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Summary Tropical forests are being destroyed faster than ever, the rate having almost doubled during the 1980s. The main agent of deforestation now turns out to be the displaced peasant or landless farmer, sometimes known as the shifted cultivator; that group accounts for more forest loss than the combined impacts of the commercial logger, the cattle rancher and all other better known sources of deforestation. Yet, the over-riding target of conservation efforts remains the minor players in the forest's decline. All too little attention is directed towards the shifted cultivator, and next to nothing is done to address the problem which this group represents. Policy purviews need to be expanded to include the key factor of the shifted cultivator. In turn, it must determined what impels these people to abandon established farming areas in the countries concerned and to migrate into the forests. It appears that these people are driven by an array of forces: population growth, maldistribution of arable lands, inadequate rural infrastructure and lack of government attention to subsistence agriculture. In other words, the source problem is an amalgam of non-forestry factors, and conservationists will not achieve success in safeguarding the remaining forests unless they direct much more emphasis towards these root causes of deforestation.Dr Norman Myers is a consultant in environment and development, a member of this journal's Advisory Board and a regular contributor to the journal (seeThe Environmentalist,8(3), 187–208 and10(4), 243–256).  相似文献   
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This paper investigates the current treatment of environmental issues by two companies within the large made-to-order sector. Fifty questionnaires were issued to the design team of each company to assess current practice in the integration of environmental issues with design activities, awareness of environmental issues, awareness of existing environmental design tools and the preferred format for a potential clean design tool.  相似文献   
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A large proportion of existing species — possibly half, conceivably even more — may be lost within the foreseeable future. But this may not prove to be the most consequential outcome of the current biodiversity crisis. More significant could be the disruption and degradation of several basic processes of evolution. It appears likely that for mass extinction episodes (MEEs) in the geological past, the recovery period usually lasted at least five million years. Because of certain unique features of the present MEE — notably the near elimination of biomes such as tropical forests, wetlands and coral reefs, which have served as powerhouses of evolution in the past — the bounce-back phase could extend several times longer than five million years. Among distinctive features of future evolution could be; in the short term, homogenization of biotas, a proliferation of opportunistic species, an outburst of speciation among particular taxa, and a pest-and-weed ecology; and, in the long term, a decline of biodisparity, the elimination of megavertebrates, an end to speciation among large vertebrates, and multiple constraints on origination, innovation and adaptive radiation. These disruptive phenomena would rank among the most prominent departures in the entire course of evolution. Full knowledge and understanding of what may characterize future evolution remains largely a black hole of research. As a consequence, conservation policies fail to reflect a further problem of the biodiversity prospect, perhaps exceeding the better recognized problem of the mass extinction of species.Professor Norman Myers is an Editorial Board member and regular contributor toThe Environmentalist. He is an Honorary Visiting Fellow at Green College, Oxford. This paper is a greatly expanded version of a preliminary probing in a popular magazine a decade ago (Myers, 1985). It has been prompted by a major international conference organized by the US National Academy of Sciences, scheduled for late 1996.  相似文献   
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NORMAN MYERS: An honorary visiting fellow at Green College. He is an independent scientist and consultant working in environment and development.Like most other environmental and economic sectors, forestry worldwide looks set to encounter a growing number of surprises in the sense of major divergencies from established trends. These surprises will be largely environmental or economic or both at once. Unless we do a better job of identifying them ahead of time, these surprises will often be of a scale to overwhelm our anticipatory and preventive capacities. Indeed and as this paper demonstrates, the most likely as well as the most taxing forestry problems of the future will often be the ones we have scarcely thought of. Fortunately, the same applies to forestry opportunities. In these circumstances, there is a premium on not only supplying answers to recognized questions but on raising entirely new questions.  相似文献   
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Climate change is altering nutrient cycling within the Arctic Ocean, having knock-on effects to Arctic ecosystems. Primary production in the Arctic is principally nitrogen-limited, particularly in the western Pacific-dominated regions where denitrification exacerbates nitrogen loss. The nutrient status of the eastern Eurasian Arctic remains under debate. In the Barents Sea, primary production has increased by 88% since 1998. To support this rapid increase in productivity, either the standing stock of nutrients has been depleted, or the external nutrient supply has increased. Atlantic water inflow, enhanced mixing, benthic nitrogen cycling, and land–ocean interaction have the potential to alter the nutrient supply through addition, dilution or removal. Here we use new datasets from the Changing Arctic Ocean program alongside historical datasets to assess how nitrate and phosphate concentrations may be changing in response to these processes. We highlight how nutrient dynamics may continue to change, why this is important for regional and international policy-making and suggest relevant research priorities for the future.Supplementary InformationThe online version contains supplementary material available at 10.1007/s13280-021-01673-0.  相似文献   
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Stakeholder analysis means many things to different people. Various methods and approaches have been developed in different fields for different purposes, leading to confusion over the concept and practice of stakeholder analysis. This paper asks how and why stakeholder analysis should be conducted for participatory natural resource management research. This is achieved by reviewing the development of stakeholder analysis in business management, development and natural resource management. The normative and instrumental theoretical basis for stakeholder analysis is discussed, and a stakeholder analysis typology is proposed. This consists of methods for: i) identifying stakeholders; ii) differentiating between and categorising stakeholders; and iii) investigating relationships between stakeholders. The range of methods that can be used to carry out each type of analysis is reviewed. These methods and approaches are then illustrated through a series of case studies funded through the Rural Economy and Land Use (RELU) programme. These case studies show the wide range of participatory and non-participatory methods that can be used, and discuss some of the challenges and limitations of existing methods for stakeholder analysis. The case studies also propose new tools and combinations of methods that can more effectively identify and categorise stakeholders and help understand their inter-relationships.  相似文献   
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This article develops a methodology aimed at generating a systematic social diagnosis of social and natural landscapes. The analytical process is divided into six easily replicable and causatively connected steps. The goal is two-fold: first, to present the inextricable connections between physical landscapes and the communities that occupy them. And second, to provide a fundamental tool to public policy designers that should simultaneously improve social acceptability of conservation policies and policy efficiency and effectiveness. Finally, this methodology is consciously heterogeneous from a theoretical perspective. This article puts together, in fruitful dialogue, contributions from varying places on the social theory spectrum: from political economy to poststructural theory.  相似文献   
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Maternal transfer of brominated flame retardants in zebrafish (Danio rerio)   总被引:1,自引:0,他引:1  
In many species reproduction and embryonic development have been shown to be sensitive to environmental contaminants. Understanding embryonic exposure to environmental contaminants is thus highly important. In this study concentrations of brominated flame retardants (BFRs) were measured in zebrafish eggs after parental exposure for 42 days via the diet. Zebrafish were exposed to two doses of eleven structurally-diverse BFRs. Eight BFRs were detected in the female zebrafish and maternal transfer to eggs was evident for all eight compounds. The highest concentrations in eggs were observed for hexabromocyclododecane (HBCD) and 2,4,4'-tribromodiphenyl ether (BDE 28), followed by 2,2',3,4,4',5',6-heptabromodiphenyl ether (BDE 183) and tetrabromobisphenol A 2,3-dibromopropyl ether (TBBPA DBPE). Five potential BFR metabolites were tentatively identified in female fish and maternal transfer was observed also for these compounds. The lipid adjusted concentrations in eggs were significantly higher than the concentrations in female fish for several of the BFRs. Further, the results showed a generally higher transfer in the lower exposure level and also indicated a dependency on the physico-chemical properties of the compounds.  相似文献   
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