The reversible process concept applied to the environmental management of large river systems

The wetland ecosystems occurring within alluvial floodplains change rapidly. Within the ecological successions, the life span of pioneer and transient stages may be measured in several years or decades depending on the respective influences of allogenic (water dynamics, erosion, and deposition) and autogenic developmental processes (population dynamics, eutrophication, and terrestrialization). This article emphasizes the mechanisms that are responsible for the ecosystem changes and their importance to environmental management. Two case studies exemplify reversible and irreversible successional processes in reference to different spatial and temporal scales. On the scale of the former channels, the standing-water ecosystems with low homeostasis may recover their previous status after human action on the allogenic processes. On the scale of a whole reach of the floodplain, erosion and deposition appear as reversible processes that regenerate the ecological successions. The concepts of stability and reversibility are discussed in relation to different spatiotemporal referential frameworks and different levels of integration. The reversible process concept is also considered with reference to the energy inputs into the involved subsystems. To estimate the probability of ecosystem regeneration or the cost of restoration, a concept of degrees of reversibility is proposed.     

A conceptual model for assessing ecological risk to water quality function of bottomland hardwood forests

Ecological risk assessment provides a methodology for evaluating the threats to ecosystem function associated with environmental perturbations or stressors. This report documents the development of a conceptual model for assessing the ecological risk to the water quality function (WQF) of bottomland hardwood riparian ecosystems (BHRE) in the Tifton-Vidalia upland (TVU) ecoregion of Georgia. Previus research has demonstrated that mature BHRE are essential to maintaining water quality in this portion of the coastal plain. The WQF of these ecosystems is considered an assessment endpoit—an ecosystem function or set of functions that society chooses to value as evidenced by laws, regulations, or common usage. Stressors operate on ecosystems at risk through an exposure scenario to produce ecological effects that are linked to loss of the desired function or assessment end point. The WQF of BHRE is at risk because of the ecological and environmental quality effects of a suite of chemical, physical, and biological stressors. The stressors are related to nonpoint source pollution from adjacent land uses, especially agriculture; the conversion of BHRE to other land uses; and the encroachment of domestic animals into BHRE. Potential chemical, physical, and biological stressors to BHRE are identified, and the methodology for evaluating appropriate exposure scenarios is discussed. Field-scale and watershed-scale measurement end points of most use in assessing the effects of stressors on the WQF are identified and discussed. The product of this study is a conceptual model of how risks to the WQF of BHRE are produced and how the risk and associated uncertainties can be quantified.     

灾害生态学问题研究

灾害生态学是从生态进化的角度上研究灾害问题，其目的在于通过对生态灾害的界定，生态灾害成因分析，来寻求防止或减轻生态灾害的有效途径．文章从灾害与生态进化的关系入手，阐述了研究灾害生态学问题的重要意义，提出了当前灾害生态学研究的主要问题，为灾害生态学的研究提供了一条新的思路。     

中国钢铁工业循环经济发展现状及趋势

叙述了我国钢铁工业的产业政策,结构调整,环保与节能降耗,节水与三废治理以及推进清洁生产的基本状况,指出搞好循环经济是钢铁工业发展的必由之路.     

层次分析法在自然保护区生态评价中的应用

对自然保护区的多样性、代表性、稀有性等诸项指标进行分析,以太白山自然保护区为例,运用层次分析法针对自然保护区综合评价之一的生态评价建立层次结构模型,构造各项评价指标的判断矩阵并计算权重,从而得出生态现状评价结果.     

山东省海河流域污染状况及减排对策

水环境恶化已成为山东省海河流域经济社会可持续发展的一大隐忧，整个流域1480km的河长中，已有85％受到污染。从加强排污口规范化整治、设置科学化的监测考核断面、环境监督日常化、建立严格的地方政府考核机制等四个方面，科学地提出了完成减排任务应该采取的对策。     

Modification of ecological footprint evaluation method to include non-renewable resource consumption using thermodynamic approach

This study is to modify the ecological footprint methodology by incorporating non-renewable or abiotic resources as an additional category. The use of abiotic resources can be quantified as global hectare by using thermodynamic approaches. A detailed case study on various countries including Australia, Belgium, Brazil, Canada, Japan, USA, and Vietnam shows the advantage of using the new modified ecological footprint (EF) as an indicator for sustainable development. The modified EF includes not only biotic resources, but also the abiotic resources. The case study indicates that the modified EF differs from the traditional EF up to 123% in the case of Belgium, and 90% in the case of Australia. For developing countries such as Brazil and Vietnam, the differences are relatively smaller (21% for Brazil and 9.4% for Vietnam). The estimated total ecological footprint of the world using the new method implies more serious problems associated with over consumption than using results from the original ecological footprint method.     

当代大学生就业难的道德困境

在当前社会主义市场经济环境下，如何引导好大学毕业生树立正确的就业观，如何平衡功利主义与责任意识、享乐思想与奉献精神之间的关系，如何在企业需求与学校人才培养模式之间形成良性互动，是当前大学教育工作面临的重要课题。充分调动政府、社会、企业、学校各自资源的力量，是解决当代大学生就业困境的重要出路。     

小流域生态经济的实践与探索

我国的小流域治理工作已经开展了几十年，在治理水土流失方面取得了一定的成效。如何巩固已取得的成绩，实现小流域的可持续发展引起了广泛关注。本文通过阐述生态经济的概念，指出小流域生态经济系统存在的问题，并结合小流域的特点探讨了在小流域建设生态经济的途径。     

生态影响评价在旅游景区中的应用--以中山陵园风景区外缘景区为例

采用生态影响评价的工作方法，以中山陵园风景区外缘景区为例，在分析外缘景区生态现状的基础上，从土地利用与水土流失状况、森林群落状况、生物多样性、生态系统等方面对规划产生的生态影响进行了评价，得出外缘规划的实施总体上有利于景区生态可持续发展的结论，最后对评价中有待改进的方面做了几点探讨。