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1.
The composition and structure of tree stands near the timberline have been studied on different slopes and at different elevations in the Tylaisko-Konzhakovsko-Serebryanskii Massif, the North Urals. It has been found that the upper limits of tree stands with different degrees of canopy closure have risen considerably (by about 100 m of elevation) since the mid-19th century, although the formation of these stands started as early as the late 18th century. Woodless areas in the eastern part of the massif started to be colonized by Larix sibirica in the late 18th to early 19th centuries; those in the western part, by Picea obovata in the mid-19th century; and in the southern part, by Betula tortuosa in the late 19th century. Analysis of meteorological data provides evidence for warming and increasing humidity of the climate since the late 19th century. Favorable climatic changes that facilitated the expansion of the forest have taken place both in the summer (prolongation of the growing period) and in winter seasons (increase of air temperature and precipitation). The observed differences in the composition and dynamics of tree stands between the studied areas of the mountain range are most probably explained by different requirements of tree species for the depth of snow cover and the degree of soil freezing.  相似文献   

2.
Variation in radial increments of 28-year-old Pinus sylvestris L. clones in response to changes in weather conditions during the period between 1986 and 2007 has been studied in the Sredneobskii Bor pine forest. Significant genotypic differences in the adaptive reaction norm of the clones have been revealed. It has been shown that the contribution of genotypic differences to the total variance of test characters is usually significant and depends both on the conditions of growing season and on a given increment character.  相似文献   

3.
Analysis of organic contaminants is reported for the Oluyoro stream located in the South-Western Nigeria. Using gas chromatography methods with flame ionization, electron capture and mass spectrometer detectors, alarming levels of organic pollutants including alkanes, alkenes, alcohols and alkyl halides were detected. Remarkably, toxic halogenated organic substances such as 4,4′-dichlorodiphenyltrichloroethane (4,4′-DDT), 4,4′-dichlorodiphenyldichloroethane (4,4′-DDD), beta-benzenehexachloride (beta-BHC), heptachlor epoxide, endrin aldehyde and endrin ketone are found to be at 15,820, 6,176, 1,155, 336, 24 and 13 times, respectively, more than the permitted levels of the United States Environmental Protection Agency (US-EPA). Furthermore, 4,4′-DDD, a probable human carcinogen, and methoxychlor are detected for the first time when compared to the last report published in 1992. Activities such as high influx of domestic and industrial wastes to the stream have drastically increased the concentrations of these halogenated contaminants. Results presented in this article provide important information for potential future effects of these contaminants on human health and the integrated environment in the region.  相似文献   

4.
随着全球化推进,各国开始不断消减贸易壁垒,环境规制程度跟着提升,各级地方政府作为环境规制相关政策执行者,国家的环境治理直接受到其环境规制策略影响。论文围绕地方政府恶性竞争导致的环境规制失灵问题,采用变截距GLS方法和Hansen提出的"门槛回归"模型,并利用我国29个省级单位2000-2013年面板数据,将地方政府竞争作为门槛变量,分析在不同门槛值下地方政府竞争、区域开放对工业环境规制的影响,并进一步研究财政收支分权和贸易政策对这种影响是否存在积极或恶化作用,力求从根本上解决地方政府恶性竞争,实现环境有效规制。研究表明:在样本期间内,财政收入分权度较低、财政支出分权度较高、贸易开放度高、金融开放度高和制度环境不完善的地区,地方政府竞争对工业环境规制的促进作用更加凸显。全国和东部地区地方政府竞争对工业环境规制呈边际递减的促进作用,中部地区表现出地方政府竞争对工业环境规制非单调性,西部地区存在对工业环境规制呈边际递减的抑制作用。总之,样本期间内地方政府竞争程度有助于全国和东部地区环境进行有效规制,中部地区跨越门槛值后环境规制失灵,西部地区则存在较严重环境规制失灵问题。为了规避环境规制失灵,我们应提高外商投资的进入环境门槛,地方政府在治理环境时,应削减对自己地区的行政垄断,推动各级地方政府跨区域环境保护合作,并由较高层级的政府来承担环境规制的财政支出责任,不断降低地方政府恶性竞争导致的环境规制失灵。  相似文献   

