首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 0 毫秒
1.
To build the artificial forest ecosystem is the major eco-economic development model in the watershed of Miyun Reservoir. It is very important to evaluate the benefits of those ecosystems. Emergy theories are very helpful for us to establish a science-based assessment framework. Emergy evaluation of the artificial forest ecosystems in the watershed of Miyun Reservoir is used to asses the relative values of several ecological functions (sometimes called ecosystem services) and main ecosystem storages (sometimes called natural capital). The main driving energies, internal processes and storages are evaluated. The main functions, including transpiration, GPP and infiltration, are evaluated, which are 609em$/ha/yr, 6,245em$/ha/yr and 340em$/ha/yr respectively. The total values of major environmental services are 4,683em$/ha/yr in the artificial forest ecosystem. The main storages of natural capital including live biomass, soil moisture, organic matter, underground water and landform are estimated, which are 112,028em$/ha, 9em$/ha, 40,718em$/ha, 34em$/ha and 6,400,514em$/ha respectively. The largest value is landform, which accounts for 97.7% of these calculated total emdollar values. The concept of replacement value is explored using the emergy values of both ecosystem services and natural capital. The total calculated replacement values are 302,160em$/ha.  相似文献   

2.
Many of today's fish stocks are officially managed following the precautionary approach. Yet, different political objectives and uncertainties among fishermen about their economic future make its implementation difficult. Over 75% of all commercially valuable stocks are exploited, overused, or collapsed and in a state of recovery [FAO, 2004. The state of the world fisheries and aquaculture. FAO, Rome. Managing fish stocks with an ecosystem-based approach is likely to stop the divestment of natural capital by combining sustainable use strategies with the preservation of marine ecosystems. Using the example of the Baltic Sea cod fishery, we show that a recovery program is economically and ecologically viable and reduces negative externalities. While policy makers must assist fishermen during the early years of the program, fishermen will experience greater landings and profits in subsequent years.  相似文献   

3.
By their direct effects on private profitability, invasive agricultural pests create special incentives for management that set them apart from other categories of invasive species. One attractive nonchemical management approach for agricultural pests relies upon biological control by natural enemies. By improving the habitat of natural enemies of invasive agricultural pests, biological pest control can become privately attractive. This study develops a spatial optimization model to explore economically optimal spatial configuration of natural enemy habitat in agricultural landscapes. The model is applied to the management of soybean aphid (Aphis glycines), a recent invasive pest species of soybean production systems in the North Central region of the United States. Results indicate that non-crop habitat management can be a promising pest management option for organic cropping systems. Under current prices, however, habitat management tends to reduce net returns for conventional farms. Both area and configuration of non-crop habitats affect economic performance, with the greatest value coming from small, scattered areas of habitat.  相似文献   

4.
1. Introduction Ecosystem services are explicitly defined as “the natural environmental conditions and effects upon which people rely for existence that are formed and maintained by ecosystems and ecological processes” [1] . The valuation of ecosystem goods and services has become an important issue in the field of envi- ronmental protection and sustainable development, which also represents one aspect of the United Na- tions Millennium Assessment. At present, the re- search associated wit…  相似文献   

5.
6.
7.
Growth management and housing prices: the case of Portland, Oregon   总被引:3,自引:0,他引:3  
Portland, Oregon, is well known for its relatively unique urban growth boundary (UGB), a very tight form of zoning designed to control sprawl. The UGB has recently been criticized for raising housing prices. From a theoretical perspective, the UGB will put upward pressure on land and thus housing prices, but the magnitude of this effect is uncertain. Increasing density should substitute for higher land prices, partially offsetting any reduction in the supply of housing. In addition, at any given moment, speculative factors influence housing price levels in bull markets such as the one Portland has been experiencing. This article presents an econometric analysis assessing these conflicting effects. We find the UGB has created upward pressure on housing prices, but the effect is relatively small in magnitude.  相似文献   

