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301.
ABSTRACT: Integrated watershed ecosystem studies in National Parks or equivalent reserves suggest that effects of external processes on “protected” resources are subtle, chronic, and long-term. Ten years of data from National Park watersheds suggests that temperature and precipitation changes are linked to nitrogen levels in lakes and streams. We envision measurable biotic effects in these remote watersheds, if expected climate trends continue. The condition of natural resources within areas set aside for preservation are difficult to ascertain, but gaining this knowledge is the key to understanding ecosystem change and of processes operating among biotic and abiotic ecosystem components. There is increasing evidence that understanding the magnitude of variation within and between such processes can provide an early indication of environmental change and trends attributable to human-induced stress. The following four papers are case studies of how this concept has been implemented.* These long-term studies have expanded our knowledge of ecosystem response to natural and human-induced stress. The existence of these sites with a commitment to gathering “long-term” ecosystem-level data permits research activities aimed at testing more important hypotheses on ecosystem processes and structure.  相似文献   
302.
This article examines instrumental climate records from a varietyof stations associated with the following Biosphere Reserves across Canada: (i) Waterton Lakes, (ii) Riding Mountain, (iii) Niagara Escarpment, (iv) Long Point, and (v) Kejimkujik (Candidate Biosphere Reserve). Annual series are generated fromdaily temperature and precipitation values. In addition, homogeneous data are used from other stations and regional records to supplement the records from the local biosphere stations. Long term trends are identified over the period of the instrumental record. In general, data from the interval 1900 to 1998 show cooler temperatures in the 1920's, warmingfrom the early 1940's into the early 1950's, cooling into the1970's, and subsequent warming. At many stations, 1998 is the warmest in the instrumental record. Comparisons with the regional data sets show good agreements between the temperatureseries. The 20th century warming is approximately 1.0 °C in the Riding Mountain area and 0.6 °Cin the Long Point, Niagara Escarpment, and Waterton Lakes areas.There has been slight cooling in the Kejimkujik area over the past half century. Precipitation data show increasing trends inthe Kejimkujik, Long Point, Niagara Escarpment, and Waterton Lakes areas with no long term trend in the Riding Mountain area. This work is part of the Canadian Biosphere Reserves Association (CBRA) Climate Change Initiative (CCI), designed to present climate change information to Biosphere Reserve communities to allow local organizations to understand climate change and adapt to potential impacts.  相似文献   
303.
试论衡水湖湿地生态旅游开发   总被引:1,自引:0,他引:1  
衡水湖国家级自然保护区不仅具有丰富的生物多样性、优美的自然风光,还有悠久的历史文化,具备开展生态旅游得天独厚的先决条件。本文初步探讨了衡水湖开展湿地生态旅游的优势和原则。  相似文献   
304.
After almost two decades of decline, Ghana's mineral sector has rebounded significantly and is currently the main foreign exchange earner. Gold mining is the principal activity within the sector and accounted for 41 percent of total export earnings in 1996. This paper presents an overview of Ghana's mineral industry and covers mineral resources, production and reserves; mining investments; the role of mining in the economy; and the structure of the industry. An overview of the national mineral policy is also presented to depict the current regulatory and fiscal environment in which the industry operates. The spectacular reversal in mineral sector performance can be attributed to the adoption of World Bank recommendations in a new national mineral policy, the 1986 Minerals and Mining Law, aimed at revitalizing the sector.  相似文献   
305.
Methodological approaches to the construction of phytoecological maps are described regarding specially protected nature areas and their specific features. Such maps offer new possibilities for the assessment and analysis of current and predicted states of vegetation.  相似文献   
306.
Through shifts toward interactive and participatory forms of environmental governance, knowledge dynamics may come into play that differ from those of traditional forms of policy-making. This paper investigates how shifts of environmental governance and knowledge are related. In order to do so, it reconstructs the development of the governance of recreational boating in the Dutch Wadden Sea on the empirical basis of interviews, document analysis, and a focus group. Moreover, it analyzes this development by means of an analytical framework that combines governance modes, knowledge systems and knowledge–governance interfaces. Our results show that in the last decades partly an accumulation and partly a sequence of various governance arrangements concerning recreational boating has occurred; this has entailed a shift from predominantly centralized governance to a combination of governance modes with a stronger emphasis on decentralized, interactive and self-governance. This shift has occurred together with an increasing prominence of qualitative local knowledge, stakeholders’ knowledge, and the integration of various forms of knowledge. Furthermore, a shift has taken place toward more participatory knowledge–governance interfaces. Our analysis suggests that environmental governance and knowledge are interconnected in various ways: the regulatory and epistemic aspects of environmental issues are bound up with each other, and governance and knowledge are coproduced and mutually constitutive. Key lessons from this analysis are that room for experimentation is an important factor in improving environmental governance, and that increasing stakeholder involvement in governance implies that new modes of jointly creating and exchanging knowledge may need to be taken into account.  相似文献   
307.
