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1.
It is well known that the structure of leaves plays an important role in adaptation, but there are still no accurate structural criteria to indicate ecological characteristics of the species. We have studied parameters of leaves in 100 herbaceous plant species growing in the southern taiga subzone that belong to different ecological groups in relation to irradiance and moisture supply. The results show that leaf area, thickness, and anatomical type are less correlated with ecological characteristics of the species than structural parameters of photosynthetic tissues. In the series shade-loving mesophytes—light-loving hygromesophytes—mesophytes—xeromesophytes—mesoxerophytes, the concentration of cells and chloroplasts in the leaf gradually increases by a factor of up to 7–10, their size decreases two-to threefold, and the ratio of mesophyll surface area to leaf surface area increases fourto fivefold. It is concluded that characteristics of mesophyll are of adaptive significance. A system of characters is proposed for identification of ecological groups of plants growing in the boreal zone.  相似文献   

2.
In this research a closed loop supply chain is designed which incorporates reverse logistics and forward logistic system simultaneously. In the design of reverse logistic system, recovery options are embedded in traditional supply chain for treating returned products. The recovery system includes collection centres, remanufacturing plants and disposal centres. Since the product return is supply driven, there is an uncertainty about it. In the proposed configuration for closed loop supply chain, the optimised configuration for supply chain in terms of locating recovery plants is developed. Accordingly, a fuzzy mixed integer linear programming model develops to deal with the uncertainty of returning products by customers. A general-purpose solver (LINGO 8.0) and a Meta heuristic approach (genetics algorithm) are implemented to solve the proposed model. The answers are compared by defining indexes and then the optimal answer, configuration and variables are identified. This solution will suggest a new design of supply chain network in which waste of materials is minimised and the new raw materials are necessary only when the used products may not be recovered by recovery options.  相似文献   

3.
Sustainability science is a new branch of human knowledge. It is necessary to model sustainability science based on a framework consisting of the interactions of society, ecology, the environment and the economy. This paper develops such a model, the SEEOSG model, containing the essential structural relationships that incorporate the environmental and economic conditions required for sustainability. The model is solved as a dynamic optimisation problem. This optimal growth model of ecology and economic growth enables us also to analyse the issues which are specific to sustainability science such as the ecologically sustainability and inter-generational equity implications of economic activities and policies. In the model results growth maximisation goals appear to be fraught with difficulties such as infeasibility and non-sustainability. The results also suggest also that an equilibrium ecological and economic system does not sustain over a very long period of time unless appropriate actions are taken. Readers should send thier comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue.  相似文献   

4.
针对水利枢纽施工过程中对周边环境的干扰机制,提出生态系统综合评价指标体系,利用RBF神经网络建立水利枢纽施工干扰区生态系统综合评价模型,并以尼尔基水利枢纽为例,对其施工干扰区生态系统进行综合评价。评价结果表明各指标在施工期间均跌到最低点,其中受影响最大的就是社会进步指标和景观生态性指标。但是在恢复过程中,这两类指标的上升幅度也是最大的,自然生态环境具有较强的稳定性,但当外界干扰超过其自身的承受能力时,对其进行恢复的难度也是很大的。可见,RBF生态评价模型可以对施工干扰区生态现状进行评价,评价结果为干扰后的生态环境恢复与重建提供理论依据,也可对治理后的效果进行预测评价,并为其他水利枢纽工程施工干扰区生态恢复与重建提供科学借鉴。  相似文献   

5.
基于灾变理论的盐城市土地生态安全评价研究   总被引:1,自引:0,他引:1  
土地生态安全关系到区域的可续发展。以压力 状态 响应模型与灾变理论相结合,根据盐城市的土地利用特点,分别从社会、经济和生态环境方面构建土地生态安全评价指标体系,分析盐城市2002~2011年的土地生态安全变化情况,找出其中的问题,能为盐城市土地利用可持续发展提供理论依据和参考价值。研究表明:盐城市土地利用生态安全等级除了2003年和2007年为安全等级外,其余8 a均为中等安全、不安全和极不安全等级,而且基本呈逐年下降趋势;人口、环保投入和城镇化是导致盐城市土地利用生态安全等级下降的重要影响因素,这种现实状况应该引起政府相关决策部门的高度重视,最后提出了几点建议  相似文献   

