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11.
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   
14.
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   
15.
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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The effect of humic acid (HA) on Cu uptake by a bacterium and two bacterivorus ciliates was investigated. The presence of HA resulted in a statistically significant (p<0.001) decrease in Cu associated with bacteria that were exposed to 67 microg Cu L(-1). Complexation of Cu appears to lower the availability of Cu with respect to bacterial cell surface binding and uptake. For ciliates, 10 mg HA L(-1) significantly reduced uptake of Cu by Uronema, but did not reduce uptake of Cu by Pleuronema. Uronema exposed to 67 microg Cu L(-1) accumulated 54% less Cu when 10 mg HA L(-1) was present (0.50 pg ciliate(-1) vs 0.23 pg ciliate(-1)). Uronema feeding on V. natriegens, took up less than half as much Cu as unfed Uronema when exposed to Cu without HA (0.41 pg Cu fed ciliate(-1) vs 0.86 pg Cu unfed ciliate(-1), but only 40% less when exposed to Cu and HA (0.31 pg Cu fed ciliate(-1) vs 0.51 pg Cu unfed ciliate(-1)). The lower % reduction attributable to fed ciliates in the presence of HA suggests that some of the Cu associated with HA is available through trophic processes.  相似文献   
18.
The U.S. Endangered Species Act grants protection to species, subspecies, and "distinct population segments" of vertebrate species. Historically, Congress included distinct population segments into endangered species legislation to enable the U.S. Fish and Wildlife Service to implement a flexible and pragmatic approach in listing populations of vertebrate species. Recently, the U.S. Fish and Wildlife Service and the National Marine Fisheries Service have proposed a policy that would narrowly define distinct population segments as evolutionarily significant units based on morphological and genetic distinctiveness between populations. Historically, the power to list species or populations as distinct population segments has been used to tailor management practices to unique circumstances; grant varied levels of protection in different parts of a species' range; protect species from extinction in significant portions of their ranges as well as to protect populations that are unique evolutionary entities. A strict redefinition of distinct population segments as evolutionarily significant units will compromise management efforts because the role of demographic and behavioral data will be reduced. Furthermore, strictly cultural, economic, or geographic justifications for listing populations as threatened or endangered will be greatly curtailed.  相似文献   
19.
Abstract: Abandonment of agricultural land has resulted in forest regeneration in species‐rich dry grasslands across European mountain regions and threatens conservation efforts in this vegetation type. To support national conservation strategies, we used a site‐selection algorithm (MARXAN) to find optimum sets of floristic regions (reporting units) that contain grasslands of high conservation priority. We sought optimum sets that would accommodate 136 important dry‐grassland species and that would minimize forest regeneration and costs of management needed to forestall predicted forest regeneration. We did not consider other conservation elements of dry grasslands, such as animal species richness, cultural heritage, and changes due to climate change. Optimal sets that included 95–100% of the dry grassland species encompassed an average of 56–59 floristic regions (standard deviation, SD 5). This is about 15% of approximately 400 floristic regions that contain dry‐grassland sites and translates to 4800–5300 ha of dry grassland out of a total of approximately 23,000 ha for the entire study area. Projected costs to manage the grasslands in these optimum sets ranged from CHF (Swiss francs) 5.2 to 6.0 million/year. This is only 15–20% of the current total estimated cost of approximately CHF30–45 million/year required if all dry grasslands were to be protected. The grasslands of the optimal sets may be viewed as core sites in a national conservation strategy.  相似文献   
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