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11.
Abstract: Success in conservation biology depends upon a synergistic combination of short-term tactics and long-term strategies. Although the former are often necessary to forestall immediate habitat losses, the latter provide the critical framework of understanding needed to develop effective short-term priorities. Although many conservation biologists now emphasize short-term tactics, prudence dictates the concomitant establishment of long-term research projects aimed at answering fundamental ecological questions.
One deterrent to amassing such long-term data bases, aside from time and funding, is a lack of suitable sites where such studies can be conducted on a large scale. We describe two established major land-holding networks in the United States that could serve as appropriate places to develop long-term studies: the National Science Foundation's Long-Term Ecological Research (LTER) sites, and the US. Department of Energy's National Environmental Research Parks (NERPs). Because they consist of established research facilities, both networks can provide conservation biologists with "low-cost" baseline information on ecological processes, as well as access to a number of representative terrestrial and aquatic habitats under more or less "controlled" conditions suitable for long-term studies. We recommend that conservation biologists explore the possibility of using these or similarly available sites in their research programs.  相似文献   
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We sampled understory hummingbirds in Amazonian forest fragments from before isolation through nine years after isolation. We recorded 377 captures of eight species in five 1-ha fragments and four 10-ha fragments. The three species netted before isolation, Phaethornis superciliosus, Phaethornis bourcieri , and Thalurania furcata , were nearly equally abundant at that time. After isolation abundance of P. bourcieri and T. furcata did not change, but P. superciliosus became nearly twice as common. Five additional species that were netted only after isolation represented about 10% of the post-isolation sample. The species recorded only after isolation were forest species usually found above the levels of nets; fragments were not colonized by nonforest species. Use of fragments did not differ between 1- and 10-ha fragments. The landscape surrounding the fragments included active cattle pasture, abandoned pasture, and Cecropia -dominated second growth, but this variation had little effect on use of fragments by hummingbirds. The results suggest that these understory hummingbirds can persist in a matrix of fragments, secondary growth, and large forest patches. This response is much different than that of the insectivorous birds that dominate the understory bird community at the site, which are much more vulnerable to fragmentation.  相似文献   
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Infrastructure and Conservation Policy in Brazil   总被引:1,自引:0,他引:1  
Abstract:  The development of transportation and energy infrastructure has been a major driver in the conversion of natural ecosystems in Brazil since the nineteenth century. Although this pattern is present in most countries, Brazil differs in the scale of opportunities that are still available to build its physical infrastructure while pursuing an ambitious conservation agenda. This advantage stems from the magnitude of intact ecosystems, a dynamic policy environment, and the increasing availability of biological and economic data needed to harmonize conservation with public works. Success depends on integrating conservation and infrastructure planning, rather than relying on the project based, largely ineffective environmental assessment process. Front-loading environmental mitigation and compensation will also help, as will improving public access to, and understanding of, information on the environmental and economic values at stake in major infrastructure decisions.  相似文献   
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Abstract:  Land-reform and environmental movements, revitalized by the democratization of civil society in Brazil in the 1990s, found their objectives in conflict over forested parcels that settlers want for conversion to agriculture but that are important for wildlife conservation. In the Atlantic Forest, where 95% of the forest is gone, we reviewed three cases of Brazilian nongovernmental organization (NGOs) engagement with the land-reform movement with respect to forest remnants neighboring protected areas that have insufficient habitat for the long-term survival of unique endangered species. In the Pontal do Paranapanema (São Paulo), Poço das Antas (Rio de Janeiro), and southern Bahia, environmental NGOs have supported agricultural alternatives that improve livelihood options and provide incentives for habitat conservation planning. Where land-reform groups were better organized, technical cooperation on settlement agriculture permitted the exploration of mutual interests in conciliating the productive landscape with conservation objectives. Processes of regular consultation among NGOs, environmental agencies, and the private sector revealed that there was less zero-sum conflict over the same lands than commonly perceived. In both groups, technicians found forested lands less suitable for small-scale agriculture, and leaders took risks to justify and support claims to alternative existing agricultural lands. Based on the cases we examined, the construction of landscapes with both forest stewardship and poverty-reducing agrarian reform faces continued obstacles from contradictory agrarian and environmental sector policies and inadequate economic incentives for forest stewardship on private lands.  相似文献   
