樟子松人工防风固沙林放牧资源的初步分析

本文通过测定樟子松防风固沙林草地植物产量,对草本植物生物产量的季节动态及林分密度对草本植物产量的影响作了定性和定量分析。此外,还采用牧草产量法对章古台樟子松固沙林可牧资源生产潜力进行了初步评价。     

热带林业实验中心森林病虫害防治对策

林病虫害已成为林业发展的一大难题,对中国林科院热带林业实验中心森林病虫害类型、危害特点等进行分析,并提出了具体有效防治措施与方法.参6.     

浅析相关因子对空气负离子水平的影响

空气负离子是一种重要的森林旅游资源，其保健功能迎合了人们追求生态健康的旅游心理．论文着重对其影响因素进行分析，借助于SPSS统计软件对若干因子进行一元回归分析．在分析结果的基础上，对森林旅游地有关保健设施的规划和设计提供一定的建议。     

Effects of New Forestry Practices on Rare Epiphytic Macrolichens

Abstract:  The preservation of key habitats is included in modern forest-management practices as one of the main means to preserve biodiversity in northern European production forests. I examined the distribution patterns and persistence of occurrence of rare epiphytic macrolichens in a predominantly unprotected forest landscape with an area of 278 km² in southern Finland. Occurrence data of macrolichens in two key habitats, rock outcrops and mires, were compared with data from production forests. The density of populations of rare macrolichens was 50-fold higher on rock outcrops and 25-fold higher on mires than in production forests. Most rare species of epiphytic macrolichens were found only in key habitats. In modern, intensively managed forest landscapes, rock outcrops appeared to represent the main habitats for rare macrolichens as a result of the long-term continuity of old trees. Most macrolichen occurrences represented very small populations with a high extinction risk. Of the populations found in 1989–1995 in key habitats, 51% had disappeared, by 2000–2001, mainly as a result of forestry activities. The disappearance of populations significantly exceeded the rate of establishment of new populations. My results emphasize the importance of key habitats for declining forest species. There is also a need to improve and sharpen the guidelines for delimiting and managing key habitats in order to halt the continued decline of epiphytic macrolichens.     

Carbon Monitoring Costs and their Effect on Incentives to Sequester Carbon through Forestry

Technically, forestry projects have thepotential to contribute significantly tothe mitigation of global warming, but manysuch projects may not be economicallyattractive at current estimates of carbon(C) prices. Forest C is, in a sense, a newcommodity that must be measured toacceptable standards for the commodity toexist. This will require that credible Cmeasuring and monitoring procedures be inplace. The amount of sequestered C that canbe claimed by a project is normallyestimated based on sampling a number ofsmall plots, and the precision of thisestimate depends on the number of plotssampled and on the spatial variability ofthe site. Measuring C can be expensive andhence it is important to select anefficient C-monitoring strategy to makeprojects competitive in the C market. Thispaper presents a method to determinewhether a forestry project will benefitfrom C trading, and to find the optimalmanagement strategy in terms of forestcycle length and C-monitoring strategyA model of an Acacia mangiumplantation in southern Sumatra, Indonesiais used to show that forestry projects canbe economically attractive under a range ofconditions, provided that the project islarge enough to absorb fixed costs.Modeling results indicate that between 15and 38 Mg of Certified Emission Reductions(CERs) per hectare can be captured by thesimulated plantation under optimalmanagement, with optimality defined asmaximizing the present value of profitsobtained from timber and C. The optimalcycle length ranged from 12 to 16 years andthe optimal number of sample plots rangedfrom 0 to 30. Costs of C monitoring (inpresent-value terms) were estimated to bebetween 0.45 (Mg C)^-1 to 2.11 (MgC)^-1 depending on the spatialvariability of biomass, the variable costsof C monitoring and the discount rate.     

Prospects for mitigating carbon,conserving biodiversity,and promoting socioeconomic development objectives through the clean development mechanism

Should forest-based climate mitigationmeasures be approved for crediting through the CleanDevelopment Mechanism (CDM), they could offer anopportunity to accomplish three important objectives:cost-effective reductions in carbon emissions andsequestration of atmospheric carbon; conservation andrestoration of forests and their biological diversity;and, the assistance of host countries and communitiesin their socioeconomic development. However,prospective investors in CDM projects, host countriesand other CDM `stakeholders' might be expected toplace widely different priorities on achieving theseobjectives. This paper describes several factors thatwill affect investor interest in CDM projects, thecharacteristics of forest-based CDM projects that willattract investments, and an approach to identifyingprojects that meet the key objectives of multiplestakeholders. This approach entails identifyingsites, such as degraded watersheds, where CDMfinancing for forest conservation and restoration cangenerate readily monetizable local and regionalsocioeconomic benefits, while mitigating carbonemissions in forests with importance for conservingbiodiversity.     

