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31.
Chris Riedy Jennifer Kent Nivek Thompson 《Journal of Environmental Planning and Management》2019,62(1):151-171
Effective environmental governance requires institutional change. While some actors work to change institutions, others resist change by defending and maintaining institutions. Much of this institutional work is ‘meaning work’, which we define as the practice of crafting, adapting, connecting and performing meanings to purposively create, maintain or disrupt institutions. This paper constructs a concept of meaning work that highlights agency in carrying meanings across scales and between discursive layers, while noting the structuring role of prevailing discourses. It grounds the concept using two environmental governance cases at very different scales: a local democratic innovation employed by Noosa Council in Queensland, Australia; and the international campaign to divest from fossil fuels. The cases demonstrate the diversity of meaning work and the difficulty of achieving deep discursive change. They point to the need for environmental governance practitioners to rework existing meanings to construct compelling stories for change, taking advantage of narrative openings. 相似文献
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Francis K Wiese Julia K Parrish Christopher W Thompson Christina Maranto 《Ecological applications》2008,18(3):681-700
Predator-prey relationships are often altered as a result of human activities. Where prey are legally protected, conservation action may include lethal predator control. In the Columbia River basin (Pacific Northwest, USA and Canada), piscivorous predators have been implicated in contributing to a lack of recovery of several endangered anadromous salmonids (Oncorhynchus spp.), and lethal and nonlethal control programs have been instituted against both piscine and avian species. To determine the consequences of avian predation, we used a bioenergetics approach to estimate the consumption of salmonid smolts by waterbirds (Common Merganser, California and Ring-billed Gull, Caspian Tern, Double-crested Cormorant) found in the mid-Columbia River from April through August, 2002-2004. We used our model to explore several predator-prey scenarios, including the impact of historical bird abundance, and the effect of preserving vs. removing birds, on smolt abundance. Each year, <1% of the estimated available salmonid smolts (interannual range: 44,830-109,209; 95% CI = 38,000-137,000) were consumed, 85-98% away from dams. Current diet data combined with historical gull abundance at dams suggests that past smolt consumption may have been 1.5-3 times current numbers, depending on the assumed distribution of gulls along the reaches. After the majority (80%) of salmonid smolts have left the study area, birds switch their diet to predominantly juvenile northern pikeminnow (Ptychocheilus oregonensis), which as adults are significant native salmonid predators in the Columbia River. Our models suggest that one consequence of removing birds from the system may be increased pikeminnow abundance, which--even assuming 80% compensatory mortality in juvenile pikeminnow survival--would theoretically result in an annual average savings of just over 180,000 smolts, calculated over a decade. Practically, this suggests that smolt survival could be maximized by deterring birds from the river when smolts are present, allowing bird presence after the diet switch to act as a tool for salmonid-predator control, and conducting adult-pikeminnow control throughout. Our analysis demonstrates that identifying the strength of ecosystem interactions represents a top priority when attempting to manage the abundance of a particular ecosystem constituent, and that the consequences of a single-species view may be counterintuitive, and potentially counterproductive. 相似文献
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Douglas A. Wolfe K. John Scott John R. Clayton Jr. John Lunz James R. Payne Timothy A. Thompson 《Chemistry and Ecology》2013,29(1-2):137-156
Abstract Standardized tests were applied to aromatic and polar fractions of sediment extracts to determine whether polar constituents or oxidative degradation products contributed significantly to the toxicity of sediments oiled by the Exxon Valdez spill. Intertidal sediment and pore-water samples were collected in September 1990 from two heavily oiled sites and an unoiled site in Prince William Sound (PWS). Methylene chloride extracts from these samples were fractionated by liquid chromatography into aliphatic, aromatic and polar fractions, and the aromatic and polar fractions were tested for toxicity using the MicrotoxR test, bivalve larval mortality and development (Mytilus); several measures of genotoxicity in Mytilus, including SOS ChromotestR, anaphase aberrations and sister chromatid exchange; and survival, anaphase aberrations and teratogenicity in coho salmon (Onchorhynchus kisutch). MicrotoxR and SOS ChromotestR protocols were applied in a screening mode to all samples, whereas other tests were applied only to selected fractions from two sites. Samples from Bay of Isles (oiled) were consistently more toxic (usually only 2 to 5-fold) than the Mooselips Bay (unoiled) samples, which gave very low responses in all tests. for both sites, however, responses to polar and aromatic fractions were about the same in most tests, suggesting that while the overall toxicity of the oil was low in these samples, at least part of that toxicity was derived from polar constituents. Compared to the parent hydrocarbons, polar oxidation products partition preferentially into pore-water and are more rapidly diluted and dispersed in the water column. These results suggest that polar oxidation products of petroleum hydrocarbons pose little risk to marine organisms, except possibly for infauna continuously exposed to pore-water in heavily oiled sediments. Independent surveys showed that sediment toxicity in PWS declined during 1989–1991 to near background levels, in accord with previous understanding of oil weathering and toxicity. 相似文献
36.
