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1.
The Government of Indonesia (GoI) and the European Union (EU) have signed a Voluntary Partnership Agreement on Forest Law Enforcement Governance and Trade (FLEGT-VPA), which aims to prevent illegal timber products from entering the EU. This agreement recognizes a certification for timber products exported from Indonesia based on FLEGT-VPA standards and implemented through the timber legality verification system, Sistem Verifikasi Legalitas Kayu (SVLK). While the implementation of SVLK complies with the FLEGT-VPA, it has not dissolved pre-existing national systems for forest management and timber trade. Implementing SVLK standards amid multiple forest regimes causes redundancy of administrative procedures in forest management and timber trade in Indonesia. This redundancy, in turn, leads to decrease in cost efficiency, weak legitimation, and low effectiveness of the system, especially in community forests. 相似文献
2.
文章介绍了木材检验技术在木材运输中的作用与地位,分析了木材运输中常见的木材检验技术误区,阐述了由此引起的责任风险或者造成的危害,并依据现行木材检验标准规定,针对性地提出了规范的木材检验技术操作要领。 相似文献
3.
This paper reports findings of surveys into small-scale sawmilling and timber processing in Phu Tho Province and the Tam Dao
National Park buffer zone in northern Vietnam. The objective of these surveys was to examine the extent to which small sawmills
and timber processors utilise farm-grown timber, so as to explore the prospects for expansion of farm-grown timber markets.
The operational scope, supply chain and value chain of the industry are reported. Resource availability and current and future
perspectives are discussed. Timber prices were found to vary greatly between species and study areas. Species most in demand
by enterprises are Artocarpus heterophyllus, Melia azedarach, Manglietia conifera, Acacia spp., Chukrasia tabularis and Erythrophloeum fordii. Small-scale sawmilling and timber processing activities fit well with rural communities in Vietnam and have potential for
further development if current constraints can be overcome. Further tree planting is needed to meet the presently unsatisfied
timber demand and to create income and employment. Information from sawmillers and timber processors suggests the types of
species that farmers should be considering for their plantings. 相似文献
4.
我国红松大径级用材林近自然培育探讨 总被引：1，自引：0，他引：1
红松是地带性森林植被阔叶红松林的建群种,其木材力学强度适中,纹理通直,花纹美观,材质强韧,不易开裂、变形,耐腐朽力强,为我国珍贵用材树种。通过近自然经营可以达到低成本培育大径材近自然林的目的。文中分析了我国红松大径材林培育现状及存在问题,并从红松的生物和生态学特性、木材利用价值方面阐述了大径级用材林近自然培育的适用性,提出了红松大径级用材林近自然培育技术,包括原则、目标树选择时间、大径材目标树选择技术、目标树密度、干扰树确定方法、种源与立地条件的确定等,以期为提升优质大径材蓄积量和满足国家需求提供一条有效途径。 相似文献
5.
《Wood material science & engineering》2013,8(2):81-87
ABSTRACTIn forestry, thinning operations result in the extraction of young trees with small dimensions. The evaluation of the potential end use of these small-diameter logs (currently mainly used as poles or fence posts) for added-value products such as structural timber is of considerable economic and industrial interests. In the present work, 216 pieces of small-diameter logs of chestnut timber obtained from thinning operations were evaluated in order to determine their mechanical properties and assess various visual or non-destructive grading systems. The two visual standards evaluated (EN 1927 and DIN 4074) were ineffective in grading according to mechanical properties. On the other hand, a grading system based on a non-destructive measurement (acoustic wave velocity) resulted in better classification by structural quality. The characteristic values of the small-diameter round chestnut timber, determined according to the standards EN 384 and EN 338, achieved similar values as standard rectangular sawn timber with respect to modulus of elasticity and density, and higher values for bending strength. 相似文献
6.
非结构集成材的加工及应用已非常普遍，但目前国内还没有加工及检验标准，各企业采用的标准不统一，致使检验结果不具有可比性。论述了非结构集成材的生产工艺及检验标准，简要介绍了即将颁布的非结构集成材行业标准。 相似文献
7.
Bohumil Kasal 《Wood material science & engineering》2014,9(3):134-138
AbstractThe in situ assessment of timber structures has gained considerable attention in recent years due to some unexpected failures of public buildings. The assessment of timber, however, has been used in the evaluation of historic structures for a number of years, and the methods employed have evolved from visual observation (which is still one of the most effective ways of evaluating in situ timber) to more sophisticated methods that use various physical phenomena such as stress-wave or X-ray energy attenuation. In the health assessment of timber, effects of biotic elements such as insects and fungi are of interest, which, of course, is always connected with the presence of water in wood. The structural assessment encompasses questions related to the structural integrity of in situ members and the performance of components and the system. The structural health assessment not only focuses on biotic elements but also attempts to quantify engineering properties of the material such as strength degradation, modulus of elasticity, loss of cross-section, extent of checks, and other quantitative parameters needed for subsequent evaluation of the structural system, frequently expressed as load-bearing capacity. Service life planning of a structure is a complex issue that is related not only to the materials but also the environment and the use of the structure. Assessment of the health and properties of existing timber elements yields a piece of information that is necessary but not sufficient for the service life estimate. In the evaluation of structural timber, a mere use of various assessment techniques is not sufficient and usually an involvement of disciplines such as wood anatomy, wood physics, and statistics is needed. A reliable estimate of the parameters of in situ timber requires careful planning of measurements (experiments) since the material is highly variable and any statement about the properties of an element or even the entire system must reflect the random character of the wood properties. This paper will summarize the state-of-the art methods used in the assessment of in situ timber and analyze the strengths and the weaknesses of selected methods. An attempt will be made to outline future directions in the development of in situ assessment methods. 相似文献
8.
