Ecological effects of coastal marsh impoundments: A review

Many coastal resource managers believe estuarine marshes are critically important to estuarine fish and shellfish, not only because of the habitat present for juvenile stages, but also because of the export of detritus and plant nutrients that are consumed in the estuary. Concern has been widely expressed that diking and flooding marshes (impounding) for mosquito control and waterfowl management interferes with these values of marshes. Major changes caused by impoundment include an increase in water level, a decrease in salinity, and a decrease in the exchange of marsh water with estuarine water. Alteration of species composition is dramatic after impoundment. Changes in overall production and transport phenomena, however—and the consequences of these changes— may not be as great in some cases as the concern about these has implied. Although few data are available, a more important concern may be the reduction of access by estuarine fish and shellfish to the abundant foods and cover available in many natural, as well as impounded, marshes. Perhaps even more important is the occasional removal of free access to open water when conditions become unfavorable in impounded marsh that is periodically opened and closed. Collection of comparative data on the estuarine animal use of various configurations of natural and impounded marshes by estuarine animals should lead to improved management of both impounded and unimpounded marshes.     

正确认识绿色贸易壁垒

绿色贸易壁垒能促进广大发展中国家不断提高产品的环境保护水平,保护本国的生态环境,但在环保大潮的冲击下,一些贸易企业会由于产品不符合要求而面临出口困境。本文以绿色贸易壁垒产生的原因及应采取的措施等方面进行论述,指出绿色贸易壁垒既是挑战又是机遇,要正确认识绿色贸易壁垒。     

Ecological effects after an alum treatment in Spring Lake, Michigan

A whole-lake alum treatment was applied to eutrophic Spring Lake during October and November 2005. Eight months later, an ecological assessment of the lake was performed and compared with data collected in 2003 and 2004. Field measurements showed reduced soluble reactive phosphorus (SRP) and total phosphorus (TP) concentrations in the water column the summer after the alum application, but chlorophyll levels and irradiance profiles were not significantly affected. Total macroinvertebrate density declined significantly in 2006 compared with 2004, with chaoborids and oligochaetes experiencing the greatest reductions. Internal phosphorus release rates, measured using sediment cores incubated in the laboratory, ranged from -0.052 to 0.877 mg TP m(-2) d(-1) under anaerobic conditions. These internal loading rates were significantly lower than those measured in 2003 at three out of four sites. Mean porewater SRP concentrations were lower in 2006 than in 2003, but this difference was statistically significant only under aerobic conditions. The NaOH-extractable SRP fraction in the sediment was also significantly lower in 2006 compared with 2003, whereas the HCl-extractable SRP sediment fraction showed the opposite pattern. Overall, these results indicate that the alum treatment effectively reduced internal P loading in Spring Lake. However, water column phosphorus concentrations remain high in this system, presumably due to high external loading levels, and may account for the high chlorophyll levels. An integrated watershed management approach that includes reducing internal and external inputs of P is necessary to address the cultural eutrophication of Spring Lake.     

生态保护是建设生态文明的重要基础

十七大提出建设生态文明的奋斗目标,具有极其重大的意义.生态保护在建设生态文明中具有保护生存条件、保障生态安全、保护自然资源及生产力、保障可持续发展、促进生态文明观念在全社会牢固树立等重要作用.因此,生态保护是建设生态文明的物质基础、实现生态现代化的前提、建设生态道德的重要载体.     

Environmental regulation through trade: the case of shrimp

The implications of a potential ban on shrimp imports by the US from countries that do not utilize the Turtle Excluder Device on commercial shrimp nets is explored in this paper. A Linear Expenditure System (LES) was used to determine the own-price elasticities of demand for shrimp imports. The system of estimated equations was then solved for quantity levels under assumptions made about the trade restrictions, resulting in a set of prices for those import levels. These estimated prices were then used to estimate the compensating variation impact of the trade restrictions. Findings suggest that the environmental regulation would have a negative impact on US consumers, but the magnitude of that effect depends on assumptions made regarding the distribution of US imports after the trade restriction is imposed.     

Seaborne iron ore trade in the 1990s

This paper discusses how world steel production and seaborne iron ore trade have grown since 1950. The role of steel production forecasts in determining investment in the iron ore industry is examined. Forecasts for world steel production and the demand and supply of seaborne iron ore in the 1990s are presented. It is predicted that world steel production will increase by 64 million tons between 1991 and 2000. This increase will be located principally in the developing countries and China. The corresponding increase in seaborne iron ore trade will be approximately 55 million tons. Expansion projects will be located mainly in Australia and Brazil, but no greenfield iron ore projects will be undertaken. By the end of the decade, the demand for seaborne iron ore will be equal to its supply.     

Emerging market patterns in the recycled paper trade

The international recovered paper trade serves two important functions: increasing raw material availability in the paper and board industry and providing economic incentives to recycle. The purpose of this paper is to shed further light on emerging patterns in this trade by empirically analysing the changes in the bilateral trade flows of recycled paper between 1992 and 2008. According to our estimations, two important changes occurred in the 1990s and 2000s. First, the growing importance of developing economies in global recycled paper trade plays a significant role in import demand as a determinant of trade flows. Second, the changes in global trade patterns necessitate investigating the transportation cost measures used in applied research.     

Ecological effects monitoring in environmental impact assessment: What can it accomplish?

The premise that, strictly speaking, impact monitoring is impossible, is presented and discussed It is shown that a wide range of published objectives for environmental effects monitoring can be seen as special cases of the basic goal of reducing uncertainty in predictions. Monitoring in environmental-impact situations can only be used as a check on one of the two time series required to define impact. Four approaches to generating the other time series required in the difference calculation of impact are discussed, with the conclusion that the best approach relies on process-based simulation models. Impact analysts are encouraged to consider carefully what can and cannot actually be accomplished with environmental monitoring to assist impact detection.     

