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461.
Abstract:  Ecosystem management was formally adopted over a decade ago by many U.S. natural resource agencies, including the Forest Service and the Bureau of Land Management. This approach calls for management based on stakeholder collaboration; interagency cooperation; integration of scientific, social, and economic information; preservation of ecological processes; and adaptive management. Results of previous studies indicate differences in the extent to which particular components of ecosystem management would be implemented within the U.S. Forest Service and the Bureau of Land Management and suggest a number of barriers thought to impede implementation. Drawing on survey and interview data from agency personnel and stakeholders, we compared levels of ecosystem-management implementation in the Forest Service and Bureau of Land Management and identified the most important barriers to implementation. Agency personnel perceived similarly high levels of implementation on many ecosystem-management components, whereas stakeholders perceived lower levels. Agencies were most challenged by implementation of preservation of ecological processes, adaptive management, and integration of social and economic information, whereas the most significant barriers to implementation were political, cultural, and legal.  相似文献   
462.
三“S”一体化技术在林火灾害监测中的应用初探   总被引:3,自引:0,他引:3  
遥感(RS)、地理信息系统(GIS)、全球定位系统(GPS)技术在自身进一步发展的同时,正日益朝集成化、一体化方向迈进。“3S技术”一体化为林火灾害监测提供了新的极具潜力的技术支持。本文从“3S技术”一体化角度,探讨了它在未来林火监测中应用的可能性及应用模式,最后提出了建立全国林火遥感监测系统的总体设想。  相似文献   
463.
王保乾 《环境技术》2000,18(2):2-8,26
本文简述运输环境和试验条件的制订对模拟运输试验的各种方法作了简单评述,尤其是对利用电子--液压振动台对大型整体产品在悬臂梁状态的试验作了介绍。最后说明一种能模拟带有高峰值随机振动的试验技术,以改进现有数控设备的不足。  相似文献   
464.
乌苏里江国家森林公园开发建设探讨   总被引:2,自引:0,他引:2  
介绍了乌苏里江国家森林公园旅游资源概况 ,在确定公园开发建设原则的基础上 ,评价了公园的开发建设条件 ,并提出了公园开发建设措施。  相似文献   
465.
Towards a sustainable Russian forest sector   总被引:4,自引:0,他引:4  
Russia's forest resources are enormous, but despite almost ten years of transition, problems are still immense, in terms of commercial output and with respect to forest management. This article suggests that one way of changing the situation is to introduce community management of forests. Using the Swedish forest commons as an example, this article argues that such a change in property rights will provide an alternative to massive privatization of the forests and to the undesirable continuation or strengthening of state forest management. Finally, it is concluded that such an introduction of new property rights regimes will not provide the solution to the problems, but rather will contribute to the establishment of a better institutional framework in the Russian forest sector.  相似文献   
466.
研究气候变化下林地植被生态需水量的时空变化,对于保护涵养水源的林地植被系统,合理规划管理流域水资源有着重要作用。以汉江上游流域11个气象站点1971~2010年的气象资料为依据,采用结合[1]土壤含水量与植物类型修正蒸散发量得到植被生态需水量的方式,从时空角度定量研究了在生长季4~10月份流域林地植被生态需水量及其趋势性变化,并且分析了生态需水量对各气象因子变化的敏感性程度。结果表明:汉江上游流域林地植被多年平均生长季生态需水量为6.915 8×109 m3,整体上呈现非显著性增加趋势,在空间分布上具有明显的地带性特征。生态需水量对不同气象因子有不同程度的敏感性:最高温度水汽压太阳辐射风速最低温度,生态需水量对各气象因子敏感程度的地带性分布特征还与各区域的纬度、海拔、植被类型和下垫面情况有关。  相似文献   
467.