开化县外向型创汇林业的战略模式

我国森林资源少,消耗量大,林业建设资金短缺。如何发展当前的林业生产、筹集林业建设资金,开化县的外向型创汇林业为我们走出了一条具有中国特色的外向型林业建设道路。本文就开化县发展外向型创汇林业的优点、出口创汇的主要对策、主要商品、发展潜力及其前景进行了论述,对目前正在探索适合我国国情的、解决我国林业“两危”的战略对策提供了现实的典型范例。     

Levels and Influencing Factors of Noise Pollution from Small-Scale Industries (SSIs) in a Developing Country

A study was carried out to determine levels and factors that influence noise pollution from small-scale industries (SSIs) in Dar es Salaam City Tanzania. Two sites for wood- and metalworks industries were investigated. Both sites exhibited equivalent noise levels higher than 90.0 dBA, the permissible exposure level limit for occupational noise. At a woodworks SSI, noise levels were found to correlate well with machine-use age, wood-feed speed, and wood-cut depth. Additionally, noise emanating from both types of SSIs was found to influence the level of environmental noise in the neighborhood of the SSIs. One woodworks SSI was found to have a circle of influence of about 140 m. The study concluded that SSIs present a serious source of environmental noise pollution in their neighborhoods. Noise pollution from SSIs is greatly influenced by the type of SSIs and the activities they carry out, the type and age of machines they use, their location relative to residential areas in their vicinity, and in-house noise control measures.     

Encouraging the application of sustainable timber harvesting practices: A review of policy tool use and effectiveness in the eastern United States

States use a variety of approaches to encourage landowners and loggers to apply ecologically-sustainable timber harvesting practices, the latter generically referred to as timber harvesting guidelines. A survey of 37 state forestry agency administrators in the eastern U.S. (defined as a contiguous region with the northwest and southwest borders being North Dakota and Texas, respectively) was conducted in 2000 to assess the extent and nature of state guideline programs and the various methods by which states encourage their use. The study found states in the eastern U.S. use a variety of policy tools to promote guideline use, with certain policy tools more common for certain target audiences (e.g., loggers) as well as the types of resources (e.g., wildlife habitat) addressed by the guidelines. Eighty-three percent of the programs directed at encouraging forest landowners in the eastern U.S. to use the timber harvesting practices identified in their state guidebooks are technical assistance, educational, or cost-share programs. Technical assistance and education programs are the most common policy tools used to assist loggers in applying sustainable harvesting practices. Technical assistance and cost-share programs consistently rank among the most effective policy tools for encouraging loggers and landowners to apply the guidelines. Comparing the level of program investment to perceived benefits, assistance programs and education programs rank most efficient landowner programs, whereas premium prices for products and preferential access to contracts are the two most efficient programs directed at loggers. The paper concludes with an assessment of emerging trends and additional information needs associated with encouraging the application of sustainable timber harvesting practices.     

Innovative approaches to rural development: Moving from state-controlled towards market-based land reform

Among the world's poor, approximately 75% of those in extreme poverty live and work in rural areas and two‐thirds of them depend mainly on farming or farm labour for their livelihood. Policies to grant the rural poor secure access to land and water for irrigation — and to improve the economic efficiency of small‐scale agriculture — can thus play a critical role in the implementation of rural development strategies, including efforts to combat rural poverty. Since inadequate access to arable land is probably the most important cause of rural poverty, redistributive land reform is increasingly seen as crucial for socio‐economic development and poverty alleviation in many developing countries with substantial amounts of (unused) arable state land or (under‐utilized) large private landholdings. This article argues that market‐based land redistribution schemes, such as the one being implemented in South Africa, can be considered one of the most innovative approaches to land reform that have emerged over the last decade. These schemes thus provide a useful alternative to more conventional, state‐controlled land redistribution programmes. The article concludes, however, that when countries opt for market‐based approaches to land redistribution, the State still has an important role to play, without necessarily deciding which land parcels change hands.