6.
Abstract

Increasing populations are causing an increase in food demands, and the area of cultivated land expands every year. Inappropriate land transition from ecology to production results in the constant decline of the ecological security level and influences the regional sustainable development. Adjusting unreasonable land use mode and reconstructing natural land cover are important ways to maintain and improve the ecological environment. Also reclaiming farmland as areas for forests and grasslands (FRFG) is another way. Successful implementation of FRFG in China is the result of comprehensive effect of the multi-scales driving forces. This paper analyses the driving forces of FRFG in China on a national (country)—regional (province)—local (county)—household (farmer) level scale, and the results are: driving forces at the national scale include ecological and food security and the western development of China; at the regional scale, ecological and economic benefits become the main factors to influence the dimension of FRFG under the same policy. The driving forces can be divided into 6 types: industrial structure adjustment, water source protection, flood prevention, the Three-Gorge Project protection, reduction of the amount of sediment flowing into the Yellow River and wind erosion desertification prevention. The driving forces at the local scale can be divided into 12 types with developing leading industries, increasing farmers' income and improving agricultural production conditions as the main types; at the household scale, the national policy meeting farmers' demands and the optimization of individual interests are all driving forces.  相似文献   

7.
20世纪90年代以来,生态足迹模型作为定量化可持续评价的重要理论方法得到了广泛的应用。基于传统生态足迹模型,结合遥感产品净初级生产力数据,构建了基于净初级生产力的生态足迹模型,调整了均衡因子和产量因子,并增加了污染物账户。在此基础上,应用传统模型和改进后的模型分别计算了南通市2000~2013年的生态足迹。结果表明:(1)传统生态足迹模型和改进模型下的南通市2000~2013年人均生态足迹都是稳步增长的,改进后的模型变化较小;(2)南通市2000~2013年生态承载力虽有所波动,但整体上呈下降趋势;(3)南通市连续14年出现生态赤字,从2000年的0.308 6 hm~2/人上升到0.587 7 hm~2/人,生态系统处于不安全状态,生态系统的稳定性降低。可见,改进的生态足迹模型能更准确地反映研究区自然资源利用状况。最后,针对南通市生态不安全状况,从土地结构、能源消费等方面提出减少生态足迹的建议。  相似文献   

8.
The first part presents a conceptual model of the economic system in its ecological and social context. It is developed via an integration of basic concepts in physical resource theory, animal and human physiology, economic theory and systems ecology. The capacity of the model to support analysis of such complex systems where life is a key system characteristic is high. The conceptual model shows the dependency of the human economy on support by non-renewable and renewable resources from Nature (i.e. ecological source restrictions), as well as the capacity of ecosystems to assimilate wastes (ecological sink restrictions). The analysis focuses general principles; thus, the high level of abstraction results in an apparent simplicity. In the second part, we integrate traditional economic production functions and the conceptual model, which results in the formulation of a biophysically anchored production function (BAPF). The BAPF by itself, and through the system of ecological economic accounts that can be derived from it, represent a toolbox that supports the operationalisation of a sustainable development from micro to macro level. It is coherent with Impredicative Loop Analysis, existing management systems within agricultural sciences, OECD’s principles for sustainable development and the approach of Millennium Ecosystem Assessment. Compared to analytical approaches used in the formulation of sustainability policies in the private and public sphere, based on conceptual models ignoring the complexity when life (bios) is a defining system characteristic, its relevance for the operationalisation of sustainable development approaches infinity. The third part presents results from statistical analysis of relations between gross domestic product and energy supply and some emissions, respectively, for different nations and time periods, delivering values on levels and trends for parameters in the BAPF as well as a first test of the relevance of the BAPF proposed. The paper is ended by a theoretical analysis of the costs of provoking an economic system working under ecological source and sink restrictions to follow exponential growth: The need to decouple economic growth from natural resource use and emissions is highlighted. Otherwise, the erosion of the ecological foundation of the economy with regard to source as well as sink aspects will be a function of exponential growth.  相似文献   