5.
工业是发展循环经济的关键领域,工业节能则是衡量循环经济发展水平的重要指标。不同的工业行业的能耗效率是不一样的,优化工业结构即增加能耗效率高的行业的比重而降低能耗效率低的行业的比重会产生一定的节能效果;提高工业行业的能耗效率能够产生明显的节能效果,而科技进步则是提高能耗效率的主要途径。循环经济的外部性原理说明,具有正外部性的经济活动因为私人收益小于社会收益,经济活动主体缺乏投资热情,这类经济活动会存在发展动力不足的现象。工业节能如果是存在正外部性的经济活动,则也会存在发展动力不足现象。工业节能的正外部性会表现在工业节能和工业的利润总额之间的关系上,即工业节能并不能促进工业利润总额的增长,两者甚至会有负相关关系。在上述论断的基础上,本研究分析中国工业结构变动的节能效果以及工业节能和工业利润总额的关系。方便起见,将工业节能的途径区分为结构调整节能和循环经济节能两类,分别探讨两类途径对中国工业节能的作用。依据循环经济与科技变革之间的关系,将工业行业分为A类循环经济行业和B类循环经济行业,并推断A类行业的节能量同利润总额存在相互促进的关系,B类则呈负相关,进而运用面板数据分析技术验证上述论断。如果工业节能具有正外部性,则B类循环经济行业应该明显多于A类。研究结果表明:从2006年至2013年,中国工业结构调整的节能效果非常微弱,中国工业节能主要是通过发展循环经济而取得的;循环经济具有正外部性,大多数行业的节能量与利润总额呈负相关关系;A类和B类工业行业循环经济发展水平和发展动力存在明显差异;科技进步在循环经济发展过程中发挥着决定性的作用。本研究建议,政府在推进工业节能工作的时候,应实施有差别的产业政策,相比于A类循环经济行业,对B类循环经济行业应给予更多政策优惠;提供循环经济补助资金和发展循环经济公共技术是提高工业节能效果的两大重要政策工具。  相似文献   

6.
Environment, Development and Sustainability - Sustainable supply chain emerges as a major business trend essential to long-term competitive advantage. Relevant corporate decisions concern a broad...  相似文献   

7.
Abstract

With the advancements in technology and increase in demand for eco-efficient products, manufacturers are focusing on sustainable development of products. Enticing a huge demand over the recent years, sustainable development of Information and Communication Technology (ICT) products are a subject of interest for most practitioners and academicians. A number of factors are found to influence the sustainable development of ICT products. It is necessary to identify the most important factors and determine the dependencies of factors among themselves. In this regard, a case study has been conducted in the context of sustainable development of tablet devices. The most influential factors have been identified from literature and with experts input. The factor dependencies are established using Total Interpretive Structural Modelling (TISM) methodology. MICMAC analysis is used to classify the factors based on their ability to influence other factors. The output of TISM forms the input for MICMAC analysis. From the study, it was found that the factors, ‘Customer pressure’, ‘Government regulations’, ‘Competitiveness’, ‘Organization initiative’ and ‘Technological advancements’ are the most driving factors. Factors ‘Environmental impact’, ‘Energy efficiency’ and ‘Opportunities to upgrade’ were found to be dependent.  相似文献   

8.
With the recommendation of the EU environmental policies, the separate waste collection issue has become more and more an object of public concern. Nevertheless, Italy’s waste management performances need further assessment processes. Until recently, some areas, especially in the South, have experienced serious waste management crises, mainly due to low rates of separate waste collection (less than 10 % of solid waste generated). The aim of this paper is to analyse the driving factors that influence the separate waste collection. Relatively to the Italian provinces in the year 2011, the analysis consists of two steps. In the first step, we characterize different institutional and socio-economic contexts through a multidimensional scaling analysis. In the second step, we provide evidence about the presence of subsets among Italian provinces using cluster analysis. Results show that contexts featuring high institutional quality promote the separate collection process. Differently, tourism-oriented environments characterized by low institutional quality don’t produce positive effects on the recycling process.  相似文献   

