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151.
Dimock  R. V.  Groves  K. H. 《Marine Biology》1975,33(4):301-308
Marine Biology - The combined effects of temperature and salinity on the rate of oxygen consuption by the estuarine crab Panopeus herbstii Milne-Edwards (Crustacea: Decapoda: Xanthidae) were...  相似文献   
152.
There is a growing recognition that knowledge of indigenous communities, based on accumulated observations and experience over time, is significant for sustainable environmental management in collaboration with modern scientific knowledge. A number of innovative policy initiatives are currently being implemented in New Zealand to enable indigenous Maori tribes and sub-tribes to rehabilitate and manage their local fisheries in accordance with customary values and practices. These policies are an important milestone from an historical perspective as they are meant to recognise and empower the role of Maori as Treaty partners. The fisheries management regime in New Zealand now provides for Maori representation at the local level within a co-management framework that enables local Maori communities to exercise their customary rights. These institutional arrangements have been crafted to facilitate Maori input, based on customary values and practices, to complement modern Western management practices for sustainable harvesting of marine resources. Nevertheless, the degree to which these initiatives constitute an adequate response to Maori Treaty aspirations is debatable. A major constraint in this respect is that the government is compelled to recognise the needs of other, economically and politically more dominant, non-Maori user-groups in allocating and managing access to fishery resources and the marine environment.  相似文献   
153.
In the UK for the period 1994-99, a broad range of environmental projects were given financial support through the European Agriculture Guidance and Guarantee Fund under the Objective 1 and Objective 5b programmes. This paper is concerned with the ex-post evaluation of these projects set within a Sustainable Development framework. The aim was to identify project types or characteristics that offered the greatest return on investment. A classification of six broad project types was adopted. The evaluation revealed that there were significant differences between individual projects with respect to the type and scale, and temporal and social distribution of the benefits they delivered. In particular, as well as delivering environmental and economic benefits, many projects made a significant contribution to the development of human and social capital. The paper concludes that it is possible to improve the basis for future project selection in order to maximise the returns on environmental investments in the context of sustainable development.  相似文献   
154.
Laboratory column experiments run for up to 13 days compared air sparging of groundwater contaminated by dissolved petroleum hydrocarbons in sterile and non-sterile aquifer sediments as well as uncontaminated sediments and groundwater. Loss of dissolved BTEX compounds in the contaminated columns was very rapid, occurring through volatilisation. The majority of the dissolved total organic carbon (TOC) persisted for much longer periods however. A direct comparison between losses from sterile and non-sterile columns suggested a negligible contribution of biodegradation to the removal of TOC. This was difficult to confirm through examination of O2 utilisation because oxidation of a small amount of reduced sulphur in the aquifer materials was the dominant sink for O2. Despite this, it was possible to conclude that less than 22% of the removal of TOC was through biodegradation during the first three days of air sparging.  相似文献   
155.
/ This study intended to explore the perceptions of mountain bikingmanagement through a mail survey of state park directors in all 50 states.With a 100% response rate, it was found that 47 states permit mountainbiking in their state parks, however, few state parks have formalized plansto manage this outdoor activity. The management policies that do exist arenot followed on a statewide basis but vary within each state and at eachstate park. Many states have worked cooperatively with local mountain bikingclubs to develop and maintain mountain bike trails, promote rider education,and provide volunteer patrols on trails. The issue of user conflict surfacedwith almost three-fourths of the managers responding that conflict existedbetween mountain bikers and other trail users. This preliminary study shouldprompt further research with on-site managers focusing on the use ofmanagement plans for mountain biking, cooperation between managers and usergroups, and user conflict. It is recommended that an Internet-basedinformation clearinghouse or discussion group be made available to landmanagers by a national bicycling organization.KEY WORDS: Mountain biking; State parks; State park directors;Recreation resource management  相似文献   
156.