基于表面主要缺陷的锯材外观质量量化评价方法 总被引：1，自引：0，他引：1
【目的】提出一种锯材外观质量量化评价方法,探索锯材外观质量数字化检测与评价分级的可行性,为实现锯材外观质量的实时在线检测提供基础理论和技术支撑。【方法】建立由密闭暗室、光源、工业相机等组成的锯材表面缺陷在线检测系统,在稳定光环境下采集样本锯材彩色图像。基于图像处理技术开发软件试验系统,实现对锯材缺陷的检测和识别。分别建立节疤、孔洞和裂缝缺陷外观质量评价模型,并据此提出外观质量综合量化评价方法;通过与国家标准对照,验证本研究提出方法的科学性和可行性。【结果】量化评价方法与锯材材质指标等级进行对照,二者线性相关系数为0.85;锯材材质指标等级除了2级和3级对应的综合量化评价值分布比较分散、等级之间数据有部分交叉外,其他等级之间对应的综合量化评价值分布几乎没有交叉。量化评价方法与集成材层板外观质量要求进行对照,二者线性相关系数为0.88;锯材材质指标等级4级对应的综合量化评价值分布比较集中,与其他等级之间没有数据交叉;锯材材质指标等级1级、2级和3级相邻等级对应的综合量化评价值分布比较分散,等级之间数据有部分交叉,不相邻等级间数据分布没有交叉。【结论】综合量化评价值与依据有关国家标准确定的锯材材质指标等级、集成材层板外观质量要求的线性相关性相对较好,可为实现锯材外观质量数字化检测与评价奠定基础;通过调整模型有关影响系数,可满足不同树种和不同应用需求,以达到较好评价效果。 相似文献
9.
通过对我国原木生产实际状况的调研及参考国内外相关标准和技术资料，阐述了木材缺陷对规格材力学性能的影响，并据此对轻型木结构锯材用原木缺陷的技术指标进行了规定，同时介绍了该标准的制定方法。 相似文献
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Small volumes of timber from Acacia and Eucalyptus woodlands of western Queensland, Australia, have achieved high prices in specialty timber markets, which has aroused the
interest of landholders. A postal survey of 225 domestic and international specialty timber product manufacturers was undertaken
to determine current utilisation of these lesser-known species, establish their suitability for various product markets, ascertain
desirable timber dimensions and condition, and estimate potential future domestic and international demand. An overall response
rate of 31% was achieved. Responses indicated that current utilisation of these timbers is probably not more than 200 m3/yr. Nevertheless, respondents generally indicated that western Queensland hardwoods are highly suited to the manufacture
of specialty timber products, including small-scale furniture items, custom knife handles and musical instruments, and that
they have high export potential. Some furniture and musical instrument manufacturers indicated they would be willing to pay
up to $3,000/m3 and $30,000/m3 respectively, for small volumes of high-quality appropriately processed western hardwoods. Large, well-directed marketing
campaigns will be necessary to expand specialty timber markets for western Queensland hardwoods. 相似文献
12.
本文通过对培育杨树工业用材林的立地条件,栽培品种选择,合理密度及最佳轮伐期的确定,以及栽植,林分抚育管理等关键技术措施的论述,为实现定向,速生,丰产,优质,稳定和高效的培育目标,建立了辽宁省的杨树工业用材林基地,提供了可靠的技术保障。 相似文献
13.
Matthew J. Kelty Luisa Cámara-Cabrales James Grogan 《Journal of Sustainable Forestry》2013,32(7):637-653
Complex mixed-species forests are the focus of conservation efforts that seek to maintain native biodiversity. However, much of this forestland is privately owned and is managed for timber income as well as for conservation. Management of these high-diversity forests is particularly difficult when only one tree species produces the majority of high-value timber. We examined the past and current management of two regions which have those characteristics: Massachusetts, USA, with red oak (Quercus rubra L.) as the key timber species, and Quintana Roo, México, with big-leaf mahogany (Swietenia macrophylla King) as the most valuable species. These regions have different ecological characteristics, forest ownership types, landowner income, and importance of timber in total income, yet the silvicultural approach (low-intensity selective cutting) is surprisingly similar, and is generally failing to provide the conditions needed for regeneration and growth of key species. In both situations, the reluctance to harvest low-value species and interest in minimizing forest disturbance complicates management. Successful balance of timber harvest and forest conservation may be an important factor in preventing conversion of these lands to agriculture or residential development, but socioeconomic conditions (property tax policies and landowner affluence) play an important part in the outcome. 相似文献
14.
