中国与俄罗斯、美国、日本原木检验标准比较研究

木材检验是木材贸易过程中的重要环节,木材检验标准或法规是评价木材材积和质量的重要依据。因采用不同木材检验的检测方法,各国在国际贸易中木材检验结果存在差异。文中对中国《原木检验》、俄罗斯《原木打号印、分类、运输、检量和验收方法》、美国《原木检尺和评等规则》和日本《原木等级和检尺规程》原木检验标准或法规进行比较,分析国内标准与国外标准在尺寸检验、材积计算和材质等级评定等方面的差异,以及不同检验方法间的相关性,以期为中国在进口原木贸易过程中标准制修订提供参考。     

国标与ATIBT标准的非洲紫檀原木材积测量值对比

通过对比非洲紫檀原木的ATIBT标准检量方法和国标检量方法，分析了导致2种检量方法差异的原因，找出2种标准测量材积的差异率随原木直径的增大而减少这一规律，并选用指数曲线做两者的回归分析，为企业经营决策提供参考依据。     

马尾松生长和收获模型的研究

利用马尾松人工林标准地材料，选择林分年龄、地位指数和断面积为辅助变量，采用逐步回归技术建立林分材积收获模型。从生长和收获的一致性出发，由材积收获方程对年龄取微分导出材积生长模型，并建立断面积生长模型。从而为预估森林生长量和收获量提供科学依据。     

顶果树人工林优树选择

以种植于广西南宁、柳州等地的顶果树人工林作为选优林分,采用5株优势木对比法进行选优,测量并分析44株候选优树和220株优势木生长量数据,应用差异显著临界值法确定优树选择标准。结果表明:优树选择标准为:树高≥优势木平均树高1.10倍、胸径≥优势木平均胸径1.09倍、单株材积≥优势木平均单株材积1.37倍。按此标准入选的优树有12株,入选率为27.3%,所选出的顶果树优树可为良种繁育提供基础材料。     

武功山林场火炬松优树选择技术研究

以火炬松树高、胸径和材积为数量评价指标，结合冠形、侧枝角和侧枝粗度等形质指标，采用5株优势木对比法对火炬松人工林分开展优树选择研究，并根据分析结果制定了不同栽培密度下优树选择标准，符合该选优标准的候选优树有23株入选，总的入选率为48.94%。本研究制定的优树选择标准可为相似栽培密度的火炬松林分中优树选择提供了参考，选出的优树资源为火炬松种子园建设和育种群体的构建提供了优质材料。     

辽东山区日本落叶松用材林优树选择标准的商榷

通过对辽宁东部山区日本落叶松用材林的调查，初选优树２５株，优势木７５株。经过ｔ经验，初步确定日本落叶松用材林优树选择的最低标准为：树高超过优势木平均树高的８％，胸径超过优势木平均胸径的１４％，材积超过优势木平均材积的４６％，该标准适用于辽宁省东部山区日本落叶松用材林的优树选择。     

白蜡优树选择方法与标准的研究

通过对白蜡人工林生长状况的调查,探明了同龄白蜡雄株生长量明显大于雌株生长量。采用雄株和雄株对比的选优方法对候选优树和优势木生长量数据进行分析,确定了雄树选优标准为：树高≥优势木平均树高1.1倍,胸径≥优势木平均胸径1.1倍,单株材积≥优势木平均单株材积1.5倍;雌树选优标准为：树高≥优势木平均树高1.15倍,胸径≥优势木平均胸径1.14倍,单株材积≥优势木平均单株材积1.6倍。     

杉木的受害允许水平及粗鞘双条杉天牛防治策略研究

本文在９年生人工纯林中，采用固定标准地、固定标准株连续３年对树高、胸径实测的方法，计算并比较阌 害与末受害木材积及单位面积材积的 失。     

不同计算方法杉立木材积差异及其相互关系分析

通过对兰溪市采伐杉立木2m区分段材积（作为立木真实材积）、实验形数材积、根径一元材积、胸径一元材积、原条折算材积、木材重量折算材积的比较分析，得到实验形数材积与2m区分材积之间无显著差异，在实际应用中可作为立木真实材积；其它计算方法材积与2m区分材积之间差异显著，但存在显著回归关系；原条出材率明显大于省定综合出材率，应根据情况加以材积转换。     

赤桉优良家系选择分析

以8年生赤桉种源试验林的141个家系为材料,进行3个生长性状遗传变异分析,并根据各家系单株材积表现进行优良家系选择,结果表明：树高、胸径、材积3个性状在家系水平存在极显著的差异;家系遗传力与单株遗传力具有同样的规律：胸径遗传力〉树高遗传力〉单株材积遗传力。由遗传相关系数来看,以家系单株材积表现进行赤桉优树选择比其他性状更具指导意义。以表现水平法和T检验,2个不同参照标准,选择出103、106、108号等13个优良家系,其中前3名家系单株平均材积分别达0.1120m3、0.0944m3和0.0936m3。     

近年木材进出口贸易概况及对木材产业相关问题的思考

通过分析2005年我国木材贸易进出口情况与2006年的走势,从资源利用的角度,探讨我国木材产业的发展前景,指出我国木材产业应逐步由劳动密集型向资金密集型和技术密集型转化,开发新技术和新产品,以质量、品牌和信誉打开国际市场,对国际上一些意在恶化中国进口木材国际环境的论调进行了反驳.     

