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171.
The approach developed by Environment Canada to assess risk to aquatic and terrestrial plants in nontarget habitats potentially exposed to pesticides evaluated for registration is described. An anonymous sample of pesticide submissions is used to illustrate the approach and to examine its merits and limitations in relation to test species, response variability, testing protocols, ecological relevance, and comparability with other regulatory agencies. Future directions are identified, particularly in relation to impending nontarget-plant testing guidelines for pesticide registration in Canada. This approach incorporates some of the latest research and developments in the field of risk assessment for plants. The novelty of this approach also lies in the use of the plant screening data routinely generated by chemical pesticide companies, which is intended to provide a maximum amount of information to evaluators at minimal increment cost to registrants. The proposed approach can serve as a basis for guideline development and modernization for other jurisdictions.  相似文献   
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Grazing sea urchins can reduce kelp abundance and therefore strongly affect kelp forest community structure. Despite the ecological importance of sea urchins, direct field studies on the role that urchin predators play in shaping urchin populations are rare for southern California. We conducted surveys and manipulative experiments within kelp forests near San Diego, CA, (32–51′28″N, 117–16′00″W) from 2006 to 2009 to determine whether predators such as sheephead (Semicossyphus pulcher) and spiny lobsters (Panulirus interruptus) may be linked to purple urchin (Strongylocentrotus purpuratus) and red urchin (Strongylocentrotus franciscanus) distribution and habitat use, as well as purple urchin density-dependent mortality. Purple urchins were less dense and more cryptic inside a local marine protected area (MPA) that contained high predator abundance than in nearby heavily fished areas, whereas red urchins rarely were found outside the MPA. Urchin proportional mortality was inversely density dependent during the day when sheephead were active, despite fish aggregations in plots of high urchin density, but was density independent during the night when lobsters were active. Urchin mortality was reduced under understory algal cover during the day, but not during the night. Examining whether urchin mortality from predation is density dependent and how habitat complexity influences this relationship is imperative because behavioral changes and increases in urchin populations can have vast ecological and economic consequences in kelp forest communities.  相似文献   
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This paper addresses the issue of occupational safety and how the process of globalisation can potentially influence the attitudes, beliefs and behaviour of disparate ‘national’ workforces working across the globe for the same multi-national company. The paper reviews published literature on cross-cultural differences in attitudes, perceptions and beliefs regarding safety and presents details of a study examining the relationship between Hofstede’s [Hofstede, G., 1984. Culture’s Consequences; International Differences in Work-Related Values, Abridged edition. Sage Publications, London, Hofstede, G., 1991. Culture and Organisations; Software of the Mind. McGraw Hill, Maidenhead] cultural values dimensions (i.e., Power Distance, Individualism/Collectivism, Masculinity/Femininity); safety climate (perceived management commitment to safety) and risk-taking behaviour in workforce members of a multi-national engineering organisation operating in six countries. The results suggest that more proximal influences such as perceived management commitment to safety and the efficacy of safety measures exert more impact on workforce behaviour and subsequent accident rates than fundamental national values.  相似文献   
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Planners are being called on to prioritize marine shorelines for conservation status and restoration action. This study documents an approach to determining the management strategy most likely to succeed based on current conditions at local and landscape scales. The conceptual framework based in restoration ecology pairs appropriate restoration strategies with sites based on the likelihood of producing long-term resilience given the condition of ecosystem structures and processes at three scales: the shorezone unit (site), the drift cell reach (nearshore marine landscape), and the watershed (terrestrial landscape). The analysis is structured by a conceptual ecosystem model that identifies anthropogenic impacts on targeted ecosystem functions. A scoring system, weighted by geomorphic class, is applied to available spatial data for indicators of stress and function using geographic information systems. This planning tool augments other approaches to prioritizing restoration, including historical conditions and change analysis and ecosystem valuation.  相似文献   
178.
Three studies used digital color photographs to compare responses to natural scenes, skylines after dark, and skylines during the day (seven of each). Study 1 had 59 respondents rate the pleasantness of each scene. They gave similar ratings to Night Skylines and Natural Scenes, and rated each as more pleasant than the Day Skylines. Study 2 had 56 other participants choose from each of seven sets of each kind of scene the one they would most like to have as a framed print in their home or office, and to report the reasons. Participants chose Night Skylines most often, followed by Natural Scenes and then Day Skylines. While participants most often picked attractive as a reason for their choice, those who chose Night Skylines also picked exciting as the reason, and those who picked Natural Scenes also picked relaxing or peaceful as a reason. Study 3 obtained ratings of selected formal features of each scene. The 23 judges rated the Natural scenes as more natural, orderly, open, and curvilinear, less complex, and as having smoother transitions than either Day or Night Skylines; and they judged the Night Skylines as higher in complexity but lower in order than Day Skylines. The results suggest that preferences in relation to the scene categories may well depend on a mix of their formal characteristics and their content.  相似文献   
179.
The aim of this study was to explore the relationship between pro-environmental behaviour and two forms of emotional association: attachment to place and connectedness to nature. This relationship is explored in the context of farmers' management of native vegetation on their properties. A postal survey was conducted to measure the extent to which farmers felt connected to nature and to their property. The survey also measured vegetation management behaviours and associated valued outcomes. A total of 141 farmers in northwest Victoria, Australia, completed the survey. Results showed that vegetation protection behaviours increased with connectedness to nature (CNS), although CNS accounted for only a modest amount of the variation in behaviour. Place attachment was not related to management behaviours. Further analysis suggested that the relationship between CNS and management behaviour was mediated by importance given to environmental benefits of vegetation management. The findings lend weight to studies showing a relationship between CNS and more simple conservation behaviours (e.g. recycling). The findings are also consistent with frameworks suggesting that emotional association with nature leads to an expanded sense of self and greater valuing of non-human species, and so to pro-environment behaviour. This demonstrates the importance of using a range of instrumental and more affective strategies to promote conservation behaviours.  相似文献   
180.
Alkyl nitrates (C1–C5) were measured at two sites (near urban and rural) in southeast England during the Tropospheric Organic Chemistry Experiment (TORCH). Methyl nitrate was the dominant species during both campaigns accounting for on average about one third of the total measured alkyl nitrates. High mixing ratios (>50 pptv) and variability of methyl nitrate were observed at the near urban site (TORCH1) that were not seen at the rural site (TORCH2) and which could not be explained by local photochemical production or direct emissions. The diurnal variation of methyl nitrate during TORCH1 showed a morning maximum that would be consistent with nighttime chemistry followed by transport to the surface by boundary layer dynamics. Similarly, elevated morning mixing ratios were also observed during TORCH2 although the magnitudes were much smaller. As a result, methyl nitrate could represent a tracer for nighttime chemistry seen at the ground the following day. At both campaigns, the dominant source of short chain alkyl nitrates and carbonyl precursor radicals (≤C4) were from decomposition of larger compounds. The magnitude of the source increased with decreasing carbon number consistent with increasing total precursor abundance. Non-photochemical emissions of acetaldehyde and acetone could not be accounted for by automobile exhaust emissions alone and indicated that other direct sources are likely important in this environment.  相似文献   
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