9.
This study employed a cross-country panel data model to investigate the relative contributions of sociopolitical, natural and cultural characteristics and national tourism policies to international tourism growth. International tourism receipt data were adjusted for country-specific inflation and then analyzed in relation to standardized measures of the World Economic Forum’s “pillars of tourism competitiveness.” Results indicated that international tourism receipts are more responsive to policies and regulations favoring tourism, abundance of natural resources, richness in cultural heritage, and health and hygiene than they are to infrastructure, safety, price competitiveness, and other variables. Findings highlight key factors associated with international tourism receipts and provide a general framework that could inform policies and management strategies designed to promote sustainable international tourism development.  相似文献   

10.
Environment, Development and Sustainability - The majority of data envelopment analysis (DEA) research studies evaluate the sustainability of processes with real-valued factors and individual role,...  相似文献   

11.
中间消耗的"消耗规模与部门构成"是影响中国出口碳排放的重要因素。基于世界投入产出数据库(WIOD)1995—2015年数据,在部门归类与形式变换基础上,本文选取"单位产出碳排放量"、"完全消耗系数"与"出口值"为中国出口隐含碳排放的影响因子,构建"因子变动—反事实构造—效果评价"分析框架,借助规模指数与结构指数对影响因子的变化动态进行描述,并通过反事实构造对"因子变动"的影响效果进行评价。研究发现:"单位产出碳排放量"规模指数单调递减,Spearman偏度系数为右偏态,说明相比于意愿产出而言,非意愿产出"碳排放量"具有内在的规模不经济;"中间消耗"规模指数与碳偏向性指数在截面上始终处于高位水平,时序上出现了显著的递增趋势,说明中国单位出口值的中间消耗量偏大,消耗投入在结构上偏向于高碳部门,与"技术前沿国"美国存在显著"技术差距";"出口值"规模指数呈现"平缓扩张——快速攀升——V型震荡"的阶段性特征,结构指数经历了以基期2002年为顶点、"先下降、后上升、再平稳"的变化轨迹,说明"出口值"作为最具弹性的影响因子,受"亚洲金融危机"、"加入世界贸易组织"与"美国次债危机"等外部冲击的影响明显,对出口碳排放的推动作用存在伸缩性与阶段性差异。从"因子变动"影响效果来看,中国产出、中间消耗与出口的部门构成具有内生关联,均显著偏向于高碳部门,对出口隐含碳排放增长产生了叠加性的"正向"扩张效应。基于此,本文认为,总量控制与结构优化的视角需从产品环节向中间消耗环节扩展,现阶段应深化要素市场改革,加速要素禀赋升级,借力要素价格机制与差别化产业规制政策,从上游环节抑制出口碳排放的输入来源。  相似文献   

12.
This paper has developed a two-sector model of forestry that gives some insights into the interactions of poverty, land tenure insecurity, economic growth, trade and deforestation in the context of the drylands of Africa. Externally, the model results show that the world demand for non-timber forestry products can lead to a win-win situation whereby both trade and environmental sustainability can be promoted. Monopolistic measures to control the supply of these products, for short-term price gains, are harmful economically and environmentally. By contrast, productivity-raising measures have a favourable impact on both the economy and the environment. Internally, the model results show that the growth of the rest of the economy has driven the economic growth of the forestry sector, but at the same time, its environmental degradation. Poverty and land tenure insecurity also contribute to this degradation. Fortunately, policies promoting basic needs satisfaction and property rights security are shown to be effective in mitigating environmental degradation in the forestry sector. The paper results contribute towards a more sustainable exploitation of forestry.Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue.  相似文献   

