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We conducted case studies of three successful examples of collaborative, community-based natural resource conservation and development. Our purpose was to: (1) identify the functions served by interactions within the social networks of involved stakeholders; (2) describe key structural properties of these social networks; and (3) determine how these structural properties varied when the networks were serving different functions. The case studies relied on semi-structured, in-depth interviews of 8 to 11 key stakeholders at each site who had played a significant role in the collaborative projects. Interview questions focused on the roles played by key stakeholders and the functions of interactions between them. Interactions allowed the exchange of ideas, provided access to funding, and enabled some stakeholders to influence others. The exchange of ideas involved the largest number of stakeholders, the highest percentage of local stakeholders, and the highest density of interactions. Our findings demonstrated the value of tailoring strategies for involving stakeholders to meet different needs during a collaborative, community-based natural resource management project. Widespread involvement of local stakeholders may be most appropriate when ideas for a project are being developed. During efforts to exert influence to secure project approvals or funding, however, involving specific individuals with political connections or influence on possible sources of funds may be critical. Our findings are consistent with past work that has postulated that social networks may require specific characteristics to meet different needs in community-based environmental management. 相似文献
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The toxicity of an organotin pesticide, triphenyltin hydroxide, was assessed with several freshwater cladoceran species. Daphnia pulex, Daphnia magna, and Ceriodaphnia dubia were exposed for 48 h to triphenyltin hydroxide in static acute toxicity tests. Values of the 48-h trimmed Spearman-Karber EC(50)s for the three species were found to be 14.5, 16.5, and 11.3 microg litre(-1), respectively. Analysis of variance performed on EC(50) values of replicates revealed no significant differences between the three species. Methods were employed which decrease animal handling stress and increase the accuracy and precision of the concentrations. 相似文献
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As complex social phenomena, public involvement processes are influenced by contextual factors. This study examined agency
goals for public involvement and assessed the importance of local context in remedial action planning, a community-based water
resources program aimed at the cleanup of the 42 most polluted locations in the Great Lakes Basin. Agency goals for public
involvement in remedial action plans (RAPs) were agency-oriented and focused on public acceptance of the plan, support for
implementation, and positive agency-public relations. Corresponding to these goals, citizen advisory committees were created
in 75% of the RAP sites as a primary means for public input into the planning process. Factors that influenced the implementation
of public involvement programs in remedial action planning included public orientation toward the remediation issue, local
economic conditions, the interaction of diverse interests in the process, agency and process credibility, experience of local
leadership, and jurisdictional complexity. A formative assessment of “community readiness” appeared critical to appropriate
public involvement program design. Careful program design may also include citizen education and training components, thoughtful
management of ongoing agency-public relations and conflict among disparate interests in the process, overcoming logistical
difficulties that threaten program continuity, using local expertise and communication channels, and circumventing interjurisdictional
complexities. 相似文献
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Acute and chronic toxicity of triphenyltin hydroxide to fathead minnows (Pimephales promelas) following brief or continuous exposure 总被引:1,自引:0,他引:1
Jarvinen AW Tanner DK Kline ER Knuth ML 《Environmental pollution (Barking, Essex : 1987)》1988,52(4):289-301
Fathead minnow larvae (Pimephales promelas) were exposed to triphenyltin hydroxide (TPTH) during brief (single pulse) or continuous exposure in 96-h and 30-day toxicity tests. The continuous exposure 96-h LC(50) value was 7.1 microg litre(-1). Brief exposures for 12 to 72-h gave 96-h LC(50) values that ranged from 61.8 to 6.0 microg litre(-1), respectively. The continuous exposure 30-day chronic effect concentration, based upon reduced growth, was 0.23 microg litre. Survival was significantly reduced at 2.0 microg litre(-1). Brief exposures for 24, 48, and 72-h in 30-day tests significantly reduced survival and growth at 13.0, 13.0 and 60.0 microg litre(-1) respectively. It is suggested that both toxicant concentration and exposure duration are important factors to consider in the risk assessment of potential pesticide hazards in the environment. 相似文献
7.
