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1.
Beckman NG  Muller-Landau HC 《Ecology》2011,92(11):2131-2140
The importance of vertebrates, invertebrates, and pathogens for plant communities has long been recognized, but their absolute and relative importance in early recruitment of multiple coexisting tropical plant species has not been quantified. Further, little is known about the relationship of fruit traits to seed mortality due to natural enemies in tropical plants. To investigate the influences of vertebrates, invertebrates, and pathogens on reproduction of seven canopy plant species varying in fruit traits, we quantified reductions in fruit development and seed germination due to vertebrates, invertebrates, and fungal pathogens through experimental removal of these enemies using canopy exclosures, insecticide, and fungicide, respectively. We also measured morphological fruit traits hypothesized to mediate interactions of plants with natural enemies of seeds. Vertebrates, invertebrates, and fungi differentially affected predispersal seed mortality depending on the plant species. Fruit morphology explained some variation among species; species with larger fruit and less physical protection surrounding seeds exhibited greater negative effects of fungi on fruit development and germination and experienced reduced seed survival integrated over fruit development and germination in response to vertebrates. Within species, variation in seed size also contributed to variation in natural enemy effects on seed viability. Further, seedling growth was higher for seeds that developed in vertebrate exclosures for Anacardium excelsum and under the fungicide treatment for Castilla elastica, suggesting that predispersal effects of natural enemies may carry through to the seedling stage. This is the first experimental test of the relative effects of vertebrates, invertebrates, and pathogens on seed survival in the canopy. This study motivates further investigation to determine the generality of our results for plant communities. If there is strong variation in natural enemy attack among species related to differences in fruit morphology, then quantification of fruit traits will aid in predicting the outcomes of interactions between plants and their natural enemies. This is particularly important in tropical forests, where high species diversity makes it logistically impossible to study every plant life history stage of every species.  相似文献   
2.
The results of an empirical study into the perceptions of “hands-on” experts concerning the welfare of (non-human) animals in traveling circuses in the Netherlands are presented. A qualitative approach, based on in-depth conversations with trainers/performers, former trainers/performers, veterinarians, and an owner of an animal shelter, conveyed several patterns in the contextual construction of perceptions and the use of dissonance reduction strategies. Perceptions were analyzed with the help of the Symbolic Convergence Theory and the model of the frame of reference, consisting of knowledge, convictions, values, norms, and interests. The study shows that the debate regarding animals in circuses in the Netherlands is centered on the level of welfare that is required; the importance of animal welfare is not disputed. Arguments that were used differed according to the respondents’ specific backgrounds and can be placed on a gradient ranging from the conviction that the welfare of animals in circuses is sufficiently warranted and both human and animal enjoy the performance (right end), to the conviction that animal welfare in circuses is negative, combined with the idea that the goal of entertaining people does not outweigh that (left end). The study confirms that perceptions reflect people’s contexts, though the variety in scopes suggests that the (inter)relations between people and their context are complex in nature. Evidence of cognitive dissonance was abundant. Coping strategies were found to be used more by respondents towards the right end of the gradient, suggesting that those respondents experience more ambivalence. This encountered pattern of association between position on the gradient and frequency of dissonance reduction strategies calls for further research on the type of ambivalent feelings experienced. The authors argue that, to come to an agreement about the welfare of animals in circuses, including the way this welfare should be guaranteed, stakeholders from different contexts need to engage in a dialogue in which a distance is taken from right/wrong-schemes and that starts from acceptance of dilemmas and ambiguity.  相似文献   
3.
Journal of Polymers and the Environment - Exposure to potentially toxic metallic elements (PTME) released in watercourses by industries results in irreversible damage to living beings or even...  相似文献   
4.
Journal of Polymers and the Environment - Macadamia is a nut widely used globally in food, personal hygiene products, and human health. After removing the nut, high amounts of the shell residual,...  相似文献   
5.
Adaptive management implies a continuous knowledge‐based decision‐making process in conservation. Yet, the coupling of scientific monitoring and management frameworks remains rare in practice because formal and informal communication pathways are lacking. We examined 4 cases in Micronesia where conservation practitioners are using new knowledge in the form of monitoring data to advance marine conservation. These cases were drawn from projects in Micronesia Challenge jurisdictions that received funding for coupled monitoring‐to‐management frameworks and encompassed all segments of adaptive management. Monitoring in Helen Reef, Republic of Palau, was catalyzed by coral bleaching and revealed evidence of overfishing that led to increased enforcement and outreach. In Nimpal Channel, Yap, Federated States of Micronesia (FSM), monitoring the recovery of marine food resources after customary restrictions were put in place led to new, more effective enforcement approaches. Monitoring in Laolao Bay, Saipan, Commonwealth of the Northern Mariana Islands, was catalyzed by observable sediment loads from poor land‐use practices and resulted in actions that reduced land‐based threats, particularly littering and illegal burning, and revealed additional threats from overfishing. Pohnpei (FSM) began monitoring after observed declines in grouper spawning aggregations. This data led to adjusting marine conservation area boundaries and implementing market‐based size class restrictions. Two themes emerged from these cases. First, in each case monitoring was conducted in a manner relevant to the social and ecological systems and integrated into the decision‐making process. Second, conservation practitioners and scientists in these cases integrated culturally appropriate stakeholder engagement throughout all phases of the adaptive management cycle. More broadly, our study suggests, when describing adaptive management, providing more details on how monitoring and management activities are linked at similar spatial scales and across similar time frames can enhance the application of knowledge.  相似文献   
6.
