国外桉树人工林资源和木材加工利用现状

从桉树人工林的资源现状、桉树人工林的木材性质、加工利用技术以及桉树木材产品的市场发展4个方面,概述了国外桉树人工林的发展及其木材利用状况.着重介绍了影响桉树人工林低龄材利用的木材性质以及锯解和干燥技术.通过学习和借鉴国外桉树木材加工利用的先进技术和经验,以提高我国桉树木材的利用水平.     

澳大利亚桉树木材加工利用研究现状*

分析了澳大利亚桉树资源、桉树木材性质、干燥特性、实木加工及其产品开发与利用等方面的研究内容与结论．以期为我国充分合理使用桉树人工林木材以提高桉树木材自身的使用价值提供一些借鉴。     

桉树人工林沃土保育与可持续经营思考

桉树是南方国家储备林的重要树种,广西是全国的木材生产大省,占全国木材生产总量的1/3,其中桉树面积约200万hm2,占全区人工林面积的25%左右,提供全区约80%的木材,有力支撑了全国的木材供给。然而由于人为的不科学合理的经营模式,引起的桉树林地生物多样性减少、林地土壤肥力下降等生态问题比较突出,制约桉树人工林可持续经营。针对这些问题,结合广西桉树生产实际和桉树科研成果,本文提出了实施桉树人工林沃土保育工程,实现桉树林地可持续经营的决策建议。     

桉树大径材和无节材培育技术探究

指出了桉树是我国纸浆材的主要树种,培育出大径材的桉树可以有效地缓解我国对木材的需求,尤其是缓解我国中径木材、大径木材紧缺的失常状况,从而解决我国木材市场上供需不平衡的矛盾。阐述了桉树大径材培育的重要意义,进一步提出了桉树大径材和无节材培育技术的有效策略,以为我国实现桉树种植效益最大化起到参考作用。     

桉树人工林经营存在问题与丰产造林技术探讨

桉树是桃金娘科Myrtaceae桉树属Eucalyptus的总称,共有945个种和变种.桉树速生、耐瘠薄、干形好,木材和非木材产品有极高的经济价值.     

巴西桉树人工林资源及其实木加工利用

桉树作为一种重要的速生人工林木材资源，具有大规模生产高附加值实木制品和木质复合材料的巨大潜力。巴西桉树人工林的营林技术、林业管理和实木利用水平位居世界前列。文中在对巴西桉树人工林资源、管理和木材加工利用等多个领域进行考察的基础上，阐述了巴西在桉树人工林营林、管理、木材加工技术等方面的成功经验，以及桉树产品市场的发展背景、现状和趋势。     

我国桉树人工林资源和木材利用现状

本文概述了我国桉树人工林资源状况,分析了桉树人工林木材性质的研究及加工利用现状，指出桉树人工林木材利用的巨大潜力，并对我国桉树人工林的可持续发展提出建议。     

桉树木屑袋栽香菇试验初报

桉树是世界著名速生树种,我国引种桉树已有百余年历史,福建省永安市自1991年引种桉树以来,现推广面积达0.2万多hm~2。桉树木材是优良的造纸和人造板工业用材,其木材富含芳香油,尚未见有栽培食用菌的报道。本试验采用桉树木栽培香菇食用菌,试验结果表明,桉树木材通过常规处理即可袋栽香菇,是一种很有发展前景的食用菌原料林造林树种。     

我国桉树人工林材性和加工利用研究现状与发展趋势

概述了桉树人工林发展概况,全面分析了桉树人工林木材性质与加工利用研究现状和存在的问题,指出应该真正将按树人工林育种、栽培措施、木材性质与加工利用结合起来进行研究,实现桉树人工林的定向培育、合理、高效利用。     

我国桉树木材性质及其变异规律研究进展

概述了国内桉树木材解剖性质、物理力学性质、化学性质及其变异规律的研究现状,对桉树木材性质变异的影响因子及其材性遗传相关性研究进行了总结,最后分析其存在的问题,并展望了桉树材性遗传改良的研究前景。     