9.
生态文明建设的关键因素识别   总被引:1,自引:0,他引:1  
生态文明建设是共创民族伟业、中国圆梦的时代重任,提高生态文明建设水平需要对生态文明建设的关键因素进行分析识别。本文从生态文明意识、生态文明制度和生态文明行为三个方面建立生态文明建设影响因素指标体系,选取全国31个省份2012至2014年的相关数据,运用BP神经网络法降低DEMATEL模型中专家打分建立关联矩阵的主观性,结合摆幅置权法(SW)得出综合重要度,遴选出生态文明建设关键因素。其中,年份最近的2014年计算得出的关键因素按照重要度排序依次为:本级环保能力建设资金使用总额、排污费解缴入库户金额、机动车污染物排放总颗粒物、网站主动公开各类政府环境信息条数和环保系统人员总数。将这些因素按照生态文明的基本内涵划分为三大类,得到3点结论:生态意识虽不起决定性作用,但能强化整个社会的生态文明建设的思想和理念,生态文明意识所占的比例先降后升,不断提高;随着生态文明建设理论和实践经验的丰富,逐渐感受到成熟的制度设计、明确的制度规范才是根本,生态文明制度类别在关键因素中所占的比例越来越高;生态文明行为作为表现形式,随着其他两方面的变化,生态文明行为不断改善,在生态文明建设的关键因素中所占比例下降。本文在生态文明意识方面提出要针对性地帮助和鼓励各级环保部门开展信息公开工作;在生态文明制度方面提出强化环保能力建设资金的监管力度,发挥排污费的真正作用,提升环保系统人员的能力素养,探索新工作思路等举措;在生态文明行为方面提出综合车、油、路等多方面措施防治机动车排放污染等建议。  相似文献   

10.
研究生态文明指标及其权重对客观科学评价生态文明具有重要理论与实践指导意义。为解决生态文明指标及其权重研究的不足,创建了压力(Pressure)-状态(State)-影响(Impact)-响应(Response)与结构方程模型(Structural Equation Modeling)相结合的方法,利用中国及31省域2007~2016年动态面板数据来优化筛选生态文明指标和计量其权重,并将PSIR SEM、熵权法、AHP法算得的指标权重进行比较以揭示PSIR SEM方法在指标选取和权重计量的特性。研究表明:(1)生态文明指标包括社会产业经济(8指标)、资源环境(9指标)、生态效益(7指标)、生态文明响应(10指标)4方面且相互发生关系,并强化了生态、注重生态文明响应,弱化了产业经济,较已有未考虑生态文明响应、注重经济而非生态等更合理;(2)生态文明指标权重为生态文明响应(0.292 9)、生态效益(0.250 3)、社会产业经济(0.239 3)、资源环境(0.225 3),生态指标与产业经济指标权重差距不大,更能全面反映生态文明产业与生态共生的本质属性;(3)31省域中,处于生态文明阶段的省域数量(14省域,占比45.16%)要少于处于非生态文明阶段的省域数量(17省域,占比54.84%),较已有“无论区域是否处于生态文明阶段,均采取‘一刀切’地对其生态文明评价”等更合理  相似文献   

11.
甘南黄河水源补给区生态补偿农户参与意愿分析   总被引:2,自引:0,他引:2  
生态补偿是非常有效的解决世界生态问题的政策工具集,农户作为生态补偿项目的实施主体,其参与意愿直接影响生态补偿项目的实施绩效和可持续性。甘南黄河水源补给区承担重要的生态服务功能,属国家级限制开发区,自2003年开始,实施退牧还草等生态工程。在此背景下,通过实地调研,运用二项Logistic模型进行分析,得出以下结论:①甘南黄河水源补给区农牧民对生态补偿项目的认知水平很低,主要是客观条件限制和政府宣传力度不足所致;②受生产方式的影响,甘南黄河水源补给区内,农区农户的生态补偿参与意愿强于半农半牧区、纯牧区;③对甘南黄河水源补给区农户生态补偿参与意愿影响最显著因素是农户对现行退牧还草政策的满意度,其次为农户家庭年收入、牲畜存栏数、退牧还草政策实施后的收入变化及其对生态补偿项目的支持度,再次为农牧民对生态补偿的了解度及其环境意识。基于此,提出了进一步完善生态补偿政策、提高农户参与意愿的措施,为进一步完善生态补偿机制提供借鉴。  相似文献   