We compare a global model of mercury to sediment core records to constrain mercury emissions from the 19th century North American gold and silver mining. We use information on gold and silver production, the ratio of mercury lost to precious metal produced, and the fraction of mercury lost to the atmosphere to calculate an a priory mining inventory for the 1870s, when the historical gold rush was at its highest. The resulting global mining emissions are 1630 Mg yr?1, consistent with previously published studies. Using this a priori estimate, we find that our 1880 simulation over-predicts the mercury deposition enhancements archived in lake sediment records. Reducing the mining emissions to 820 Mg yr?1 improves agreement with observations, and leads to a 30% enhancement in global deposition in 1880 compared to the pre-industrial period. For North America, where 83% of the mining emissions are located, deposition increases by 60%. While our lower emissions of atmospheric mercury leads to a smaller impact of the North American gold rush on global mercury deposition than previously estimated, it also implies that a larger fraction of the mercury used in extracting precious metals could have been directly lost to local soils and watersheds.  相似文献   
7.
Journal of Material Cycles and Waste Management - The search for environmental sustainability has stimulated the construction sector to look for natural materials with an ecological footprint, high...  相似文献   
8.
Despite decades of scientific research and policy actions to control mercury, exposure to toxic methylmercury continues to pose risks to humans and the environment. This article critically reviews the linkages between scientific advancements and mercury reduction policies aimed at reducing this risk, focusing on the challenges that mercury poses as an issue that crosses both spatial and temporal scales. Scientific aspects of the mercury issue at various spatial and temporal scales are reviewed, and policy examples at global, national and local scale are analysed. Policy activity to date has focused on the mercury problem at a single level of spatial scale, and on near-term timescales. Efforts at the local scale have focused on monitoring levels in fish and addressing local contamination issues; national-scale assessments have addressed emissions from particular sources; and global-scale reports have integrated long-range transport of emissions and commercial trade concerns. However, aspects of the mercury issue that cross the political scale (such as interactions between different forms of mercury) as well as contamination problems with long timescales are at present beyond the reach of current policies. It is argued that these unaddressed aspects of the mercury problem may be more effectively addressed by (1) expanded cross-scale policy coordination on mitigation actions and (2) better incorporating adaptation into policy decision-making to minimize impacts.  相似文献   
9.
Despite framing being a powerful mechanism in policy agenda setting, the planning and policy science literature does not yet devote much attention to the analysis of interactional framing processes in policy change processes. We analyse the framing processes that preceded tipping points in the mobilization of policy attention in a Dutch peri-urban region that over time managed to position the development of landscape values on the agendas of local and regional governments, despite various institutional barriers and blockages. After identifying tipping points in the agenda-setting process, and shifts in frames and coalitions, the paper discusses why these shifts occurred. Two framing mechanisms are identified: (1) framing issues, relationships, and interaction processes in conjunction with one another and (2) resemiotizing original frames to establish a fit to the self-referential frames of targeted supporters within and outside government. The conclusion is that a research focus on human interactions at the grassroots level and on the processes of meaning construction over time reveals detailed insights about why and how structural change and transitions come about. The paper concludes with some lessons for policy-makers and planners with regard to developing a more adaptive attitude to emerging initiatives in civil society.  相似文献   
10.
Changes in atmospheric mercury deposition are used to evaluate the effectiveness of regulations controlling emissions. This analysis can be complicated by seemingly incongruent data from different model runs, model types, and field measurements. Here we present a case study example that describes how to identify trends in regional scale mercury deposition using best-available information from multiple data sources. To do this, we use data from three atmospheric chemistry models (CMAQ, GEOS-Chem, HYSPLIT) and multiple sediment archives (ombrotrophic bog, headwater lake, coastal salt marsh) from the Bay of Fundy region in Canada. Combined sediment and modeling data indicate that deposition attributable to US and Canadian emissions has declined in recent years, thereby increasing the relative significance of global sources. We estimate that anthropogenic emissions in the US and Canada account for 28-33% of contemporary atmospheric deposition in this region, with the rest from natural (14-32%) and global sources (41-53%).  相似文献   
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