To trade or not to trade: Firm-level analysis of emissions trading in Santiago,Chile

Whether tradable permits are appropriate for use in transition and developing economies—given special social and cultural circumstances, such as the lack of institutions and lack of expertise with market-based policies—is much debated. We conducted interviews and surveyed a sample of firms subject to emissions trading programs in Santiago, Chile, one of the first cities outside the OECD that has implemented such trading. The information gathered allows us to study what factors affect the performance of the trading programs in practice and the challenges and advantages of applying tradable permits in less developed countries.     

城市生态保护红线与生态控制线协调性研究

生态保护红线与生态控制线是生态空间保护的两条主线,两线既有差别又紧密联系。生态保护红线是维护区域和城市生态安全的格局和数量底线,生态控制线是控制城市开发边界和保障生态安全划定的生态用地控制线。地市是两线划定的适宜尺度,本文在总结高、中、低不同开发强度城市两线探索实践的基础上,从两线联系与差异角度进行协调必要性分析。两线在概念内涵、法律地位、划定内容、技术方法、管控要求上的差异既是衔接的重点又是衔接的难点。然后,从空间、内容与管控等角度提出两线协调的思路,空间协调解决工作底图不统一、话语权不对等问题,内容协调解决生态用地保护目标不一致问题,管控协调解决部门管理准入条件不一致问题。最后,从工作机制角度,提出促进两线衔接的若干建议以及未来两线重点完善的内容和主要方向,为地市开展相关工作提供参考。     

牢固树立生态文明观念提升社会生态文明水平

党的十七大报告提出“建设生态文明”,并强调要使“生态文明观念在全社会牢固树立”。如何在全社会牢固树立生态文明观念,是需要我们认真思考的重要问题。本文试就全社会牢固树立生态文明观念的路径选择作一些尝试性的探讨。     

An economic analysis of the stability of East-West mineral trade patterns

This paper explains the nature and variability of East-West mineral trade patterns for manganese, chromite, phosphate and potash. This variability is assessed inherently as well as in relation to underlying causal factors. The impact of these factors is analysed in terms of their sources: domestic cost conditions, changes in economic activity, currency and dollar exchange requirements, trade controls, balanced payments needs, technological change and political goals. Results point to the importance of basic mineral needs in Eastern Europe and the rising costs of production relative to declining ore grades in the USSR.     

加强生态监测体系建设 服务生态立省战略

根据目前青海省生态监测现状,深入分析了生态监测存在的问题,首次提出了由青海省生态环境监测中心和重点区域生态监测站点为主构建青海省生态监测体系的构想。     

浅谈高速公路的生态绿化

文章针对当前我国高速公路建设中的绿化要求,引入高速公路生态绿化的概念。通过对高速公路建设中生态恢复和景观绿化两大内容的分析,提出了高速公路生态绿化的要点。     

国家北方重要生态安全屏障保护与建设

把内蒙古建成我国北方重要生态安全屏障,是立足全国发展大局确立的战略定位。本文在阐述国家北方重要生态安全屏障概念和内涵的基础上,综述了近年来内蒙古在国家北方重要生态安全屏障保护和建设中取得的进展及效果,对生态服务功能基础进行全面分析总结,剖析了目前和未来生态安全屏障建设中面临的天然生态脆弱、部分生态系统退化、资源环境承载压力大等问题,最后从发展方向、关键技术、政策体系、工程布局和监管能力五个角度提出了内蒙古生态保护与建设的对策建议,为筑牢我国北方重要生态安全屏障提供思路。     

生态补偿后的春天

2012年的春天是个分界点。 自今年1月5日开始,已多年互不交集,还偶尔打些＂嘴仗＂的安徽省黄山市及浙江省杭州市淳安县环保局终于站在了同一战壕里,对两省交界处的新安江江段水质进行联合监测,双方互通有无,交流经验。     

中国长城沿线生态脆弱性分析及生态保护对策

中国长城沿线是半湿润—半干旱和半干旱—干旱气候的过渡地带,也是农牧业的交错地带,生态极其脆弱,生态压力又大,容易发生生态破坏,而且很难恢复。为了保护中国长城沿线的生态环境,必须调整产业结构,合理布局,采用先进技术,加大投入,提高生态意识,加强法制建设。     

文学的生态化走向--关于生态文学的几点思考

生态文学是在全球性环境危机的背景下，伴随着人类生态意识的觉醒和对现代文明的深刻反思而孕育、诞生的一种新型文学形态，同时也是生态学向文学、文学向生态学相互扩张渗透的产物。它以语言艺术构筑的形象抒写人与自然关系的现实，表达人类应有的对待自然的伦理信念、情感态度及行为规范，引领人们进入人与自然和谐共生的审美的理想境界。     

北京市生态涵养区生态服务价值评估与生态补偿机制探讨

在分析北京市生态涵养区在生态补偿制度建设困境的基础上,本文将国内外区域生态系统价值评估模型相结合,运用修正的生态服务价值评估模型,对北京市生态涵养区2016年的生态服务价值进行了估算,并分析了2009-2016年生态服务价值的变动及其影响因素,从科学评估生态服务价值、完善生态补偿标准方法的制定、健全生态保护补偿制度、将绿色GDP纳入生态涵养区绩效考核指标评价体系几个方面探讨了完善生态补偿机制的政策措施。一方面更加直观地揭示了生态涵养区生态服务的重要经济价值,另一方面为建立更加科学的生态补偿机制提供了可参考的依据。