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1.
Bioassessment is used worldwide to monitor aquatic health but is infrequently used with risk-assessment objectives, such as supporting the development of defensible, numerical water-quality criteria. To this end, we present a generalized approach for detecting potential ecological thresholds using assemblage-level attributes and a multimetric index (Index of Biological Integrity—IBI) as endpoints in response to numerical changes in water quality. To illustrate the approach, we used existing macroinvertebrate and surface-water total phosphorus (TP) datasets from an observed P gradient and a P-dosing experiment in wetlands of the south Florida coastal plain nutrient ecoregion. Ten assemblage attributes were identified as potential metrics using the observational data, and five were validated in the experiment. These five core metrics were subjected individually and as an aggregated Nutrient–IBI to nonparametric changepoint analysis (nCPA) to estimate cumulative probabilities of a threshold response to TP. Threshold responses were evident for all metrics and the IBI, and were repeatable through time. Results from the observed gradient indicated that a threshold was 50% probable between 12.6 and 19.4 g/L TP for individual metrics and 14.8 g/L TP for the IBI. Results from the P-dosing experiment revealed 50% probability of a response between 11.2 and 13.0 g/L TP for the metrics and 12.3 g/L TP for the IBI. Uncertainty analysis indicated a low (typically 5%) probability that an IBI threshold occurred at 10 g/L TP, while there was 95% certainty that the threshold was 17 g/L TP. The weight-of-evidence produced from these analyses implies that a TP concentration > 12–15 g/L is likely to cause degradation of macroinvertebrate assemblage structure and function, a reflection of biological integrity, in the study area. This finding may assist in the development of a numerical water-quality criterion for TP in this ecoregion, and illustrates the utility of bioassessment to environmental decision-making.  相似文献   

2.
Scholarly critics such as Wendell Berry, as well as the popular media, frequently refer to problems associated with agriculture as the agricultural crisis or the farm crisis. Despite the identification of a problem or problems as symptomatic of this crisis, scant attention is paid to why the situation is a social crisis as opposed to a problem, tragedy, trend, or simple change in the structure of agriculture. This paper analyzes the use of social crisis as applied to the state of modern agriculture and, by extension, other crises such as those in legitimation and morality. It concludes that, although important social values associated with farming as a way of life may be in danger of being lost, the crisis we may be facing with respect to agriculture is more properly understood as a sociopolitical crisis that has broader implications than simply the loss of farms or traditional farming values. Indeed, what is in danger of being lost is our ability to affect a secure and sustainable political-economic system.  相似文献   

3.
Arsenic levels in seawater, microplankton (diatoms and dinoflagellates), shrimp (Penaeus semisulcatus), mollusc (Cerithium scabridum) and five types of fish (Maid, Nakroor, Nuwaiby, Suboor and Sheim) in five sampling stations (I–V) off the Kuwait coast were determined during the years 1995 to 1999. The maximum mean concentration of arsenic was observed in the order; the five fish (0.50–0.78 g g–1)> mollusc (0.26 g g–1)> shrimp (0.23 g g–1)> particulate matter (0.03 g g–1)> water and phytoplankton (0.02 g g–1) from all the sites of the Kuwait coast. Station II possessed the maximum arsenic levels. In comparison with the arsenic levels in other parts of the globe, low arsenic levels were observed in most of the marine organisms off the Kuwait Coast. However, an increasing trend in arsenic concentrations was anticipated due to rapid local industrialization and on account of recent spills of arsenic compounds.  相似文献   

4.
This article describes and illustrates an accounting method to assess and compare early carbon sequestration investments and trades on the basis of the number of standardized CO2 emission offset credits they will provide. The gold standard for such credits is assumed to be a relatively riskless credit based on a CO2 emission reduction that provides offsets against CO2 emissions on a one-for-one basis. The number of credits associated with carbon sequestration needs to account for time, risk, durability, permanence, additionality, and other factors that future trade regulators will most certainly use to assign official credits to sequestration projects. The method that is presented here uses established principles of natural resource accounting and conventional rules of asset valuation to score projects. A review of 20 early voluntary United States based CO2 offset trades that involve carbon sequestration reveals that the assumptions that buyers, sellers, brokers, and traders are using to characterize the economic potential of their investments and trades vary enormously. The article develops a universal carbon sequestration credit scoring equation and uses two of these trades to illustrate the sensitivity of trade outcomes to various assumptions about how future trade auditors are likely to score carbon sequestration projects in terms of their equivalency with CO2 emission reductions. The article emphasizes the importance of using a standard credit scoring method that accounts for time and risk to assess and compare even unofficial prototype carbon sequestration trades. The scoring method illustrated in this article is a tool that can protect the integrity of carbon sequestration credit trading and can assist buyers and sellers in evaluating the real economic potential of prospective trades. Published online  相似文献   

5.
Summary Biosphere reserves are protected areas of representative environments internationally recognised for their value for conservation and for their ability to provide the scientific knowledge, skills and human values to support sustainable development. Biosphere reserves — as a part of the UNESCO programme Man and the Biosphere (MAB) — make up a world-wide network sharing research information on ecosystem conservation, management and development. They include strictly protected core-areas — representative examples of natural or minimally disturbed ecosystems. Core areas are surrounded by buffer zones in which research, environmental education and training and recreation can take place. Buffer zones are, in turn, surrounded by transition areas, large open areas where the aim is to ensure rational development of the natural resources of the region. At present, twelve biosphere reserves are designated in Germany, covering in all an area of 11,589 km2. The role of biosphere reserves to support sustainable development in Germany and Europe is discussed.Karl-Heinz Erdmann is a geographer and Deputy Secretary General at the Secretariat of the German National Committee for the UNESCO Programme on Man and Biosphere (MAB), Federal Agency for Nature Conservation. He is also a Committee Member of the Society for Man and Environment (GMU).  相似文献   

