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Robert M. Lent Marcus C. Waidron John C. Rader 《Journal of the American Water Resources Association》1998,34(2):439-450
ABSTRACT: A multivariate approach was used to analyze hydrologic, geologic, geographic, and water-chemistry data from small order watersheds in the Quabbin Reservoir Basin in central Massachusetts. Eighty three small order watersheds were delineated and landscape attributes defining hydrologic, geologic, and geographic features of the watersheds were compiled from geographic information system data layers. Principal components analysis was used to evaluate 11 chemical constituents collected bi-weekly for 1 year at 15 surface-water stations in order to subdivide the basin into subbasins comprised of watersheds with similar water quality characteristics. Three principal components accounted for about 90 percent of the variance in water chemistry data. The principal components were defined as a biogeochemical variable related to wet. land density, an acid-neutralization variable, and a road-salt variable related to density of primary roads. Three subbasins were identified. Analysis of variance and multiple comparisons of means were used to identify significant differences in stream water chemistry and landscape attributes among subbasins. All stream water constituents were significantly different among subbasins. Multiple regression techniques were used to relate stream water chemistry to landscape attributes. Important differences in landscape attributes were related to wetlands, slope, and soil type. 相似文献
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Abigail Bennett Xavier Basurto John Virdin Xinyan Lin Samantha J. Betances Martin D. Smith Edward H. Allison Barbara A. Best Kelly D. Brownell Lisa M. Campbell Christopher D. Golden Elizabeth Havice Christina C. Hicks Peter J. Jacques Kristin Kleisner Niels Lindquist Rafaella Lobo Grant D. Murray Michelle Nowlin Pawan G. Patil Douglas N. Rader Stephen E. Roady Shakuntala H. Thilsted Sarah Zoubek 《Ambio》2021,50(5):981
The international development community is off-track from meeting targets for alleviating global malnutrition. Meanwhile, there is growing consensus across scientific disciplines that fish plays a crucial role in food and nutrition security. However, this ‘fish as food’ perspective has yet to translate into policy and development funding priorities. We argue that the traditional framing of fish as a natural resource emphasizes economic development and biodiversity conservation objectives, whereas situating fish within a food systems perspective can lead to innovative policies and investments that promote nutrition-sensitive and socially equitable capture fisheries and aquaculture. This paper highlights four pillars of research needs and policy directions toward this end. Ultimately, recognizing and working to enhance the role of fish in alleviating hunger and malnutrition can provide an additional long-term development incentive, beyond revenue generation and biodiversity conservation, for governments, international development organizations, and society more broadly to invest in the sustainability of capture fisheries and aquaculture.Electronic supplementary materialThe online version of this article (10.1007/s13280-020-01451-4) contains supplementary material, which is available to authorized users. 相似文献
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James WS Longhurst 《The Environmentalist》1989,9(4):253-260
Summary This paper reviews the emission sources of oxides of nitrogen and provides an estimate of the contribution from the Greater Manchester conurbation. The uncertainty attached to the estimate is large. Atmospheric and rainwater concentrations of oxides of nitrogen are reported from the Greater Manchester Acid Deposition Survey network. The health and ecological implications of these concentrations are commented upon and the measured values compared to a number of environmental guidelines, including recently formulated critical load and critical level estimates. Control technologies applicable to both mobile and large combustion sources are briefly reviewed.Dr James Longhurst is Director of the Acid Rain Information Centre which is based at Manchester Polytechnic. 相似文献
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Ecological interactions between crops and wild animals frequently result in increases or declines in crop yield. Yet, positive and negative interactions have mostly been treated independently, owing partly to disciplinary silos in ecological and agricultural sciences. We advocate a new integrated research paradigm that explicitly recognizes cost-benefit trade-offs among animal activities and acknowledges that these activities occur within social-ecological contexts. Support for this paradigm is presented in an evidence-based conceptual model structured around five evidence statements highlighting emerging trends applicable to sustainable agriculture. The full range of benefits and costs associated with animal activities in agroecosystems cannot be quantified by focusing on single species groups, crops, or systems. Management of productive agroecosystems should sustain cycles of ecological interactions between crops and wild animals, not isolate these cycles from the system. Advancing this paradigm will therefore require integrated studies that determine net returns of animal activity in agroecosystems.
Electronic supplementary material
The online version of this article (doi:10.1007/s13280-015-0696-y) contains supplementary material, which is available to authorized users. 相似文献5.
Rader WS Solujic L Milosavljevic EB Hendrix JL Nelson JH 《Environmental pollution (Barking, Essex : 1987)》1995,90(3):331-334
Photochemically-induced detoxification of various cyanide species from a selected precious-metal mills tailings was investigated in detail. The studies were conducted in the presence or absence of a titanium (IV) oxide semiconductor photocatalyst utilizing simulated sunlight as the irradiation source. It was established that the cyanide ion (both free and complexed) was photocatalytically oxidized to nitrate via cyanate and nitrite. In addition iron, copper, zinc, mercury and arsenic were stabilized as precipitates. The results obtained may have ramifications for the possible use of solar energy for the efficient treatment of large quantities of precious-metal mill-tailing wastes that contain various cyano-species. 相似文献
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