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Abstract:   Resources for prescribed fire are frequently insufficient to manage public lands for all conservation and resource management objectives, necessitating prioritization of the application of fire across the landscape within any given year. Defining tradeoffs when applying prescribed fire to large landscapes is problematic not only because of the complexity of weighing competing management objectives at the landscape scale, but also because of the difficult nature of independently applying need-to-burn criteria to large areas. We present a case study of a simple modeling process implemented at Eglin Air Force Base in the Florida Panhandle (U.S.A.) to prioritize the application of prescribed fire. In a workshop setting, managers and biologists identified key conservation criteria and landscape management objectives that drive the application of prescribed fire. Remote sensing and other spatial data were developed to directly or indirectly represent all these criteria. Using geographic information system software, managers and biologists weighted each criterion according to its relative contribution to overall burn prioritization, and individual values for the criterion were scored according to how they influence the need to burn. Subsequently, this process has been validated and modified through ecological monitoring. This modeling process has also been applied to the 77,400-ha Blackwater River State Forest, public land adjacent to Eglin Air Force Base, demonstrating its applicability to lands with varying management priorities. The advantages of this model-based approach for prioritizing prescribed fire include the reliance on accessible, inexpensive software, the development of spatially explicit management objectives, the ease of transferability, and clearly stated assumptions about management that may be tested and reviewed through monitoring and public comment.  相似文献   
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Although merit pay continues to receive much theoretical and practical attention, little systematic effort is devoted to determining how large a pay raise must be before employees see it as a pay raise. This study uses psychophysical reasoning and techniques in a sample of 192 student ‘employees’ to establish the size of pay raise thresholds in a relatively controlled setting. Results indicate that, below about the 7 per cent level, increases in pay amounts are unlikely to evoke positive perceptual and attitudinal reactions among employees. Theoretical, methodological, and practical implications of these results are highlighted. © 1997 by John Wiley & Sons, Ltd.  相似文献   
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The endangered snail kite (Rostrhamus sociabilis) feeds primarily on the freshwater apple snail (Pomacea paludosa) in Florida. The nonindigenous, floating water hyacinth (Eichhornia crassipes) and water lettuce (Pistia stratiotes) impede kites from finding snails. Effective control of these aquatic plants in the littoral zone of central and south Florida lakes benefits kites by maintaining open foraging habitat. However, incidental herbicide spraying of nesting substrates result in nest collapse when kites breed in nonwoody, emergent plants [cattail (Typha spp.) and giant bulrush (Scirpus validus)] in the outer littoral zone during lower lake levels. Many endangered species recovery plans and their implementation have experienced problems due to inaction and/or noncooperation by various governmental agencies and their personnel. Herein, we describe the development and implementation of a buffer zone strategy to prevent secondary impacts from an aquatic plant control program to snail kites nesting on lakes in central and south Florida. A strategy was jointly developed by personnel of five state and federal agencies to control herbicide application near kite nesting areas during the normal breeding season. Although requiring various modifications during its implementation, this cooperative effort successfully integrated aquatic plant control objectives with snail kite conservation on Lake Okeechobee during 1988. The program was expanded the following year to lakes Kissimmee and Tohopekaliga. Since the implementation of the snail kite impact preclusion program, no nest loss was attributed to incidental herbicide applications on lakes Okeechobee, Kissimmee, and Tohopekaliga.  相似文献   
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Severe winter conditions and blizzards may cause persons to be stranded, unable to move from one place to another. Being stranded under such conditions can be life-threatening and often requires help. This is a study of giving and receiving help among people who were stranded during severe winter conditions and blizzards in Bowling Green, Ohio, USA and the surrounding countryside in 1976–1977. Mail questionnaire data were collected from the Bowling Green, Ohio telephone directory which included listings from both rural and urban areas. The family, followed by friends and neighbors, were most important in the giving and receiving of help. There was little difference between the responses of rural and urban residents. Propinquity was found to be an important intervening variable.  相似文献   
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