A. Egger 《Journal of pest science》1974,47(1):7-11
Summary
A contribution to the morphology and biology of Hylecoetus dermestoides L.
At first the occurence ofHylecoetus dermestoides L. in the Austrian forests near Aflenz and Rosaliengebirge is described. Analyses of beech stumps are carried out. In general,
beech stumps and beech stems are covered with eggs not earlier than one year after felling. The mechanical devices for timber
processing such as chitin saws of the larvas and their function is throroughly described. It was found, that the chitin saws
are accomodated to the steadely changing timber resistance of the canal walls due to timber decomposition byAmbrosia-mushrooms which are cultivated by the larvas.
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A computer model was developed for the economic analysis of the damage caused to cocoa plants (Theobroma cacao) due to the harvest of timber shade trees (Cordia alliodora), based on field estimations from cocoa farms in the indigenous region of Talamanca, in the south east of Costa Rica. An
economic cost-benefit analysis was carried out considering cocoa planting densities, yields, timber volumes and both cocoa
and timber prices. Damage to cocoa plants was quantified in terms of severity levels and then translated into yield losses
and their corresponding economic values. From the 49 harvested timber trees observed, 196 cocoa plants were affected, of which
4% required replanting and 38% coppicing. Tree trunks were involved in 55% of the damage cases (109) and tree crowns in 45%
(89). Nevertheless, the revenue obtained from timber sales easily offset the costs of damage to the cocoa crop. The economic
analysis showed that on average, the net gain derived from timber harvesting was around US316 per tree. For all considered scenarios, the timber market price that would balance discounted costs and benefits to zero ranged between US316 per tree. For all considered
scenarios, the timber market price that would balance discounted costs and benefits to zero ranged between US22 and US$66 m−3 (current market price for C. alliodora is US$66 m−3 (current market price for C. alliodora is US128 m−3). There would be lower margins due to higher costs of cocoa damage in high yielding, high price cocoa scenarios. However,
the study shows that damage due to tree felling should not be a major objection of farmers to the use of timber shade trees
in cocoa farms even in these scenarios. 相似文献
18.
三明市材种出材率表编制是根据部、省有关材种规格标准，进行现场造材，共收集１１６４株样木，其中杉木５５６株，马尾松６０８株。采用电子计算机对样木进行计算和分析，以确定各树种树高级、径阶、材积、树皮率、出材量和出材率。 相似文献
19.
Kana Yamashita Yasuhiko Hirakawa Shuetsu Saito Hiroshi Nakatani Motoyoshi Ikeda 《Journal of Wood Science》2011,57(5):363-370
To evaluate the bow variation in boxed-heart square timber of sugi (Cryptomeria japonica), bows from kiln-dried timber for five sugi cultivars with different longitudinal shrinkage trends were compared for two
stem heights. Two general trends were observed, depending on the cultivar: (1) either the bow was larger at the lower than
at the upper part of the stem, or (2) the bows at the lower and the upper parts of the stem were similar. In timber that had
larger bow values, the gradients of longitudinal shrinkage were large across the radius and along the length of the timber.
There was a positive relationship between the bow and longitudinal shrinkage. These results suggest that the bow variation
between the timbers was caused by a variation in longitudinal shrinkage, which was affected by the microfibril angle. Furthermore,
the bow was inversely proportional to the modulus of elasticity, which suggests that timber with a low modulus of elasticity
is susceptible to a large bow due to large longitudinal shrinkage. 相似文献
20.
Valery Kozlov 《Wood material science & engineering》2014,9(3):156-161
AbstractService life of timber structures in the north of Europe is decreased mainly by biological agents. Increasing risk of biological infestation due to global warming is widely discussed nowadays. Historic timber structures which have been monitored for decades provide us with valuable information on this subject. An investigation of the structures in the Kizhi museum, located in the northwest of Russia was carried out in the 1970s and in 2011–2012. Identification of wood-decay fungi that destroy constructive elements of seventeenth- and nineteenth-century monuments showed that the most frequent damages are caused by brown rot fungi. At the same time, imperfect fungi and ascomycetes which cause soft rot began to play a significant role in damaging historic timber structures. Borers (Hadrobregmus pertinax L. and H. confusus Kraaz) play the leading part in reducing the service life of seventeenth- and nineteenth-century heritage objects. During a forest inventory, some wood-borers not registered previously as timber structure pests in the Kizhi archipelago region (Republic of Karelia, Russia) were found. Twenty-seven species of foliose and fruticose lichens and ten species of crustose lichens were found on the monuments' structural elements. 相似文献