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J. E. Oldfield 《Environmental geochemistry and health》1992,14(3):81-86
Selenium deficiency in soils, and subsequently in crops that are grown on them, has been charted in various parts of the world. Use of carefully regulated amounts of supplemental selenium in such areas has been effective in improving productive performance of domestic food-producing animals, and some 30 years' experience has now been gained with various supplementation practices. Coincidentaliy, there have been instances reported of situations where selenium toxicity has resulted from a combination of naturally-high environmental levels, enhanced by agricultural, environmental and industrial practices, and questions have been raised as to whether continued animal supplementation may contribute to selenium toxicity. This paper examines some of the various factors involved and concludes that presently-established animal supplementation uses of selenium are small compared with other sources of the element and that they do not constitute a hazard to animals, including humans, or the environment. 相似文献
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Habitat Loss and Extinction in the Hotspots of Biodiversity 总被引:34,自引:0,他引:34
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J. A. Dearing R. W. Battarbee R. Dikau I. Larocque F. Oldfield 《Regional Environmental Change》2006,6(1-2):1-16
The analysis of palaeoenvironmental archives—sediments, archaeological remains, tree-rings, documents and instrumental records—is
presented as a key element in the global scientific endeavour aimed at understanding human–environment interactions at the
present day and in the future. The paper explains the need for the focus on palaeoenvironmental studies as a means of ‘learning
from the past’, and presents the rationale and structure of the IGBP-PAGES Focus 5 programme ‘Past Ecosystem Processes and
Human–Environment Interactions’. The past, as described through palaeoenvironmental studies, can yield information about pre-impact
states, trajectories of recent change, causation, complex system behaviour, and provide the basis for developing and testing
simulation models. Learning from the past in each of these epistemological categories is exemplified with published case-studies. 相似文献
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Iain Dickson Stuart H. M. Butchart Allison Catalano David Gibbons Julia P. G. Jones Katie Lee-Brooks Thomasina Oldfield David Noble Stuart Paterson Sugoto Roy Julien Semelin Paul Tinsley-Marshall Rosie Trevelyan Hannah Wauchope Sylvia Wicander William J. Sutherland 《Conservation biology》2023,37(1):e13967
Although some sectors have made significant progress in learning from failure, there is currently limited consensus on how a similar transition could best be achieved in conservation and what is required to facilitate this. One of the key enabling conditions for other sectors is a widely accepted and standardized classification system for identifying and analyzing root causes of failure. We devised a comprehensive taxonomy of root causes of failure affecting conservation projects. To develop this, we solicited examples of real-life conservation efforts that were deemed to have failed in some way, identified their underlying root causes of failure, and used these to develop a generic, 3-tier taxonomy of the ways in which projects fail, at the top of which are 6 overarching cause categories that are further divided into midlevel cause categories and specific root causes. We tested the taxonomy by asking conservation practitioners to use it to classify the causes of failure for conservation efforts they had been involved in. No significant gaps or redundancies were identified during this testing phase. We then analyzed the frequency that particular root causes were encountered by projects within this test sample, which suggested that some root causes were more likely to be encountered than others and that a small number of root causes were more likely to be encountered by projects implementing particular types of conservation action. Our taxonomy could be used to improve identification, analysis, and subsequent learning from failed conservation efforts, address some of the barriers that currently limit the ability of conservation practitioners to learn from failure, and contribute to establishing an effective culture of learning from failure within conservation. 相似文献
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J. A. Dearing R. W. Battarbee R. Dikau I. Larocque F. Oldfield 《Regional Environmental Change》2006,6(1-2):115-123
Leaders of the PAGES Focus 5 programme ‘Past Ecosystem Processes and Human–Environment Interactions’ identify key issues for
research on human–environment interactions for wider discussion. These include the need for long-term perspectives, the opportunities
for maximising palaeoenvironmental research, the need for integration and regionalisation and the challenge of developing
dynamic simulation models. A new organisational matrix for regional studies is outlined, based on a series of zonal/azonal
regions and on the degree of human impact. Future priorities for palaeoenvironmental research include new studies in degraded
human-dominated landscapes, highly-valued ecosystems and sites relevant to other IGBP Core Projects. Simulation of future
human–environment interactions using modelling approaches that have been tested against long records lags behind global climate
modelling, but cellular approaches for biogeophysical and multi-agent systems show promise. 相似文献
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