8.
9.
10.
11.
In order to pursue informed stabilization policies, it is vital for policy-markers to have estimates of how much of the total unemployment rate can be classified as cyclical rather than natural unemployment. This paper describes a method for generating regional natural-rate estimates and applies this method to the case of Canadian provinces. Results indicate that unemployment insurance generosity and relative minimum wages play an important role in determining natural unemployment rates in Canadian provinces. One of the enduring characteristics of the Canadian labour market has been substantial and peresistent unemployment rate disparities across provinces. The results of this study indicate that these disparities are primarily explained by differences in provincial values of structural variables such as unemployment generosity and by differences in provincial sensitivities to these structural variables. A furher result is that variation in cyclical unemployment rates is substantially less in the traditionally high unemployment region of Atlantic Canada than it is in the traditionally low unemployment province of Ontario. This result implies that the most appropriate policies to reduce unemployment in Atlantic Canada are not regionally-applied expenditure policies but rather policies designed to reduce structural distortions in the provincial labour markets.  相似文献   

12.
13.
劳工短缺现象已成为东亚许多国家的普遍问题。这个问题并不是经济自发调节便可消除的暂时现象,如长期持续下去,将对各国的产品出口以及经济发展构成严重的制约。韩国自20世纪80年代末起便开始了对劳工短缺问题的调查研究,积累了大量的文献与实践经验。在描述韩国劳工短缺现状的基础上,探讨其成因并介绍韩国政府对此问题所采取的措施及实施效果。提出了对解决我国劳工短缺问题的可借鉴之处。  相似文献   

14.
Load management programs are used by electric utilities to decrease peak consumption. Although they are generally offered simultaneously with regular service, economic models of their allocative efficiency are based on the implicit assumption that they are the only service available. We present a model in which participation to a particular load management program, called self-rationing, is optional. We show that, under a break-even constraint, welfare-maximizing prices involve a subsidy from the self-rationing program to regular service whenever peak demand is less elastic than base demand. If cross-subsidization is precluded, regular service is viable only if there exist transaction costs to participate in the self-rationing program.  相似文献   

15.
《Ecological Economics》2001,36(1):45-60
In tropical and subtropical countries a social gradient can be observed in mountainous regions between small-scale farmers on fragile ecosystems associated with human poverty, and the fertile plains and broad valleys with large-scale cash crop productions and industrial centers associated with relative economic welfare. Sustainable community development paths have to be identified in these less privileged regions. The objective of this study was to make a contribution for defining and assessing development indicators at community level, including ecological, economic and social dimensions, to elicit the conflicting objectives in development and to discuss some practical implications. The study was performed in a typical watershed in central Honduras and special attention was given to autochthonous and qualitative indicators for development. Using the pressure-state-response model as a framework, a series of indicators were identified and assessed, which were also used by the local population and grouped into landscape structure, soil fertility, water availability and quality, production system and extractive activities, economic and social performance, and institutions. The development path in this specific case illustrated the transition from an expansive forest conversion agriculture to an intensified and diversified agriculture. This was made possible through technology transfer and improved market access. However, this development path, while increasing economic welfare, generated increasing negative environmental impacts caused by pesticide residues, soil erosion and less regular water supply. As the watershed carrying capacity for traditional shifting cultivation (used as a system indicator) reached its ecological limit, new sustainable development strategies had to be identified. The implications of the study for policy design are that tools need to be provided for natural and environmental resource monitoring, which may consist of sustainability goal definitions, a minimal set of indicators and simple maps for planning land use at local level.  相似文献   

16.
In this research, we use the concepts of “national technology policy” as well as the “firm technology strategy” in defining a new definition for “national technology strategy”. Then, by examining several national technology strategies in a variety of fields in different countries the national nanotechnology strategy for Iran is developed. Furthermore, using capability-effectiveness matrix and SWOT analysis we identify strategies of nanotechnology development in Iran. Finally, considering other countries' strategies and the results of PROMETHEE Method, we prioritize different areas of nanotechnology for Iranian economy, and test for the validity of the extracted strategies.  相似文献   