Until the 20th century, forest policies across the globe focused primarily on effective forest utilization for timber production. Subsequent loss of forest land prompted many countries to review and amend such policies, in an attempt to incorporate the principles of conservation and sustainable forest management. One of the countries to implement such changes was India, which introduced new policies, acts and programmes to regulate forest conversion and degradation, beginning in the 1980s. These policies, acts, and programmes included the Forest Conservation Act of 1980, the National Forest Policy of 1988 and the Hon. Supreme Court Order of 1996. All of these regulations affected the timber supply from government forest areas, and created a huge gap in timber supply and demand. Currently, this deficit is met through imports and trees outside forests (TOFs). Timber production from government forest areas is abysmally low (3.35% of total demand) compared to potential timber production from TOFs, which fulfil 45% of the total timber demand in India. This implies that TOFs have immense potential in meeting the growing timber demand; however, they have not been fully utilized due to discrepancies in state level TOFs’ policies. The present paper provides a review of different forest policies, acts and guidelines in relation to timber production in India, and provides specific recommendations in order to maximize timber production in the context of increasing demand for timber products.  相似文献   
468.
India's forest biodiversity management regime is analysed at the policy, legal and institutional levels, from the perspective of the triple objectives of the Convention on Biological Diversity and the principles of the Indian constitution. The forest biodiversity management regime has both structural and functional flaws that render it largely incapable of facing the challenge of increasing biodiversity degradation and deepening poverty among the Adivasis and other forest‐dependent communities. The paper argues for the reform of the forest biodiversity management regime and offers recommendations in regard to most aspects of the regime, with a view of putting the country's conservation enterprise on a course that is effective, sustainable and inclusive, rejecting the report of the High Power Committee (HPC) (also known as the Subramanian Committee), which is premised on easing corporate access to forests.  相似文献   
469.
Climate change incurs costs, but government adaptation budgets are limited. Beyond a certain point, individuals must bear the costs or adapt to new circumstances, creating political-economic tipping points that we explore in three examples. First, many Alaska Native villages are threatened by erosion, but relocation is expensive. To date, critically threatened villages have not yet been relocated, suggesting that we may already have reached a political-economic tipping point. Second, forest fires shape landscape and ecological characteristics in interior Alaska. Climate-driven changes in fire regime require increased fire-fighting resources to maintain current patterns of vegetation and land use, but these resources appear to be less and less available, indicating an approaching tipping point. Third, rapid sea level rise, for example from accelerated melting of the Greenland ice sheet, will create a choice between protection and abandonment for coastal regions throughout the world, a potential global tipping point comparable to those now faced by Arctic communities. The examples illustrate the basic idea that if costs of response increase more quickly than available resources, then society has fewer and fewer options as time passes.  相似文献   
470.
Abstract

The distribution and persistence of aerially applied mexacarbate were studied in a New Brunswick aquatic forest environment after spraying twice at a dosage of 70 g A.l./ha using a fixed‐wing aircraft. Average droplet density (drops/cm2) and ground deposition (g A.1./ha) between the two applications differed considerably. The values for the first and second applications were 1.7 and 0.73, and 5.2 and 2.0, respectively; but the average NMD (20 μm) and VMD (36 μm) for both applications were nearly the same. The maximum 1‐h postspray concentrations of mexacarbate in the stream and pond waters were 0.73 and 18.74 ppb, respectively. Concentrations fell rapidly to below detection limits within 12 h in stream and within 3 d in pond water. Cattails (Typha latifolia), manna grass (Glyceria borealis) and bog moss (Sphagnum sp.) collected from the pond contained peak 1‐h postspray concentrations of 720, 482 and 81 ppb, respectively. The concentration levels decreased rapidly and the average half‐lives of the chemical in them were about 3.9, 8.5 and 2.0 h. Bog moss, stream moss (Fontinalis sp.), watercress (Nasturtium officinalis), buttercup (Ranunculus aquatilis) and green alga (Drapamaldia sp.) sampled from the stream sites did not contain measurable levels of mexacarbate. Also, caged and wild tadpoles (Rana clamitans melanota) from the pond, and brook trout (Salvelinus fontinalis) (caged and wild), Atlantic salmon (Salmo salar) (wild) and mayfly nymphs (Ephemeralla sp.) collected from the stream did not contain any of the material. Mexacarbate was not detected in stream and pond sediments. The demethylated products, 4‐methylamino and 4‐amino‐3,5‐xylyl methylcarbamates and the phenol, 4‐dimethylamino‐3,5‐xylenol, were frequently detected as metabolites in water and in the aquatic plants. The presence of these compounds showed that demethylation and hydrolytic routes are the major metabolic pathways for the dissipation of mexacarbate from these substrates.  相似文献   
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