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81.
Using ecological criteria to evaluate wilderness planning options in Idaho   总被引:1,自引:0,他引:1  
Legally designated wilderness areas are acknowledged to be an important element in strategies to conserve biological diversity in United States. However, because of the restrictions on consumptive uses in wilderness, their establishment is normally contentious. Criteria for establishment have typically been associated with opportunity and aesthetic and experiential values. Biological data have not normally played a major role in guiding wilderness establishment. We present four wilderness allocation options for those public lands considered suitable for wilderness designation in Idaho. These options cover the span of choices presently available to wilderness planners in the state and range from not establishing any new wilderness areas to the inclusion of all suitable lands in wilderness. All options are evaluated using spatial biological data from the National Biological Survey's Gap Analysis Project. A conservation strategy that would protect a minimum of 10% of the area occupied by each of 113 native vegetation types and at a minimum 10% of the distribution of each of 368 vertebrate species was evaluated for each option. Only the inclusion of all suitable lands in wilderness, creating a system of 5.1 million ha came close to achieving these goals, protecting 65% of the vegetation types and 56% of the vertebrate species. We feel this approach, which allows planners to evaluate the ecological merits of proposed widerness units along with other values, can provide a means to resolve the impasse over additional wilderness designation in Idaho.  相似文献   
82.
Abstract: A primary water quality problem caused by non-point source pollution (NPSP) is eutrophication, from excess nutrients in receiving water bodies. The control of nutrients arising from NPSP is difficult because the source areas can be hard to identify and typical treatment methods are infeasible due to the distributed nature of the pollutants. It may be possible to reduce nutrient related water quality problems through the restoration of highly disturbed watersheds with best management practices (BMPs). While restoration attempts may provide significant returns, they can be costly to implement and often are met with resistance in agricultural communities. Extending model results beyond the range of calibration to model future conditions such as for restoration scenarios requires the use of physically-based models that include the important processes that generate streamflow and material transport, uptake, loss, transformation, and recycling of nutrients and other material. The research and development objectives of the US. Army Engineer Research and Development Center (ERDC) in Vicksburg, Mississippi, are to develop a watershed assessment and management model to simulate transport, uptake, loss, transformation, and recycling of nutrients such as nitrogen and phosphorus and associated material such as sediment and organic matter. In this study we will discuss current efforts at the ERDC's Environmental Laboratory to develop a state-of-the-art watershed water quality model.  相似文献   
83.
One of the most pressing problems facing wilderness managers in the ecologically fragile Drakensberg Mountains, South Africa, is that of path erosion, since it detracts from the wilderness experience and is very costly to remediate. As increasing demand for wilderness and outdoor recreation places greater pressure on paths and trails, it will be necessary to increase path network size and capacity, and it is important that new paths are routed such that maintenance requirements are minimal. This study describes the development of a technique based on the site and environmental variables of rainfall, topographic slope, and lithology, which enables assessment of path erosion risk before paths are planned and constructed. The technique was tested on a path at the Drakensberg resort of Loteni, and showed good correlation with actual path degradation. When used as a tool in path network planning, it can aid in the selection of low-maintenance routes and also help in planning maintenance budgets.  相似文献   
84.
Integrated Measures of Anthropogenic Stress in the U.S. Great Lakes Basin   总被引:1,自引:0,他引:1  
Integrated, quantitative expressions of anthropogenic stress over large geographic regions can be valuable tools in environmental research and management. Despite the fundamental appeal of a regional approach, development of regional stress measures remains one of the most important current challenges in environmental science. Using publicly available, pre-existing spatial datasets, we developed a geographic information system database of 86 variables related to five classes of anthropogenic stress in the U.S. Great Lakes basin: agriculture, atmospheric deposition, human population, land cover, and point source pollution. The original variables were quantified by a variety of data types over a broad range of spatial and classification resolutions. We summarized the original data for 762 watershed-based units that comprise the U.S. portion of the basin and then used principal components analysis to develop overall stress measures within each stress category. We developed a cumulative stress index by combining the first principal component from each of the five stress categories. Maps of the stress measures illustrate strong spatial patterns across the basin, with the greatest amount of stress occurring on the western shore of Lake Michigan, southwest Lake Erie, and southeastern Lake Ontario. We found strong relationships between the stress measures and characteristics of bird communities, fish communities, and water chemistry measurements from the coastal region. The stress measures are taken to represent the major threats to coastal ecosystems in the U.S. Great Lakes. Such regional-scale efforts are critical for understanding relationships between human disturbance and ecosystem response, and can be used to guide environmental decision-making at both regional and local scales.  相似文献   
85.
86.