6.
Summary Technological optimism is the doctrine that a growing number of technological improvements in such areas as food production, environmental quality and energy will sustain life as human population soars. It evolved as a response to the Malthusian study The Limits to Growth (The Club of Rome, 1972). Like population biologist Paul Ehrlich, Professor James Krier of the University of Michigan Law School believes that the technological optimists may be wrong. Krier describes how the marginal costs of pollution control increasingly rise. He faults biologist Barry Commoner for neglecting population growth as the cause of pollution and positing the postwar technological transition as its cause. He argues that population growth forced this transition as science searched for substitutes for dwindling resources. Krier criticises as an article of faith the technological optimists' belief that S-curve patterns of technological advance will always arrive in response to the J-curve of exponential population growth. He thinks that the technological optimists may be deluding humanity by predicting the continual emergence of technological breakthroughs at ever-increasing rates. He favours growth policies that would allow humanity to ease into a steady state of resource use and minimise the maximum cost, which would be a global crash after technological innovation fails. Krier laments that modern technolgy can worsen pollution and invites problems of latency, irreversibility, zero-infinity risk and remoteness. He thinks that approapriate technologies which have failed economically may fail politically because the political process has been captured by opposing interests. Krier urges that the population crisis should be adressed insteadAndrew D. Basiago is a graduate of UCLA and Northwestern School of Law's environmental law programme. As writer, lawyer and environmental planner he has written articles about ecology for the Cousteau Society and interviewed such luminaries as R. Buckminster Fuller, Amory B. Lovins and  相似文献   

7.
Summary The author considers various moral, social and political issues that have become apparent from the aftermath of the WWF's twenty-fifth Anniversary Celebrations in Assisi, Italy. In particular, the difficulty of making people understand the very ethics of conservation, when their cultural history has shaped their minds quite differently, is highlighted, and this is reflected in the author's suggested subtitle for the paper, How to Love Nature Without Getting your Shoes Wet.But don't ever leave me alone with Nature, For I know too much about her not to be afraid (Alfred de Vigny)Maria Luisa Cohen is President of the Assisi Nature Council (See also,The Environmentalist, 5 (3) 227–229).  相似文献   

8.
It is the contention of this paper that some progress in alleviating the social and environmental problems which are beginning to face Papua New Guinea can be achieved by supporting traditional Melanesian values through maintaining the customary system of communal land tenure. In accordance with this aim, I will proceed to contrast certain Western attitudes towards individual freedom, selfinterested behaviour, individual and communal interests and private ownership with attitudes and values expressed in the traditional Melanesian approach. In order to demonstrate the latter, I will briefly touch upon the phenomenon of wantokism and indicate how the Melanesian values associated with this concept find their locus in the system of customary communal ownership. Subsequently, I will describe how the emergence of a cash economy and the attachment to Western gadgetry and products have effected injury to the environment and undermined values which have previously maintained Melanesian social cohesion. While admitting that little can be done to eradicate the desire for cash and the products it can buy, I suggest that Melanesian communities and the environment itself would receive more protection if future development in Papua New Guinea embraced a system which incorporated certain of the traditional Melanesian values through the preservation of the communal form of land tenure. Ultimately, I suggest a way in which customary communal land tenure can be integrated into the established Anglo-Australian legal system.  相似文献   

9.
Colorado, USA, developed the Joint Review Process (CJRP) in 1978 to coordinate the application and review of permits required for major development projects. Since then, the state has used the process on over 20 projects. This study examined whether the CJRP has achieved its primary goals—enhanced coordination of agencies, enhanced public participation, and strengthened communication between agencies and project sponsors— and several related secondary goals. The success of the process was measured through a survey of 54 key people who had been directly involved with the process. Those surveyed included federal and state agency staff, local agency managers, corporate officers, private consultants, and environmental leaders. All groups, with one exception, agreed that the process achieved its primary goals and that it should be retained. Environmental leaders were neutral about whether the process enhanced public participation and about retaining the process. The report concludes with a review of recommended improvements to and applications of the CJRP.  相似文献   

10.
Summary Effective communication concerning environmental issues can take a variety of forms. The following essay is offered as a metalogue, a piece of writing in which the writing itself illustrates the principles developed in the writing.International readers will be helped if they know that Jack Armstrong and Sergeant Preston are heroes of moralizing (and often jingoistic) radio dramas popular among children in the United States during the War years and that the Tom Mix Holster Set and the A-bomb Ring were premiums offered to children in boxes of cold cereal in the period after the War. These trivia illustrate the kinds of societal messages directed toward the generation of Americans who presumably will be running the country during the 1980s.The authors are a professor of Psychology and Ethology and a graduate student in International Development. Both attended Harvard University in the late 1950s and the University of California, Berkeley, in the early 1960s. Their autobiographical reflections have something to say about the motivation underlying the environmental movement and where these motivations are likely to lead in the near future.  相似文献   

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