/ The risk tropospheric ozone poses to forests in the United States is dependent on the variation in ozone exposure across the distribution of the forests in question and the various environmental and climate factors predominant in the region. All these factors have a spatial nature, and consequently an approach to characterization of ozone risk is presented that places ozone exposure-response functions for species as seedlings and model-simulated tree and stand responses in a spatial context using a geographical information systems (GIS). The GIS is used to aggregate factors considered important in a risk characterization, including: (1) estimated ozone exposures over forested regions, (2) measures of ozone effects on species' and stand growth, and (3) spatially distributed environmental, genetic, and exposure influences on species' response to ozone. The GIS-based risk characterization provides an estimation of the extent and magnitude of the potential ozone impact on forests. A preliminary risk characterization demonstrating this approach considered only the eastern United States and only the limited empirical data quantifying the effect of ozone exposures on forest tree species as seedlings. The area-weighted response of the annual seedling biomass loss formed the basis for a sensitivity ranking: sensitive-aspen and black cherry (14%-33% biomass loss over 50% of their distribution); moderately sensitive-tulip popular, loblolly pine, eastern white pine, and sugar maple (5%-13% biomass loss); insensitive-Virginia pine and red maple (0%-1% loss). In the future, the GIS-based risk characterization will include process-based model simulations of the three- to 5-year growth response of individual species as large trees with relevant environmental interactions and model simulated response of mixed stands. The interactive nature of GIS provides a tool to explore consequences of the range of climate conditions across a species' distribution, forest management practices, changing ozone precursors, regulatory control strategies, and other factors influencing the spatial distribution of ozone over time as more information becomes available.KEY WORDS: Ecological risk assessment; GIS; Ozone; Risk characterization; Forests; Trees  相似文献   
157.
/ The Galilee region on the northern edge of Israel constitutes more than 15% of the state's territory, supplies more than half of its drinking water needs, and is an important recreational resource and destination for Israelis. One of the main objectives of the plan for the Galilee was to devise a regional physical and economic development strategy for the years 1992-2007 that would arrest the trend of emigration of its residents, attract newly arrived immigrants to the region, and at the same time protect natural resources and environmental quality. This paper is limited to discussion of the environmental aspects of the plan. It analyzes spatial concepts for distribution of projected population growth, evaluates environmental impacts of alternative plans, and proposes a decision-making framework and tools for minimizing natural resources loss from development at the local level. Assessment of potential environmental impacts generated quantitative data of natural resources areas. Application of the data in the plan evaluation stage showed that the alternative that concentrated most of the new development in central Galilee was the second-best choice environmentally, but was preferred as the best choice for overall qualities. The planning study offers an alternative environmental impact assessment (EIA) process to the one presently used in Israel by incorporating environmental considerations at the initial plan-making stage and not at the plan-approval stage. It demonstrated that in order to be effective, environmental assessment and land-use planning should be seen as one effort that is integrated from the start and in each stage of the plan-making process.KEY WORDS: Environmental assessment; Development planning; Galilee  相似文献   
158.
159.
ABSTRACT: Evidence is presented that snowmelt runoff from an urban watershed can produce density current intrusions (underflows) in a lake. Several episodes of density current intrusions are documented. Water temperatures and salinities measured near the bottom of a 10 m deep Minneapolis lake during the late winter warming periods in 1989, 1990, 1991, and 1995 show significant rapid changes which are correlated with observed higher air temperatures and snowmelt runoff. The snowmelt runoff entering this particular lake (Ryan Lake) has increased electrical conductivity, salinity, and density. The source of the salinity is the salt spread on urban streets in the winter. Heating of littoral waters in spring may also contribute to the occurrence of the sinking flows, but is clearly not the only cause.  相似文献   
160.
This study examined employers′ perceived knowledge of the Hazard Communication Standard (HCS) requirements prior to the inspection in which they were cited for an HCS violation. A lack of staff available to implement the HCS program was identified as having a significant impact upon compliance (p < 01). The perceived difficulty with compliance was also examined by the violations received by the organization. Those organizations cited for failing to have a written program identified a lack of staff available to implement the HCS requirements as having a greater impact upon compliance than those not cited for written program violations (p < 05). Suggested methods for improving the overall compliance with the HCS may include using the many compliance resources available through insurance companies, safety organizations, and state programs. Areas for further research include identifying the availability, use, and effectiveness of the outside safety and health compliance resources.  相似文献   
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