Rural areas face increasing pressures to deliver both private and public goods from land management. Multiple stakeholders seek different outcomes and there is substantial heterogeneity in values. Trade-offs, synergies and complementarities exist between different services and alternative bundles of goods. The resulting complex social-ecological systems (SES) therefore require adaptive co-management. In a governance context, no single organisation has oversight across the variety of interests involved, but the challenge remains as to how these interests can best be balanced and negotiated, to deliver socially beneficial outcomes. This paper analyses how this might be achieved by considering the perspective of a ‘social residual claimant’ (SRC). The SRC, as an ideal type, represents the ultimate ‘owner’ or steward of an ecosystem which sets the criteria to assess alternative outcomes, identifying best approaches and addressing uncertainty through adaptive management. A SRC cannot be a static construct, but must interact with and influence private land-holders and other stakeholders, adjusting actions as circumstances change. We identify the criteria that would be required in order for an SRC to act in the best interests of society. We then make a comparison of these criteria against the conditions applying in three contrasting approaches currently operating in the UK: National Parks, Landscape Partnerships and Nature Improvement Areas. This enables us to identify the differences between approaches and to suggest changes that could enhance capabilities, as well as ideas for further research. We suggest that the ideal of an SRC offers a simple method of benchmarking that has potential application across a wider range of different local contexts, beyond the UK.  相似文献   
308.
Humans will continue to adapt to an increasingly technological world. But are there costs to such adaptations in terms of human well being? Toward broaching this question, we investigated physiological effects of experiencing a HDTV quality real-time view of nature through a plasma display “window.” In an office setting, 90 participants (30 per group) were exposed either to (a) a glass window that afforded a view of a nature scene, (b) a plasma window that afforded a real-time HDTV view of essentially the same scene, or (c) a blank wall. Results showed that in terms of heart rate recovery from low-level stress the glass window was more restorative than a blank wall; in turn, a plasma window was no more restorative than a blank wall. Moreover, when participants spent more time looking at the glass window, their heart rate tended to decrease more rapidly; that was not the case with the plasma window. Discussion focuses on how the purported benefits of viewing nature may be attenuated by a digital medium.  相似文献   
309.
Lands that have become unusable because of contamination with long-lived artificial radionuclides require special measures aimed at their monitoring and rehabilitation. In such areas, specific processes in the biota are associated with the direct effect of ionizing radiation on some species, secondary changes depending on the ecology of organisms trophically connected with these species, and side effects explained by the regime of isolation established in radiation reserves. The dynamics of floras and faunas in radiation reserves are determined by successional changes in plant communities, migration of radionuclides, and the protective status of these territories.  相似文献   
310.
通过对湖南省绥宁县黄桑自然保护区的植物群落特征及物种多样性的分析,结果表明:1)可将黄桑自然保护区的滩地、撂荒地和山坡地划分为3种群落类型:鱼腥草-蕨群丛、早熟禾-井栏边草群丛和杉木+马尾松-三尖杉+水苏-莎草+地稔群丛;2)植物多样性指数的大小顺序为:Patrick丰富度指数(R)、Simpson指数(D)和ShannonWiener指数(H)的大小顺序为:山坡地(S,D,H)撂荒地(S,D,H)滩地(S,D,H),Pielou均匀度指数(E)的大小顺序为:潍地(E)撂荒地(E)山坡地(E);3)3种样地之间的物种Czekanowski相似性系数(CC)较低,在0.0001~0.356 8之间,样地内的物种相似性指数(CC)沿滩地→撂荒地→山坡地的顺序递减;(4)相关分析表明:S、D、H之间呈极显著正相关(P0.01),E与S、D、H呈显著负相关(P0.05).生境条件差异是物种多样性差异形成的直接原因.表3,参16.  相似文献   
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