13.
This paper has developed a two-sector model of forestry that gives some insights into the interactions of poverty, land tenure insecurity, economic growth, trade and deforestation in the context of the drylands of Africa. Externally, the model results show that the world demand for non-timber forestry products can lead to a win-win situation whereby both trade and environmental sustainability can be promoted. Monopolistic measures to control the supply of these products, for short-term price gains, are harmful economically and environmentally. By contrast, productivity-raising measures have a favourable impact on both the economy and the environment. Internally, the model results show that the growth of the rest of the economy has driven the economic growth of the forestry sector, but at the same time, its environmental degradation. Poverty and land tenure insecurity also contribute to this degradation. Fortunately, policies promoting basic needs satisfaction and property rights security are shown to be effective in mitigating environmental degradation in the forestry sector. The paper results contribute towards a more sustainable exploitation of forestry.  相似文献   

14.
Leaders of the PAGES Focus 5 programme ‘Past Ecosystem Processes and Human–Environment Interactions’ identify key issues for research on human–environment interactions for wider discussion. These include the need for long-term perspectives, the opportunities for maximising palaeoenvironmental research, the need for integration and regionalisation and the challenge of developing dynamic simulation models. A new organisational matrix for regional studies is outlined, based on a series of zonal/azonal regions and on the degree of human impact. Future priorities for palaeoenvironmental research include new studies in degraded human-dominated landscapes, highly-valued ecosystems and sites relevant to other IGBP Core Projects. Simulation of future human–environment interactions using modelling approaches that have been tested against long records lags behind global climate modelling, but cellular approaches for biogeophysical and multi-agent systems show promise.  相似文献   

15.
无论是古典经济学理论、社会契约理论还是利益相关者理论,似乎都缺乏了一个重要的元素:政府行为以及政治、经济体制的影响,而只是将政府作为一个仅仅取得税收收益的利益相关者纳入我们的分析范畴,忽视了不同政治体制下政府构成了企业生存重要环境的特殊事实,这样的淡化直接影响我们对企业社会责任行为的实然理解。根植于西方社会的传统企业社会责任理论没有过多的考虑政府行为以及政治体制的影响,是基于其自身的制度背景与社会文化,它们是以高度自由的市场经济为基础,政府对经济(企业行为)干预很少,整个政治经济制度更加贴切新古典经济学的假设。而以中国为代表的新兴市场国家,政治经济体制改革和经济转轨使得制度环境对经济运行和企业决策有着重要影响,这为政治经济学理论的运用提供了制度基础,也为从政治经济学角度分析公司社会责任行为提供了研究机会。本文以我国2004年-2011年沪深股市的上市公司为研究样本,基于新政治经济学的寻租理论,研究了我国企业社会责任行为的寻租动机。研究的结果发现:我国企业社会责任行为呈现出明显的寻租倾向,而由于受到二元经济体制割裂的影响,相对于国有企业具有产权联系的先天优势,非国有企业社会责任行为表现出更为强烈的政治寻租倾向。实证研究同时也表明,产品市场竞争越激烈,企业寻租倾向越强。论文的研究构建了我国企业社会责任行为新的分析性框架,拓展了企业社会责任行为研究的相关文献。  相似文献   

