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181.
River basins provide a wide range of ecosystem services important for human well-being. Ecosystem functions and their value to humans have been thoroughly studied. However, the role of governance characteristics for the sustainable management of ecosystem services has been largely ignored up to now. To close this gap, this article introduces the latest modifications to a database building on the Management and Transition Framework (MTF) that serve to study the relationship between water governance and management systems and their performance with regard to impacts on ecosystem services. This comprehensive approach facilitates structured data collection and representation in order to analyze single case studies or compare case studies regarding the governance and management of water resources and associated ecosystem services. It allows the user to investigate whether certain water governance characteristics, such as stakeholder involvement or vertical integration of governance levels, are associated with a change in the management of ecosystem services or a measurable change in their state. A simplified case from South Africa shows how the database modifications allow addressing links between governance and management processes on the one side and ecosystem services and the way they are handled on the other side. Applying the MTF database leads to evidence-based insights into best practices as well as failed management approaches and interventions. This in turn provides knowledge that can be transferred from science to practice supporting sustainable governance of ecosystem services.  相似文献   
182.
本文以碳酸盐体系为基础提出适于区域环境水体酸化敏感性多指标评价模型,利用该模型结合各评价指标的标准化体系可进行大尺度范围水体酸化敏感性评价。  相似文献   
183.
The responses of ecological computer simulations are significantly changed by the inclusion of human behavior patterns. Two computer simulations illustrate this principle for internal and external decision making. The Northwest Educational Trawler Simulation (NETS) models the interaction between fish populations, fishing effort, markets, and a fishing community. This simulation includes an internal decision making submodel for changing fishing effort based on observed behaviors of fishermen. NOGERO, a simulation of a mythical coastal fishing culture, uses external decision making where simulation users act as stewards. The patterns of model response vary depending on the attitudes and goals of decision makers. This shows how human behavior interacts with ecosystem dynamics to produce a variety of results.  相似文献   
184.
This paper suggests a way of classifying human physical environment according to its location and function. Environmental science is viewed as a branch of ecology, and the concept of the complex ecosystem is introduced. By using differential equations, the author draws attention to four factors that must be considered when evaluating the effect of any environmental agent on a human subject: the agent's extensive quality of rate of flow, its intensive quality of concentration or intensity, duration of the subject's exposure, and the uniformity of agent's stress in space and time. The environmental agents, individually or in jointly acting groups, produce environmental stress, which acts on the subject to produce strain and its contingent symptoms. The microclimate in this setting can be classified according to the type of stress involved. The human physical environment may be evaluated in three ways: objectively, subjectively, and from the standpoint of regulations or standards. The benefit or advantage of using this equation in evaluating or measuring the human physical environment is discussed.  相似文献   
185.
In this article, we focus on documented and possible effects of fish stocking in terms of ecosystem services. The increasing use of fish stocking between 1970 and 2000 in the semiurban setting of Stockholm archipelago, Sweden, is used as case study. The objective is to analyze this management practice from an ecosystem perspective, accounting for both the ecological and social context of releasing fish. The results show that enhancements of four native species (Salmo S. trutta, Salmo salar, Stizostedion lucioperca, and Anguilla anguilla) have dominated over new introductions of one nonnative species. (Oncorhynchus mykiss). The major objective has been to increase fish catches for local resource users. Involved stakeholders include three management agencies, one hydropower company, and several local sport fishing associations. Documented effects focus on recapture and production rates. However, our analysis suggests that additional positive or negative effects on biodiversity, food web dynamics, mobile links, or ecological information may also result, with possible consequences for the long-term provision of food, game, and aesthetic values. We conclude that a more adaptive and cooperative management approach could benefit from a deeper analysis of where, when, and what species is released, by whom, which stakeholders that use the fish and those ecosystem services the fish generate, and of the role of formal and informal institutions for monitoring and evaluating the success of releasing fish.  相似文献   
186.