Invasions of nonnative species such as zebra mussels can have both ecological and economic consequences. The economic impacts
of zebra mussels have not been examined in detail since the mid-1990s. The purpose of this study was to quantify the annual
and cumulative economic impact of zebra mussels on surface water-dependent drinking water treatment and electric power generation
facilities (where previous research indicated the greatest impacts). The study time frame was from the first full year after
discovery in North America (Lake St. Clair, 1989) to the present (2004); the study area was throughout the mussels’ North
American range. A mail survey resulted in a response rate of 31% for electric power companies and 41% for drinking water treatment
plants. Telephone interviews with a sample of nonrespondents assessed nonresponse bias; only one difference was found and
adjusted for. Over one-third (37%) of surveyed facilities reported finding zebra mussels in the facility and almost half (45%)
have initiated preventive measures to prevent zebra mussels from entering the facility operations. Almost all surveyed facilities
(91%) with zebra mussels have used control or mitigation alternatives to remove or control zebra mussels. We estimated that
36% of surveyed facilities experienced an economic impact. Expanding the sample to the population of the study area, we estimated
$267 million (BCa 95% CI = $161 million–$467 million) in total economic costs for electric generation and water treatment
facilities through late 2004, since 1989. Annual costs were greater ($44,000/facility) during the early years of zebra mussel
infestation than in recent years ($30,000). As a result of this and other factors, early predictions of the ultimate costs
of the zebra mussel invasion may have been excessive. 相似文献
8.
We applied the Theory of Planned Behavior to help understand the relationships between environmental beliefs, support for
ecosystem restoration actions, and willingness to pay (WTP) for restoration and protection goals in the Hudson River estuary,
New York State, USA. We conducted a mail survey with 3,000 randomly-chosen local residents of the Hudson River estuary in
the fall of 1999. As hypothesized, the broad ecosystem restoration goals of the Hudson River Estuary Action Plan were more
strongly supported than the corresponding specific implementation actions. We found that beliefs and past behavior were better
explanatory variables than sociodemographic characteristics for explaining people's support for ecosystem restoration actions
and WTP for restoration and protection goals. Because ecosystem restoration goals appear to be more generally acceptable than
specific restoration actions, proponents of restoration programs should not become complacent about the need for active public
outreach and involvement even if initial restoration program discussions have been low in controversy. Efforts to assess and
foster support for ecosystem restoration should be targeted toward audiences identified on the basis of beliefs and past behaviors
rather than on sociodemographic characteristics. 相似文献
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Abstract While US climate change mitigation policy has stalled at the national level, local and regional actors are increasingly taking progressive steps to reduce their greenhouse gas emissions. Universities are poised to play a key role in this grassroots effort by targeting their own emissions and by working with other local actors to develop climate change mitigation programmes. Researchers at the Pennsylvania State University have collaborated with university administrators and personnel to inventory campus emissions and develop mitigation strategies. In addition, they have facilitated a stakeholder-driven climate change mitigation project in one Pennsylvania county and started an ongoing service-learning project aimed at reducing emissions in another county. These campus and community outreach initiatives demonstrate that university-based mitigation action may simultaneously achieve tangible local benefits and develop solutions to broader challenges facing local climate change mitigation efforts. Outcomes include improved tools and protocols for measuring and reducing local emissions, lessons learned about service-learning approaches to climate change mitigation, and methods for creating climate change governance networks involving universities, local governments and community stakeholders. 相似文献
10.
The United States Environmental Protection Agency (USEPA) Region V Clean Lakes Program employs artificial and modified natural
wetlands in an effort to improve the water quality of selected lakes. We examined use of wetlands at seven lake sites and
evaluated the physical and institutional means by which wetland projects are implemented and managed, relative to USEPA program
goals and expert recommendations on the use of wetlands for water quality improvement. Management practices recommended by
wetlands experts addressed water level and retention, sheet flow, nutrient removal, chemical treatment, ecological and effectiveness
monitoring, and resource enhancement. Institutional characteristics recommended included local monitoring, regulation, and
enforcement and shared responsibilities among jurisdictions. Institutional and ecological objectives of the National Clean
Lakes Program were met to some degree at every site. Social objectives were achieved to a lesser extent. Wetland protection
mechanisms and appropriate institutional decentralization were present at all sites. Optimal management techniques were employed
to varying degrees at each site, but most projects lack adequate monitoring to determine adverse ecological impacts and effectiveness
of pollutant removal and do not extensively address needs for recreation and wildlife habitat. There is evidence that the
wetland projects are contributing to improved lake water quality; however, more emphasis needs to be placed on wetland protection
and long-term project evaluation. 相似文献