16.
在中国经济高增长的背后,环境污染问题愈发凸显,不利于经济的可持续增长。税收竞争是影响环境污染的主要因素之一,但是学术界研究税收竞争对环境污染的影响及其作用机制的较少。本文按照污染物属性将其划分为外溢性污染物和非外溢性污染物,通过构建一个包含生产者、消费者、地方政府及中央政府的一般均衡模型,刻画了在税收竞争的背景下,地方政府的税收征管效率对不同属性污染物的影响及其传导机制。结果发现当污染物具有外溢性属性时,税收征管效率对该地环境污染的影响通过改变本地及周边地区资本存量渠道实现;当污染物具有非外溢性属性时,降低税收征管效率通过增加该地区资本存量而提高了环境污染。文章首先使用随机前沿模型测算了2007—2014年中国28个省份企业所得税的税收征管效率,并将其作为税收竞争的衡量指标,然后运用系统GMM法证实了所提的假说。研究显示:地方政府的税收竞争增加了本地区的资本存量;税收竞争是将本地资本存量作为其推高外溢性污染物(二氧化硫)及非外溢性污染物(固体废弃物)排放量的一个主要渠道,邻近地区资本存量则是推高外溢性污染物(二氧化硫)的次要渠道。这意味着,要想改善环境质量,中央政府应规范地方政府的税收竞争行为,尽快建立一套科学、有效的绿色GDP评价体系;完善地方转移支付制度;应针对各个地区的污染及经济发展情况利用财政激励手段引入环保、绿色的资本项目;地方政府应减少不利于环境改善的地方财政支出,增加环保投入比重。  相似文献   

17.
Sources of variation in the relative spleen weight have been studied in small mammals (Rodentia: Muridae, Cricetidae; Insectivora: Soricidae) from the Ural and Fennoscandian forest ecosystems differing in the level of industrial pollution (2004?C2010). Formal threshold indices for the diagnosis of splenomegaly in rodents and shrews have been proposed and substantiated. Effects of several factors on the probability of splenomegaly have been estimated, and the ??normal spleen?? index has been determined.  相似文献   

18.
Natural resource degradation in highland regions is of increasing concern to the global community due to its role in aggravating poverty and the loss of environmental services to local and downstream users. The integration of trees into smallholder farming systems has been promoted as a means to enhance rural livelihoods while reversing the degradation of soil, water, biodiversity and related environmental services. Yet in addition to these benefits, negative impacts of trees on certain stakeholders or system components have also accompanied such efforts—suggesting that important trade-offs accompany afforestation. This paper presents a methodology for diagnosing problems stemming from cultivation of certain tree species in specific landscape niches. Data derived from the application of this methodology in two sites in the eastern African highlands are presented. Participatory diagnoses of landscape-level problems suggest that the negative impact of trees on water resource availability and crop yield are of critical concern to smallholder farmers. Ethnoecological data highlight the properties of different tree species that determine their suitability to specific farm and landscape niches. These data point to important opportunities for more socially- and environmentally-optimal integration of indigenous and exotic tree species into agricultural landscapes, and highlight the critical importance of local knowledge in forging solutions appropriate to contemporary realities.  相似文献   

19.
The aim of this study was to determine the possible effects of meteorological factors on the crown condition of Norway spruce in habitats with different site humidity. In many cases the correlation between meteorological indices and crown condition was stronger and more reliable in habitats with normal humidity than in overmoist habitats. Our results suggest that meteorological conditions during the vegetation period play more significant role compared with dormant period for spruce crown condition.  相似文献   

20.
江苏省高资源消耗型产业甄别与竞争力评价研究   总被引:1,自引:0,他引:1  
江苏省高资源消耗型产业经营模式粗放。行业产值贡献份额小,资源占用份额大。经济发展和人口、资源、环境的矛盾十分突出,因此。高资源消耗型产业的甄别与合理调控是江苏建设节约型社会的关键。本文采用了资源消耗指数法甄别出江苏省12种高资源消耗型产业。研究表明:高资源消耗型产业在江苏省工业中占据绝对的比倒优势。有些产业甚至是江苏省经济发展的主要支柱产业:针对江苏高资源消耗型产业发展的特点。从经济实力、资本实力、对外开放水平和资源节约实力4个方面构建了产业竞争力评价指标体系。采用因子分析法对高资源消耗型产业的综合竞争力进行了评价。研究结果表明,除化学原料及化学制品制造韭、纺织韭和电力、燃气及水的生产供应韭竞争力较强外。其他类别的高资源消耗型产业的综合竞争力普遍偏低;最后从产业发展结构调整、重点行韭发展规划和行韭管理优化3个方面对江苏高资源消耗产韭的可持续发展提出调控策略。  相似文献   

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