Evaluating progress towards environmental sustainability goals can be difficult due to a lack of measurable benchmarks and insufficient or uncertain data. Marine settings are particularly challenging, as stakeholders and objectives tend to be less well defined and ecosystem components have high natural variability and are difficult to observe directly. Fuzzy logic expert systems are useful analytical frameworks to evaluate such systems, and we develop such a model here to formally evaluate progress towards sustainability targets based on diverse sets of indicators. Evaluation criteria include recent (since policy enactment) and historical (from earliest known state) change, type of indicators (state, benefit, pressure, response), time span and spatial scope, and the suitability of an indicator in reflecting progress toward a specific objective. A key aspect of the framework is that all assumptions are transparent and modifiable to fit different social and ecological contexts. We test the method by evaluating progress towards four Aichi Biodiversity Targets in Canadian oceans, including quantitative progress scores, information gaps, and the sensitivity of results to model and data assumptions. For Canadian marine systems, national protection plans and biodiversity awareness show good progress, but species and ecosystem states overall do not show strong improvement. Well-defined goals are vital for successful policy implementation, as ambiguity allows for conflicting potential indicators, which in natural systems increases uncertainty in progress evaluations. Importantly, our framework can be easily adapted to assess progress towards policy goals with different themes, globally or in specific regions.  相似文献   
87.
This study examines the motivations of mainland Chinese facilities in seeking ISO 14001 certification and examines the linkages between these motivations and self-reports of the effectiveness of major environmental management system (EMS) components. In a sample of 128 facilities in Beijing, Shanghai, and Guangzhou, the main drivers for certification were reported to be to ensure regulatory compliance, to enhance the firms reputation, and to improve environmental performance, in that order. Although motivation to achieve cost reductions were least emphasized, a broad range of motivations appears to be considered in the decision to seek certification to ISO 14001. Regression models linking these motivations to the EMS components suggests that internal motivations have an influence on most EMS components. One interesting exception to this, however, is that no significant relationship was observed between internal motivations and the promulgation of environmental objectives and targets. The relationships associated with external motivations for certification (i.e., those in response to customer and other stakeholder pressures) and EMS components, on the other hand, are weaker and tend to occur earlier in the process cycle. No significant relationships were found between motivations to reduce costs and perceptions of the effectiveness of EMS components. Overall, these findings suggest that ISO 14001, as currently being implemented in mainland China, may have a modestly useful role when used in combination with other policy mechanisms to move the Chinese economy toward more sustainable practices. It is asserted that the ISO standard could provide even greater benefits if Chinese registrars were more proactive in developing EMS in conjunction with even more rigorous third-party audits.Published online  相似文献   
88.
PROBLEM: Although personality characteristics such as impulsiveness have been linked to the driving safety and driving habits of young and middle-aged adults, little research has focused on the role of personality in older driver behavior. METHOD: Using the IVE questionnaire in an exploratory study, three personality dimensions (impulsiveness, venturesomeness, and empathy) were measured in 305 older drivers (ages 57-87 years old). In addition, the Driving Habits Questionnaire was used to estimate driving exposure, and the Driver Behavior Questionnaire (DBQ) was used to estimate driving errors and violations. State-recorded crash data were made available by the state public safety agency. RESULTS: Subjects who reported four or more driving errors had higher impulsivity and empathy scores and lower venturesomeness scores. Subjects reporting driving violations were more likely to have high impulsivity scores. Driving six or more places per week was associated with lower levels of impulsivity. IMPACT: These results suggest that a comprehensive understanding of driving problems among older adults should also include a consideration of personality dimensions. In doing so, the challenges faced in the interpretation of self-report instruments on driving behaviors must be acknowledged, with a move in research toward greater reliance on more objective measures of driving behavior when assessing the impact of personality variables.  相似文献   
89.
Due to anthropogenic inputs, elevated concentrations of metals frequently occur in aquatic sediments. In order to make defensible estimates of the potential risk of metals in sediments and/or develop sediment quality criteria for metals, it is essential to identify that fraction of the total metal in the sediments that is bioavailable. Studies with a variety of benthic invertebrates indicate that interstitial (pore) water concentrations of metals correspond very well with the bioavailability of metals in test sediments. Many factors may influence pore water concentrations of metals; however, in anaerobic sediments a key phase controlling partitioning of several cationic metals (cadmium, nickel, lead, zinc, copper) into pore water is acid volatile sulfide (AVS). In this paper, we present an overview of the technical basis for predicting bioavailability of cationic metals to benthic organisms based on pore water metal concentrations and metal-AVS relationships. Included are discussions of the advantages and limitations of metal bioavailability predictions based on these parameters, relative both to site-specific assessments and the development of sediment quality criteria.  相似文献   
90.
The Third World debt crisis has drastically altered the options open to Third World countries to fund petroleum development. Restricted access to international capital markets means that developing countries are having to reconsider alternative financial options to achieve a satisfactory rate of petroleum development. Of these, only foreign direct investmentis capable of compensating for the loss of more traditional sources of funds. To this end, developing countries are revising and harmonizing prior restrictive direct investment rules and tax codes, with recent financial innovations further underwriting the process.  相似文献   
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