Using a Small-Log Mobile Sawmill System to Contain Fuel Reduction Treatment Cost on Small Parcels

The Authors tested a mobile small-log sawmill system that could produce cants and boards of variable size, according to the needs and specifications of each property owner. The unit was deployed as part of a comprehensive mechanical fuel reduction operation, aimed at thinning small properties around homesteads. Working on conifer small logs, the mill proved very efficient, with a processing productivity between 0.3 and 2.8 m³ of lumber per working hour and a recovery rate of 50% for boards, and 67% for cants. The mill could be set up and dismantled in a few hours and was easy to move around. However, the exceedingly small amount of logs available at each site entailed a low utilization of the mill (about 25% of the time) and a consequently high processing cost. Under the conditions of the study, milling cost can be contained below 150 US dollars per m³ of lumber only if the single site offers at least 50 m³ of logs, already sorted during harvesting. Hence the suggestion of pooling the wood obtained from small parcel fuel reduction treatments in satellite yards and milling it only when a large enough amount has been accumulated. In turn, satellite yards could be organized into an integrated network complementary—rather than alternative—to stationary mills.     

2008年上半年我国进口木材市场分析

今年上半年我国进口原木数量开始以较大幅度下降,进口锯材数量增幅也变缓。原木和锯材是我国林产品进口中的大宗商品,近年来均以较高的增速连年增长,而今年上半年进口额大幅度下降的趋势,必将对我国的木材进口企业和木材加工企业产生较大的影响,应引起我国木材行业的高度重视。     

Towards defining a wood quality index for the eucalypts: the R-ratio

Summary The derivation of a value termed the R-ratio (the change in external wood volume during shrinkage or swelling per change in the weight of the associated volume of water) and its possible use as an indicator of dimensional stability (Chafe 1986, 1987), has led to its consideration as a potential wood quality index for the eucalypts. An analysis of R with respect to mechanical strength, durability, volumetric shrinkage, collapse and density in 38 species of eucalypts has shown a high degree of correlation and suggests that R could provide a single overall indication of timber quality.While density was more highly correlated with strength and durability than R, the R-ratio was more highly correlated with shrinkage. Also, when predictor criteria (strength, durability, shrinkage, density) were mutually adjusted in multiple regression analysis, R remained significantly correlated with each. When density was similarly regressed against shrinkage, durability and strength, the relationship was not significant for shrinkage.The observed high correlation between durability and density suggests that mass of wood substance is an important criterion in defining resistance to wood decay.The author wishes to thank Dr. W. E. Hillis, Mr. W. G. Keating, Mr. J. Ilic and Mr. E. P. Lhuede for kindly assigning wood quality rankings to the 38 species of Eucalyptus discussed herein     

Stress wave sorting of red maple logs for structural quality

Existing log grading procedures in the United States make only visual assessments of log quality. These procedures do not incorporate estimates of the modulus of elasticity (MOE) of logs. It is questionable whether the visual grading procedures currently used for logs adequately assess the potential quality of structural products manufactured from them, especially those for which MOE is of primary concern. The purpose of this study was to investigate the use of stress wave nondestructive evaluation techniques to sort red maple logs for the potential quality of lumber obtained from them. Ninety-five red maple logs were nondestructively evaluated using longitudinal stress wave techniques and sorted into four stress wave grades. The logs were then sawn into cants and lumber. The same procedure was used to obtain stress wave times in the cants and lumber. The lumber specimens were then dried and graded using a transverse vibration technique. The results of this study showed that good relationships existed between stress wave times measured in logs, cants, and the lumber produced from the logs. It was found that log stress wave grades have positive relationships with the lumber grades. Logs with high stress wave grades produced high-grade lumber. These findings indicate that the longitudinal stress wave technique has potential in sorting logs and cants for the production of high MOE products.The Forest Products Laboratory is maintained in cooperation with the University of Wisconsin. This article was written and prepared by U.S. Government employees on official time, and it is therefore in the public domain and not subject to copyright.     

A. Study of Compression Wood in Scots Pine (Pinus silvestris L.): With I Plate

The incidence of compression wood was studied in 24–40-year-oldScots pine plantations. It was found that compression wood distributionin trees depended on type of stem curvature and was associatedwith their attempts to correct stem inclination. Compressionwood volume percentage was not closely related to extent ofstem curvature but was highly correlated with compression woodpercentage in the tree at breast height or 10 feet. There wassignificantly less compression wood near the butt than at higherlevels. In stands examined, compression wood formed 20–40per cent, of the standing volume. The prevailing wind appearedlargely responsible for the initial development of stem inclinationand consequent compression wood formation. Provision of shelterduring establishment should reduce compression wood developmentin second rotation crops.     

世界制材工业现状及发展趋势

本文概述了世界制材工业现状，从林木资源利用、提高锯材质量、完善加工工艺、开展小径木加工，采用高新技术等方面，介绍和论述了世界制材工业的发展趋势。针对我国制材工业的现状和存在的问题提出了解决对策。     

我国木材工业发展方向

在总结世界先进国家木材工业发展动态和科技开发发展方向的基础上,提出在全球经济一体化新形势下,我国木材工业应根据国家可持续发展战略的总体目标,加强科研开发和自主创新,吸取先进国家的有益经验,推进经济结构调整和经济增长方式转变,走科学的新型工业化发展道路.     

中国木材工业数控化的普及

分析我国木材加工机械制造业及其数控化的现状，提出发展分工明确的产业集团，研究进入木工机械数控化的突破点，引进国外数控木材加工机械的先进技术，依靠产学研合作攻关，开发有中国特色的数控机械产品，将是我国木材加工机械数控化发展的方向和模式。     

木材加工工业科技发展战略探索

作者以系统论的观点,从理论上详细阐述了我国木材加工工业科技工作与生产部门之间现时存在的主要问题及其实质。根据系统整体优化的观点,从木材加工科学技术的4个方面:产品结构调整和改变,产品设计工程,新技术应用和软科学的研究与应用,提出了今后木材加工工业科技工作的战略目标和为实现这一目标应确立的主攻方向。