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81.
Mortimer MJ 《Environmental management》2008,41(5):640-653
Political and legal conflicts between the need for targeted private forest conservation and the continued assurance of private
property rights in the U.S. presents a seemingly intractable resource management problem. Scandinavian use of habitat protection
areas on private forests offers an additional tool that may be suitable for solving the historical and on-going tension found
within U.S. efforts to reconcile desires to maintain lands in a forested condition while also respecting private property
rights. This article presents a comparative cross-sectional policy analysis of Sweden, Finland, and the U.S., supported with
a supplemental case example from the Commonwealth of Virginia. Similarities in all three countries among forest ownership
patterns, use of public subsidies, and changing attitudes towards conservation are generally encouraging. Additionally, Virginia’s
current consideration and development of state-wide forest policies focused on forestland and open space conservation suggests
both a need and an opportunity to systematically assess the applicability of the Nordic forest reserve approach to local private
forest conservation. Future research at a high-resolution, and specifically at the state level, should focus on the social
and political factors that would ultimately determine the viability of a forest reserve program. 相似文献
82.
The machair sand dune systems of the Outer Hebrides of Scotland are a unique habitat, which is rare within both a global and
European context. Unusually, the machair habitat also represents an agricultural resource that is very important to the Hebridean
people, having been subject to both grazing and cultivation throughout the historical period. Following designation as an
Environmentally Sensitive Area (ESA) in 1988, the machairs of South Uist have been studied with the aim of understanding the
links between agricultural practice and their plant community and ecosystem dynamics. This research focused primarily on the
effects of cultivation practices and their role in maintaining plant species richness and community and ecosystem stability.
Within two carefully selected areas, the successional plant communities of machair at different stages of recovery following
ploughing and cultivation of cereals and potato patches or ‘lazy beds’ were identified at both a macro- and micro-level. Investigations
of the vegetation recovery processes on turves taken from newly ploughed land indicated that the initial stages of recolonization
are characterized primarily by rapid vegetative reproduction and growth, although re-vegetation by seeds is also an important
factor. The implications of these findings for the long-term management of machair plant communities are discussed and in
particular the need to maintain old cultivation practices such as shallow ploughing. The need for more detailed research into
both seed banks and seed rain and into processes of vegetative reproduction is stressed.
Nomenclature: Clapham et al. (1981) and Stace (1991, 1997) for vascular plants; Hubbard (1984) for grasses; Pankhurst & Mullin (1991) for
the regional flora; Dobson (1992) for lichens; Watson (1981) for mosses and liverworts. 相似文献
83.
How conservation messages are framed will impact the success of our efforts to engage people in conservation action. This is highly relevant in the private land conservation (PLC) sector given the low participation rates of landholders. Using a case study of PLC schemes targeted at Australian landholders, we present the first systematic analysis of communication strategies used by organisations and government departments delivering those schemes to engage the public. We develop a novel approach for analysing the framing of conservation messages that codes the stated benefits of schemes according to value orientation. We categorised the benefits as flowing to either the landholder, to society, or to the environment, corresponding to the egoistic, altruistic and biospheric value orientations that have been shown to influence human behaviour. We find that messages are biased towards environmental benefits. Surprisingly, this is the case even for market-based schemes that have the explicit objective of appealing to production-focussed landholders and those who are not already involved in conservation. The risk is that PLC schemes framed in this way will fail to engage more egoistically oriented landholders and are only likely to appeal to those likely to already be conservation-minded. By understanding the frame in which PLC benefits are communicated, we can begin to understand the types of people who may be engaged by these messages, and who may not be. Results suggest that the framing of the communications for many schemes could be broadened to appeal to a more diverse group (and thus ultimately to a larger group) of landholders. 相似文献
84.
New York City’s extensive municipal park system is home to forests, wetlands, and grasslands that provide important ecological and social benefits to the city’s population. While efforts and programs exist to restore and protect these spaces, management recommendations are complex due to variable conditions in urban natural areas. To advance the management of urban natural areas, the first comprehensive ecological assessment was conducted through a collaborative effort across 4000 ha of natural areas within New York City parkland. Field and spatial data were collected and analyzed to identify the extent of forests, the types of forests, and their conditions. This approach will help guide decision-making and prioritization of natural area management at the regional level by developing unique quantitative targets for urban forests. This project serves as an example of collaboration between private and public institutions advancing the governance of urban natural areas to achieve citywide conservation and policy goals. 相似文献
85.
86.
Rethinking receiver operating characteristic analysis applications in ecological niche modeling 总被引:2,自引:0,他引:2
The area under the curve (AUC) of the receiver operating characteristic (ROC) has become a dominant tool in evaluating the accuracy of models predicting distributions of species. ROC has the advantage of being threshold-independent, and as such does not require decisions regarding thresholds of what constitutes a prediction of presence versus a prediction of absence. However, we show that, comparing two ROCs, using the AUC systematically undervalues models that do not provide predictions across the entire spectrum of proportional areas in the study area. Current ROC approaches in ecological niche modeling applications are also inappropriate because the two error components are weighted equally. We recommend a modification of ROC that remedies these problems, using partial-area ROC approaches to provide a firmer foundation for evaluation of predictions from ecological niche models. A worked example demonstrates that models that are evaluated favorably by traditional ROC AUCs are not necessarily the best when niche modeling considerations are incorporated into the design of the test. 相似文献
87.