12.
为进一步了解水电开发对河流健康的影响,本文以雅砻江下游水电梯级开发为例,构建河流健康评价指标体系,选择无人为干扰和干扰较小的河流为参照,以指标变化率衡量水电梯级开发前后河流受扰动程度,分别采用综合评价法和赋值评分法进行了定量评价。综合评价结果显示,雅砻江下游河段的综合健康指数为0.71,该研究区域在丰水期、平水期和枯水期的综合健康指数分别为0.74、0.70和0.69,均处于亚健康状态;赋值评分法结果显示建库前的河流健康指数(River health index,RHI)为19.1,等级为健康,建库后为14.3,等级为亚健康,两种方法评价结果基本一致。本文以期完善河流健康评价体系,并为生态修复提供依据。  相似文献   

13.
The general concept, structure, and methods of implementation of the ECOINFORM information retrieval system (IRS) (http://ecoinf.uran.ru/) are described using the Urals and western Siberia as model regions. The IRS is aimed at ensuring effective access to the latest information in various fields of theoretical and applied ecology, overcoming the informational isolation of research centers and state reserves in remote regions, coordinating and intensifying joint ecological studies, and integrating the fundamental science and higher-education institutions.  相似文献   

14.
我国生态功能区划的目标、原则与体系   总被引:32,自引:2,他引:32  
阐述了我国开展生态功能区划的背景,分析了全国生态功能区划的基本目标和任务。以生态系统科学为基础,明确了开展生态功能区划的基本原则——生态系统完整性原则。在生态系统完整性原则下。定义系统、系统边界、系统等级和认识生态系统的尺度。对生态功能区划与自然区划、农业区划以及生态地域划分之间的联系与区别进行了分析,指出从单一要素的各种自然区划,到以整体生态系统为基础的生态功能区划是协调人与自然关系、寻求自然资源保护与人类对资源的永续利用之间的平衡的认识进步。在生态系统完整性原则上,提出了我国生态功能区划体系的框架。论述了流域在生态和社会经济方面的重要性。认为以大流域为基本区划单元的划分是构建我国生态功能区划的基本方式.“生态热点”地区规划是必要的、灵活的辅助手段.  相似文献   

15.
拟破解生态文明测度和评价的现存难题:在指标选取方面,评价目标模糊,指标筛选的主观性强,缺乏结构化方法,导致指标泛化,与一般环境经济评价混淆;在测度标尺方面,无法确定生态文明阈值,对不同文明阶段用同一把尺子去衡量,导致一些非生态文明区域的排名反而靠前;在应用价值方面,综合指标值失去生态经济意义,只是一个抽象的排名数字,导致测度结果不便于理解和运用。为此,依据文明演化的共生理论创立指标-指数耦合链方法,用以导出生态文明测度的阈值和绿值二步指数。依次运用扎根理论法、PSIR及SEM结构模型、足迹家族法、Lotka-Volterra模型等工具,构建从生态文明的指标体系到二步指数的结构化耦合链。全过程始终聚焦生态文明的本质属性——产业与生态的互利共生性:以定性科学属性为出发点,以人与自然复合系统的结构模型为纽带,以生态文明阈值和绿值二步指数定量模型为归宿点。其中,阈值用产业受力指数、生态受力指数和共生度指数3项指数进行衡量,合称为阈值指数;而绿值用1项综合反映区域产业与生态的总量、共生程度和均衡程度的绿值指数进行衡量。据此进行区域生态文明的二步测度。第一步,基于阈值指数的阶段或资格判定:通过产业与生态的共生性,考量被测区域是否进入生态文明门槛,"未入门"区域处于哪一个文明阶段。第二步,基于绿值指数的水平判定:通过产业与生态的互利共生程度,考量"入门"区域的生态文明水平。研究表明,指标-指数耦合链方法不仅可以有效克服单纯指标体系综合法或指数函数法的缺陷和难点,而且能够将两者的长处结合起来。如此,不仅能够避免生态文明测度结果与物质文明"成正比"的弊端,而且能够通过从生态文明二步指数回溯至指标体系的逆向解耦,分析出导致生态文明问题的根本原因,便于提出切中肯綮的对策。  相似文献   