Toxic risk of surface water pollution--six years of experience   总被引:1,自引:0,他引:1  
Assessment of an ecological quality of surface water is necessary for effective protection, abatement and successive revitalisation of river ecosystems. This quality is primarily given by biological impact of surface water pollution. Substances contained in pollution are frequently toxic to aquatic organisms. Risk of chronic impact of surface water pollution is very often underestimated due to hidden long time action of pollutants. Proper estimation of the risk is not possible from results of chemical analyses and data of substances' toxicity. Chemical analyses are not able to detect all substances presented in water including the products of reactions between them. In addition, a simultaneous presence of substances can modify their final effect on aquatic organisms. Therefore, a complex method of assessment of toxic risk of surface water pollution based on ecotoxicological approach was developed. The toxic risk of surface water pollution is determined from results of evaluation of toxic risk of organic part and inorganic part of surface water pollution. Resultant degree of toxic risk of total pollution is given by the highest degree detected in any part of the water pollution. Presented method, which is routinely used for monitoring in the Czech part of the Odra river basin, was fully standardised and published in the form of the Czech branch technical norm of water management (TNV) in the year 2000.  相似文献   
187.
The amount of ecological restoration required to mitigate or compensate for environmental injury or habitat loss is often based on the goal of achieving ecological equivalence. However, few tools are available for estimating the extent of restoration required to achieve habitat services equivalent to those that were lost. This paper describes habitat equivalency analysis (HEA), a habitat-based “service-to-service” approach for determining the amount of restoration needed to compensate for natural resource losses, and examines issues in its application in the case of salt marsh restoration. The scientific literature indicates that although structural attributes such as vegetation may recover within a few years, there is often a significant lag in the development of ecological processes such as nutrient cycling that are necessary for a fully functioning salt marsh. Moreover, natural variation can make recovery trajectories difficult to define and predict for many habitat services. HEA is an excellent tool for scaling restoration actions because it reflects this ecological variability and complexity. At the same time, practitioners must recognize that conclusions about the amount of restoration needed to provide ecological services equivalent to those that are lost will depend critically on the ecological data and assumptions that are used in the HEA calculation.  相似文献   
188.
/ Whereas habitat conservation plans (HCPs) have been intended to provide comprehensive environmental mitigation for multiple species, they often narrow in focus to one species and either one mitigation site or unspecified sites. We developed an indicators framework from which to rate land units for their ecological integrity, collateral values (nonbiological qualities that can improve conservation), and restoration and conservation opportunities. The ratings of land units were guided by the tenets of conservation biology and principles of landscape and ecosystem ecology, and they were made using existing physical and floral information managed on a GIS. As an example of how the indicators approach can be used for HCPs, the 29 legally rare species targeted by the Yolo County HCP were each associated with vegetation complexes and agricultural crops, the maps of which were used for rating some of the landscape indices. The ratings were mapped so that mitigation can be directed to the places on the landscape where the legally rare species should benefit most from conservation practices. The most highly rated land units for conservation opportunity occurred along streams and sloughs, especially where they emerged from the foothills and entered the Central Valley and where the two largest creeks intersected the Sacramento River flood basin. We recommend that priority be given to mitigation or conservation at the most highly rated land units. The indices were easy to measure and can be used with other tools to monitor the mitigation success. The indicators framework can be applied to other large-area planning efforts with some modifications.KEY WORDS: Ecosystem; Indicators; Landscape; Mitigation; Planning; Yolo County; California  相似文献   
189.
夏文汇 《四川环境》1995,14(1):28-31
本文运用生态经济系统思想有计划,有步骤地解决水环境问题,针对当前城市水质污染的状况和趋势,找出城市水污染的主要原因,并对城市水环境污染进行经济分析及采取的经济对策,根据城市污水总量污染趋势预测,提出了防治措施,同时,在解决水环境问题时,重视环境效益,经济效益和社会效益的统一。  相似文献   
190.
Environmental quality assessment has to focus more on the quality of whole ecosystems, instead of focusing on the direct effects of a specific stressor, because of a more integrated environmetal policy approach. Yet, how can the ecosystem quality be measured? Partly this is a normative question, a question of what is considered good and bad. At the same time, it is a scientific question, dealing with the problem of low the state of a system as complex as an ecosystem could be measured. Measuring all abiotic and biotic components, not to mention their many relationships, is not feasible. In this article we review several approaches dealing with this scientific question. Three approaches are distinguished; they differ in type of variable set and ecosystem model used. As a result of this, the information about the state of the ecosystem differs: ultimate breadth, comprising information about the whole ecosystem, is at the expense of detail, while ultimate detail is at the expense of breadth. We discuss whether the resultant quality assessments differ in character and are therefore suitable to answer different policy questions.  相似文献   
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