17.
The severe consequences of a Critical Infrastructure (CI) crisis demand continued research directed toward proactive and reactive management strategies. Despite the best efforts of governments and communities, the diversity of stakeholders, conflicting demands for resources, and a lack of trust among organizations create complexities that limit the effectiveness of the response. This paper identifies four specific problems that appear to reoccur when CIs are challenged: heterogeneity, multiple and inconsistent boundaries, resilience building and knowledge transfer and sharing. A combination of collaborative modeling and software simulation methodologies is proposed in order to identify the interrelationships among diverse stakeholders when managing the preparation for and reaction to a CI crisis. This approach allows experts to work together and share experiences through the modeling process which can lead them to a better understanding of how other organizations work and integrate different perspectives. In addition, simulation models enable domain experts to understand the consequences of certain policies in the short and long terms, thus improving the crisis managers' knowledge for future crisis situations. This paper presents a practical case of a hypothetical crisis in the CI sector and the approach used in order to deal with the four problems identified above.  相似文献   

18.
In recent years, more and more conflicts have emerged in the management of nature reserves, of which themain problem is that how to carry out the campaign of conservation along with the promotion of development of localeconomics. To resolve the actual problem in Nanjishan National Wetland Nature Reserve and explore the idiographicmethod of the management of the wetland reserve, some studying methods including face-to-face interviews, informaldiscussion with local leaders and officials, group discussion with local fishers, questionnaire, and job of the conversationstation have been carried out. The results show that the education level of the local people is low; only 5% of the localpeople have an opportunity to the junior college; the main income of the local people is fishing, which accounts for 70%more or less; and the income is coming down year by year because of the unreasonable way of fishing. To cope with theproblems, some reformative way of management and the development of the reserve are introduced, such as establishingan NOG that constitutes of local fishermen to achieve the goal of community co-management, developing Bed andBreakfast and so on. Through practice of the management of the participation of the local people, we draw the conclusionthat the local people have a great desire to improve their life level, and to make the co-management of the reserve easy,it is important for the managers to play the role of pilot including engrafting the new ideas, giving some subsidy toencourage the local people to take part in the management. In addition, making local people perceive value of the reserveand the close relation between reserve conservation and the promotion of level of their life. On this basis, they incline totake part in the management of the reserve.  相似文献   

19.
One logical implication of the Darwinian hypothesis of ‘survival of the fittest’ is that animals exhibit optimizing behavior. Surprisingly, this has not been included in the resource economics literature. This paper explores the implications of optimizing behavior in a model where moose face migration decisions and humans wish to keep moose out of an area to protect young pine trees. The results show that if moose are rational, a given hunting effort will lead to better outcomes for humans than if the moose only focus on harvesting opportunities. This finding suggests that the validity of the standard assumption that animal migration behavior is density-dependent should be re-examined.   相似文献   

20.
In participatory technology assessment (pTA), technical and nontechnical communities convene to share their views on a sociotechnical challenge, in an attempt to render technology research and development more socially robust. Taking these commitments to transdisciplinary collaboration and co-construction of technology as entry points, this article describes key tensions that emerged in a Flemish pTA project on nanotechnologies, entitled ‘Nanotechnologies for Tomorrow's Society’ (NanoSoc). The tensions relate to how the terms of participation were enacted, the potentially conflicting aims embedded in the project's mission and methods, the various roles initiating pTA researchers (social scientists) assumed throughout the project's duration, and the deliberative-democratic rationale that sustains pTA frameworks at large. The article is a response to a pressing question posed to the author by pTA professionals, project participants and policymakers who ask publics to partake in science and technology decision making: now that NanoSoc is concluded, what can we learn from it?  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号