桉木美学家具设计与工艺研究

为探索美学家具设计和桉木高值利用的可行途径,本文综合运用仿生学、设计学、木材美学和木材加工工艺学等多学科知识,从作品设计、制作工艺和作品分析三个方面系统讨论了两款以桉木为原料的美学家具.结果表明:通过合适的模具设计,采用单板层积材的生产工艺,可以用桉木单板生产出多拐点的复杂曲面板材.将这种多拐点的复杂曲面板材应用于家具设计与生产,可以获得兼具实用和审美功效的桉木美学家具.通过桉木美学家具的研发和生产,可望实现桉木资源的高值利用.     

桉树人工林木材加工过程中几个问题的探讨

就桉树人工林木材在加工过程中出现的:采伐时产生端部开裂、制材加工困难、易产生劈裂、干燥时容易发生皱缩和开裂、机械加工困难、胶合和涂饰困难等5个生产问题进行了理论分析,探讨了出现这些问题的原因,提出解决这些问题的具体措施.     

Method of check analysis of microwave-modified wood

A photo-based method for statistical image analysis of microwave (MW)-modified timber was developed and applied to test sets of Radiata pine and eucalypt hardwoods (Messmate and Mountain Ash). The method is based on filling the checks in timber with stain solution and analysing the wood surface. Bethel impregnation process (in a pressurised treatment vessel) was used to produce uniform surface staining of the test samples. Image processing was automated and the number of manual operations (the human decision-making process) was minimised. A computer program that automates thresholding and a program that repairs the threshold image were written. The software allowed larger images to be analysed and reduced image processing time. The described method produced reliable check measurements and statistics for softwoods. Though suitable for estimating the quality of individual MW-modified hardwood specimens, the method was found to be inadequate for statistical analysis of eucalypt hardwoods because of collateral staining of vessels accompanied with a high level of stain penetration into the wood tissues.     

Influence of steam heating on the properties of pine (<Emphasis Type="Italic">Pinus pinaster</Emphasis>) and eucalypt (<Emphasis Type="Italic">Eucalyptus globulus</Emphasis>) wood

Heat treatment of Pinus pinaster and Eucalyptus globulus woods, two important species in Portugal, was performed in the absence of air by steaming, inside an autoclave, for 2–12 h at 190–210°C. Mass losses increased with treatment time and temperature reaching 7.3% for pine and 14.5% for eucalypt wood. The wood behaviour with moisture was improved. The equilibrium moisture content decreased by 46% for pine and 61% for eucalypt, the dimensional stability increased (maximum anti-shrinking efficiency in the radial direction of 57 and 90% for pine and eucalypt, respectively) and the surface wettability was lowered. In relation to mechanical properties, the modulus of elasticity was little affected (maximum decrease of 5% for pine and 15% for eucalypt) but the bending strength was reduced (by 40% at 8% mass loss for pine and 50% at 9% mass loss for eucalypt wood). The variation of properties was related to treatment intensity and mass loss but significant improvements could already be obtained for a 3–4% mass loss without impairing the mechanical resistance. The response of eucalypt was higher than that of pinewood. Heat treatment of eucalypt wood shows an interesting potential to improve the wood quality for solid timber products.     

五种桉树木材的吸声性能

本文以广西东门林场的人工林尾叶桉(Eucalyptusurophylla),尾巨桉(EucalyptusurophyllaE.grandis),尾园桉(E.urophyllaE.tereticornis),尾赤桉(E.urophyllaE.camaldulensis)和大花序桉(E.cloeziana)木材为主要材料,用驻波管法测试了五种桉树木材的吸声系数,比较了这些桉树木材的吸声性能,结果显示五种桉树木材的吸声系数在频率1000赫兹之内变化不大,之后随频率的增加吸声系数也在增加。在频率200至2000赫兹范围内,五种桉树木材的吸声系数差异不显著,在低频区域,尾叶桉的吸声性能较好。在所测试的声波频率范围内,桉木弦锯板的吸声系数高于径锯板;0.5厘米厚的锯材的吸声性能好于1.0厘米厚的锯材;因此,桉木板材的种类和板材的厚度影响其吸声性能,但五种桉树木材的吸声性能差异不显著。图2表4参6。     

