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.     

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.     

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.     

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.     

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。     

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.     

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。     

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。     

论"生态"一词的使用

“生态”一词是目前使用频率较高的词汇之一,但也是很容易使用混淆的词汇之一。“生态”的含义已经由最初生态学中的基本概念和含义扩展了很多,并在许多行业和领域得到广泛应用。其合理应用使生态理念在各个相关领域得到发展,但在使用的过程中,也不乏对其内涵欠缺深入的理解和考究,使其外延过大,使用混乱,出现泛生态化的趋势。本文从生态学的角度分析了“生态”一词的内涵,并对目前广泛流行的一些用法进行讨论,以规范生态概念的使用。     

对生态旅游开发热的思考

针对目前社会上生态旅游开发热的现象,作者通过分析其生产的外在和内在因素,指出这种现象背后潜在的对社会环境的正在效应和负作用,进而提出生态旅游的可开发管理对策。     

积极发展青海生态旅游的思考

生态旅游是当今世界旅游业发展的热点,也是21世纪一个极为重要的旅游经济增长点,青海旅游要实现经济与社会、人与自然的协调发展,就必须把旅游开发与生态建设和环境保护有机结合起来,大力推进生态旅游发展。生态旅游蕴涵着丰富的可持续发展思想,是实现旅游可持续发展的有效途径,发展生态旅游是青海旅游实现可持续发展的必然选择。     

试谈生态工业的建立和发展

党和国家把环境保护作为基本国策,并强调：“正确处理经济发展同人口、资源、环境的关系”。这表明生态问题已经引起高度重视。建立和发展生态工业已成为当前一项重要任务。本文在介绍生态工业定义的基础上,说明了建立和发展生态工业的必要性及如何建立和发展生态工业。     

创新是生态保护工作的动力

针对当前环境保护工作的重心向生态保护转移的原因,对生态保护工作的现状进行了分析,并对生态保护工作的原则进行了阐述。     

蚌埠市的生态建设之路

昨天,我专程到鲍家沟施工现场去看了一下,挖掘机正在清淤呢!4月20日,一名网友将自己的所见发布在蚌埠市当地的     

试论生态补偿的内涵

作者在对国内主流生态补偿观点进行梳理的基础上,认为生态补偿是出于维护适于人类生存和发展的良好生态环境的需要,由生态环境资源的享用人为必要的养护行为或本着公平享用公平负担原则,就其受益承担相应义务,以及相关制度保障的总称。论述了生态补偿的立足点是生态环境,生态补偿的实质是实现人类成员在生态责任和生态利益上的重新分配。     

生态购买是西部生态建设的新战略

生态购买是我国西北地区的强烈要求,也是我国“只能保证过程,不能保证结果”生态建设模式的反思结果。“国有私营”生态购买初衷是政府收购生态建设的产品,既帮助农户脱贫致富,又确保生态建设产品的形成、巩固和转化利用。生态购买以生态建设成果（生态产品）为投资管理的重点,确保生态产品形成效率和转化利用速度,生态效益转化为经济效益。生态购买不仅使生态产品商品化和货币化,实现“生态致富”,更为重要的是培育市场意识、思维、文化,加速培育生态建设市场,充分发挥市场机制的作用,整合社会资源和力量,增强生态建设的实力、能力、吸引力和竞争力。本文经济角度和政策层面．探讨生态购买的产生背景、概念、内涵、原理、功能、方法、程序等。为生态购买的实施提供启发和对策。     

休宁县生态创建结硕果

近年来,安徽省休宁县深入贯彻落实科学发展观,格外重视生态建设和环境保护工作,把加强生态建设、保护和营造优美环境作为一项突出工作来抓,