Protected areas are integral to the global effort to conserve biodiversity, and, over the past two decades, protected area managers have begun to recognize that conservation objectives are next to impossible to achieve without considering the needs and concerns of local communities. Incentive-based programs (IBPs) have become a favored approach to protected area management, geared at fostering local stewardship by delivering benefits tied to conservation to local people. Effective IBPs require benefits to accrue to and be recognized by those experiencing the greatest consequences as a result of the protected area, and those likely to continue extractive activities if their livelihood needs are compromised. This research examines dispersal of IBP benefits, as perceived by local residents in Nepal's Annapurna Conservation Area. Results reported here are based on questionnaire interviews with 188 households conducted between September and December 2004. Results indicate that local residents primarily identify benefits from social development activities, provisions for resource extraction, and economic opportunities. Overall, benefits have been dispersed equally to households in villages on and off the main tourist route, and regardless of a household's participation in tourism. However, benefits are not effectively targeted to poorer residents, those highly dependent on natural resources, and those experiencing the most crop damage and livestock loss from protected wildlife. This article provides several suggestions for improving the delivery of conservation incentives. 相似文献
88.
Govil PK Sorlie JE Murthy NN Sujatha D Reddy GL Rudolph-Lund K Krishna AK Rama Mohan K 《Environmental monitoring and assessment》2008,140(1-3):313-323
Studies on quantitative soil contamination due to heavy metals were carried out in Katedan Industrial Development Area (KIDA),
south of Hyderabad, Andhra Pradesh, India under the Indo-Norwegian Institutional Cooperation Programme. The study area falls
under a semi-arid type of climate and consists of granites and pegmatite of igneous origin belonging to the Archaean age.
There are about 300 industries dealing with dyeing, edible oil production, battery manufacturing, metal plating, chemicals,
etc. Most of the industries discharge their untreated effluents either on open land or into ditches. Solid waste from industries
is randomly dumped along roads and open grounds. Soil samples were collected throughout the industrial area and from downstream
residential areas and were analysed by X-ray Fluorescence Spectrometer for fourteen trace metals and ten major oxides. The
analytical data shows very high concentrations of lead, chromium, nickel, zinc, arsenic and cadmium through out the industrial
area. The random dumping of hazardous waste in the industrial area could be the main cause of the soil contamination spreading
by rainwater and wind. In the residential areas the local dumping is expected to be the main source as it is difficult to
foresee that rain and wind can transport the contaminants from the industrial area. If emission to air by the smokestacks
is significant, this may contribute to considerable spreading of contaminants like As, Cd and Pb throughout the area. A comparison
of the results with the Canadian Soil Quality Guidelines (SQGL) show that most of the industrial area is heavily contaminated
by As, Pb and Zn and local areas by Cr, Cu and Ni. The residential area is also contaminated by As and some small areas by
Cr, Cu, Pb and Zn. The Cd contamination is detected over large area but it is not exceeding the SQGL value. Natural background
values of As and Cr exceed the SQGL values and contribute significantly to the contamination in the residential area. However,
the availability is considerably less than anthropogenic contaminants and must therefore be assessed differently. The pre-
and post-monsoon sampling over two hydrological cycles in 2002 and 2003 indicate that the As, Cd and Pb contaminants are more
mobile and may expect to reach the groundwater. The other contaminants seem to be much more stable. The contamination is especially
serious in the industrial area as it is housing a large permanent residing population. The study not only aims at determining
the natural background levels of trace elements as a guide for future pollution monitoring but also focuses on the pollution
vulnerability of the watershed. A plan of action for remediation is recommended. 相似文献
89.
Many species of conservation concern are spatially structured and require dispersal to be persistent. For such species, altering the distribution of suitable habitats on the landscape can affect population dynamics in ways that are difficult to predict from simple models. We argue that for such species, individual-based and spatially explicit population models (SEPMs) should be used to determine appropriate levels of off-site restoration to compensate for on-site loss of ecologic resources. Such approaches are necessary when interactions between biologic processes occur at different spatial scales (i.e., local [recruitment] and landscape [migration]). The sites of restoration and habitat loss may be linked to each other, but, more importantly, they may be linked to other resources in the landscape by regional biologic processes, primarily migration. The common management approach for determining appropriate levels of off-site restoration is to derive mitigation ratios based on best professional judgment or pre-existing data. Mitigation ratios assume that the ecologic benefits at the site of restoration are independent of the ecologic costs at the site of habitat loss. Using an SEPM for endangered red-cockaded woodpeckers, we show that the spatial configuration of habitat restoration can simultaneously influence both the rate of recruitment within breeding groups and the rate of migration among groups, implying that simple mitigation ratios may be inadequate. 相似文献
90.
从生态保护与管理的角度出发,综合分析了青藏高原生态屏障区近十年生态系统结构、服务功能、生态胁迫等生态环境变化特征,并提出生态保护对策与建议。结果表明,2000年-2010年屏障区生态系统结构稳定,其中城镇和湿地面积增加明显;生态系统服务功能整体上升,其中屏障区北部区域改善明显;生态胁迫以人口、GDP、载畜量等人类胁迫为主,自然胁迫整体较低;未来应继续加强基本草原保护,实施生态修复工程,不断提高屏障区的重要生态功能。 相似文献