Sound absorption property of wood for five eucalypt species

The sound absorption coefficients of wood and wood boards for five eucalypt species (Eucalyptus urophylla, Eucalyptus urophylla x E. grandis, Eucalyptus urophylla x E. tereticornis, Eucalyptus urophylla x E. camaldulensis and Eucalyptus cloeziana) that were collected from plantation in Dongmen Forestry Center of Guangxi Province, China were tested with standing wave method and their sound absorption properties were also compared. The results showed that the sound absorption coefficients of the five eucalypt wood species did not change evidently below 1000 Hz, but above 1000 Hz their sound absorption coefficients increased with the increasing frequency. The difference in sound absorption coefficient among five species of eucalypt wood is not evident at the tested frequency range (200–2000 Hz), but the sound absorption property ofEucalyptus urophylla at low frequency is better than that of other four species. The sound absorption coefficient of the tangential-sawn board is higher than that of the radial-sawn board. The sound absorption property of eucalypt wood of 0.5 cm in thickness is much better than that of 1.0 cm in thickness. It is concluded that wood sound absorption properties of eucalypts are affected by their board thickness and the type of sawn timber within the testing frequency, but the variance of wood sound absorption property among the five tested species is not significant. Fundation item This study is Part of 2000-4-13 in “948” Project from the State Forestry Administration of P.R. China Biography: JIANG Ze-hui (1939-), female, Professor in Research Institute of Wood Industry in Chinese Academy of Forestry. Responsible editor: Chai Ruihai     

科学地认识我国南方发展桉树速生丰产林问题

针对目前中国南方出现的“发展桉树有害论”, 说明了这些流行观点多属于想象、误解和超出真实的夸张; 在论证了桉树的经济优势的基础上, 着重从水文效应、地力效应、生物效应等方面证明桉树非但不是生态杀手, 且有一定的生态服务功能; 在分析了国家木材安全形势和介绍了国外的发展经验的基础上, 着力阐述了发展桉树速生林在解开国家林业领域的环境经济矛盾中的关键作用。文中否定了桉树有害论, 但同时也指出某些企业发展桉树人工林时缺乏社会责任心以及缺乏与农民的沟通。     

Eucalypt Wood Anatomical and Physical Properties and Their Effects on Plywood Veneer Quality

In order to better understand the reasons why eucalypt veneer checks easily and severely, wood samples of three eucalypt species were selected, and their anatomical and physical properties were examined according to conventional methods and the national standards. The effects of variances in cell wall thickness of wood fibre and vessel, and diameter of the cell lumen as well as the tissue ratio on the quality of plywood veneer were analysed. The results show that： 1） There is a great difference in fibre cell wall thickness and diameter of the cell lumen between early wood and late wood of Eucalyptus delegatensis. 2） E. obliqua has a high wood fibre tissue ratio and the thickest fibre cell wall, but the difference inthe fibre cell wall thickness between early wood and late wood is the smallest. 3） The wood fibre tissue ratio of E. regnans is smaller than that of E. obliqua, and its wood fibre cell wall isthe thinnest and there is only a very small difference in fibre cell wall thickness between early wood and late wood. The difference inthe diameter of wood fibre cell lumen among early wood, transition area and late wood is also small： 4） E. delegatensis has the highest tangential shrinkage rate and radial-tangential shrinkage rate, andE. obliqua has the lowest. It is the variability of wood anatomical properties of these species that cause the difference in the veneer shrinkagei and then affects plywood veneer quality.