16.
生态安全评价是建立生态安全预警系统及进行环境管理的基础。为确立有效的区域生态安全评价方法,基于压力-状态-响应概念模型,构建了区域生态安全评价指标体系和评价标准;采用BP神经网络的途径,对安徽省17个地级市的生态安全评价问题进行了研究。结果表明:宣城、池州、黄山为Ⅱ级,亳州、宿州、阜阳、滁州、六安、巢湖、安庆为Ⅲ级,合肥、淮北、蚌埠为IV级,淮南、马鞍山、芜湖、铜陵为Ⅴ级。区域生态安全的BP神经网络评价方法涵义明确,计算过程简单,能区分生态安全的等级,可以应用于具有评价标准的其它生态系统综合评价。  相似文献   

17.
以乐山市土地利用总体规划为研究对象,应用相对风险模型(Relative Risk Model,RRM),对其生态风险进行了分析和评价。评价结果表明,在规划执行期间,全市生态风险总体呈下降趋势,但在区域内的空间分布上却具有不平衡性,局部地区的生态环境会出现波动甚至恶化;作物种植、交通运输和人口负荷是规划生态风险的3个最主要来源;而林地和牧草地在所有生境类型中所受到的生态压力最大;对于生态风险结果,主要表现为区域生态系统及其组分在功能与结构上的损害。研究结果能够为乐山市土地资源开发利用和规划成果的科学决策提供理论依据,同时具有开展区域生态风险防控与管理的参考价值。  相似文献   

18.
19.
Technological innovation and shorter product life cycles of electrical and electronic equipment coupled with their rapidly growing applications have resulted in the generation of an enormous amount of waste from electrical and electronic equipment (WEEE). To address the potential environmental problems that could stem from improper end‐of‐life management of WEEE, many countries have drafted national legislation to improve the reuse, remanufacture and material recycling from WEEE, and to reduce the amount of such waste going to landfills. With the introduction of such legislation comes an increased need for the recovery operators to evaluate the recycling costs and environmental benefits of reclaimed products and materials in order to select the most appropriate end‐of‐life options for individual products in WEEE. This paper presents a systematic methodology for ecological and economical assessment to provide a holistic understanding of the impacts associated with different end‐of‐life options for such waste. This assessment, in addition to providing decision‐support for the selection of the best possible end‐of‐life option for a particular product in WEEE, could also generate vital information to support the design and material selection processes during the initial product development activities. The assertion made is that the detailed considerations of the ecological and economical impacts associated with different end‐of‐life options will significantly improve the recovery and recycling of WEEE.  相似文献   

20.
中国环保行政体制结构初探   总被引:1,自引:0,他引:1  
环保行政体制结构是环保行政组织系统的基本框架,是实现环保行政管理职能的组织方式。我国长期以来的环保行政体制改革较为关注机构地位提升与管理职能强化,环保行政体制的结构较少得到关注。对环保行政体制结构的分析揭示了在机构地位提升与管理职能得到强化的前提下我国环保行政管理依然面临执法监督难、部门协调难等问难题的深层体制原因。本文首先根据组织行为学的基本原理,提出我国环保行政体制的矩阵结构模式,这一矩阵结构在纵向上存在双权威系统,横向上协调关系较为薄弱,从而造成环保监管权威弱化。其次,基于对我国地方环保行政体制改革效果的调查,指出我国环保行政体制结构出的了若干变化。最后,结合我国"十二五"时期落实国家环保意志的基本要求,提出改善我国环保行政体制结构的若干政策建议,即在基层改善体制结构中的双权威系统,并以流域水环境管理体制创新为大部门体制改革突破点,探索环境管理职能组织方式的优化途径。  相似文献   

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