可持续发展预警实证研究具有一定的代表性和现实意义。通过设计能源-环境-经济可持续发展预警指标体系,构建出可持续发展预警模型,采用人工神经网络预警方法和层次分析法,编写出计算运行程序,运用Matlab7.1软件中人工神经网络工具箱,将有关数据信息和预警模型有机结合,探讨能源-环境-经济可持续发展理论构建与应用问题。研究结果表明:陕西能源-环境-经济的可持续发展趋势在2000-2014年间分别处于重警、中警、轻警和无警四种状态,基本符合陕西能源产业发展现状;所设计的预警指标能较好地反映出能源-环境-经济可持续发展的特征;基于BP人工神经网络的预警方法具有较强的仿真能力,能提高可持续发展预警的准确性,在能源产业可持续发展预警研究中具有一定的应用价值。  相似文献   

16.
The dynamics of three most abundant mesozooplankton species in the coastal zone of the Gulf of Riga--Bosmina longispina, Synchaeta baltica, Keratella quadrata--is analyzed to detect the regulating environmental factors. The only significant downward trend of species abundance was found for S. baltica in autumn. Statistically significant correlation was estimated only between the summer salinity and the abundance of B. longispina. K. quadrata though showed a negative correlation with summer salinity. The abundance of S. baltica had only nonsignificant correlations with the environmental factors. The abundance of coastal mesozooplankton species is determined by the combination of hydrological regime, predation pressure, benthic conditions and the success of living strategy. The change of fresh- and saline water masses at the coastal areas supplies sufficient food amount but can cause decline in hatching abilities.  相似文献   

17.
The transparency of the forest canopy of lichen-green moss pine forests was estimated for different numbers of sectors of the celestial hemisphere. The ecological contents of these estimations are discussed. The dominance frequencies of species of the herbaceous-dwarf shrub and moss-lichen layers were analyzed. Based on the results of this analysis, it was concluded that the transparency estimated for the zenith sector alone better reflects the influence of leaf debris and the rainfall interception by the crowns. If the transparency was estimated taking into account all sectors of the celestial hemisphere, the effect of community disturbance increased and the redistribution of rainfall was masked.  相似文献   

18.
建立科学有效的评价方法将有助于稳步推进我国的生态工业园建设.而园区所处区域的特点对于评价指标的选择和评价体系的建立具有重要影响。本研究在借鉴国内外最新研究成果的基础上.针对北京工业开发区的发展现状和特点.考虑相关性、可操作等原则,初步提出了一套生态工业园评价指标体系框架及其计算评价方法。评价指标共分为6大类准则,共计25个具体指标.划分为“控制性”指标和“指导性”指标。前者包括:信息基建共事类指标、管理与发展类指标、减量消耗类指标、园区环保类指标。后者包括:循环利用类指标和产业共生类指标。该指标体系蕴涵的思想和理论方法已成为推进北京生态工业园建设的重要借鉴,也可作为国家生态工业园评价方法研究的有益补充。  相似文献   

19.
山西太原都市型现代农业主导产业选择分析   总被引:5,自引:0,他引:5  
都市型现代农业是我国现代农业的重要表现形式.积极发展都市型现代农业,是大城市现代农业发展的战略取向.然而,在都市农业发展的进程中,主导产业具有极其重要的作用.本文简要回顾了以往的主导产业理论与选择基准,运用区位商法与显示性对称比较优势指数法分析了太原市农业结构内部各行业的比较优势.结果表明:农业的优势区域是尖草坪区、清徐县和小店区;林业在迎泽区、杏花岭区和娄烦县的比较优势明显;种植业在杏花岭区、阳曲县、迎泽区等区县比较优势明显;渔业的生产优势区域为娄烦县、晋源区和迎泽区.籍此,结合太原市的资源禀赋、区位条件等优势,积极选择与识别能够带动太原都市农业快速发展的主导产业,并且结合太原农业发展的现实情况,按照观光休闲农业圈、特色种养农业圈、科技示范农业圈及合作辐射农业圈四个圈层进行合理布局,这是新时期该地区进行产业结构调整与优化、制定产业发展政策及区域经济发展战略规划的重要任务.  相似文献   

20.
The dynamics and structure of the phytomass and production of an undisturbed mesotrophic dwarf shrub–sphagnum phytocenosis and one burned by fire have been compared. The net primary production (NPP) of both sites of phytocenoses in the postpyrogenic period is estimated by direct field determination of the productivity parameters, and C emission from the fire is assessed. The obtained data on emission (0.7 kg/m2) differ from the results obtained in the peatlands of western Canada (3.2 kg/m2).  相似文献   

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