S. Thompson J. R. Treweek D. J. Thurling 《Journal of Environmental Planning and Management》1997,40(2):157-172
Environmental assessment (EA) of the impacts of development is required under the 1985 European Directive 85/337/EEC, which is implemented in Britain primarily through the 1988 Town and Country Planning (Assessmentof Environmental Effects) Regulations. Ecology provides analytical procedures for studying relationships between organisms and their environment and therefore has an obvious role in EA. The status of ecology within the British EA process was investigated by analysing 179 environmental statements (ESs) produced between 1988 and 1993. In many cases, the ecological information provided was so limited in quantity, or of such poor quality, that it was not possible to assess the ecological implications of proposed schemes. Many ESs failed to provide the data necessary to predict ecological impacts. Potential ecological impacts were reported in 93% of statements, but only 9% made any attempt to quantify them. Of those ESs which made references to ecological effects, only 45% based their findings on new ecological survey information. Consultation with statutory consultees for nature conservation was reported in 48% of ESs. Although 78% of ESs mentioned mitigation measures, only 23% described them in detail. A major shortcoming was the universal failure to make any commitment to monitoring of development impacts. In addition to the lack of formal requirements for monitoring, the lack of guidance for ecologists and developers involved in EA is concluded to be a major factor behind some of the shortcomings summarized in this paper. 相似文献
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Ken Rainwater Andrew Jackson Wesley Ingram Chang Yong Lee David Thompson Tony Mollhagen Heyward Ramsey Lloyd Urban 《Water environment research》2005,77(2):150-161
Drainfields for disposal of septic tank effluents are typically designed by considering the loss of water by either upward evapotranspiration into the atmosphere or lateral and downward absorption into the adjacent soil. While this approach is appropriate for evapotranspiration systems, absorption systems allow water loss by both mechanisms. It was proposed that, in areas where high evapotranspiration rates coincide with permeable soils, drainfield sizes could be substantially reduced by accounting for both mechanisms. A two-year field demonstration was conducted to determine appropriate design criteria for areas typical of the Texas High Plains. The study consisted of evaluating the long-term acceptance rates for three different drainfield configurations: evapotranspiration only, absorption only, and combined conditions. A second field demonstration repeated the experiments for additional observation of the combined evapotranspiration and absorption and achieved similar results as the first study. The field tests indicated that the current design loading criteria may be increased by at least a factor of two for the Texas High Plains region and other Texas areas with similar soil composition and evapotranspiration rates, while still retaining a factor of safety of two. 相似文献
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Numerous cases of hereditary diseases and disorders have been reported in wild animals bred in captivity, but little attention has been paid to the particular genetic management problems that arise when such defects occur. These problems include the obstacle of eliminating the deleterious allele(s) without contemporary loss of genetic variability. In this paper we use the statistical methods of pedigree analysis to address questions regarding a previously presumed hereditary form of blindness observed in a captive wolf population bred for conservation purposes in Scandinavian zoos. The most likely mode of inheritance coincides with an autosomal recessive allele with either a full penetrance or a reduced penetrance of 0.6 (depending on the reliability of studbook records). Using these two models of inheritance, we calculate the probability of carrying the blindness allele for each living animal. Analysis of the effect of removing high-probability carriers on founder allele survival and level of inbreeding demonstrates that the frequency of the deleterious allele can be significantly reduced without seriously affecting founder allele survival or current degree of inbreeding in the wolf population. 相似文献