中国重要工业用材树种分子遗传标记

中国重要工业用材树种分子遗传标记张绪纹,苏晓华（中国林科院林业所,北京１０００９１）１引言我国主要的针叶树种杉木、油松、落叶松、云南松、马尾松和重要的阔叶树种杨树、按树是重要用材树种,它们为我国林木生产提供了大量的胶合板材、纸浆材、建筑材以及包装材料...     

优良园林绿化树种--榄仁

从形态特征、生态特性、繁殖与培育，园林价值及园林用途等介绍榄仁。     

海南短周期工业用材树种造林对比试验研究

通过造林对比试验及调查表明，厚荚相思和尾叶桉的胸径、树高、材积生长量较其他树种的生长量都有极显著性差异，其每亩年蓄积量分别为2．3m^3与2．0m^3。而木麻黄的材性基本密度最大与抗风性最强。     

干旱寒冷地区园林绿化优良树种--杜松

杜松为柏科刺柏属小乔木（河北又称棒儿松,因其树形紧凑而得名）,是珍贵的针叶常绿树种,它树形优美紧凑,生长缓慢,寿命长,病虫少,抗逆性强。具有耐干旱、耐寒冷、易繁殖、易栽培、易管理的特性,是干旱寒冷地区理想的绿化观赏、绿化美化树种。可用于城乡绿化、高速公路绿化、机关大院绿化美化、物业小区绿化美化等。     

南亚热带主要工业用材树种种质资源库保存技术研究

林木种质资源库保存是异地保存的重要形式之一,以林木种质资源保存理论为指导,在建立南亚热带主要工业用材树种种质资源库的同时,对保存材料收集,取样与保存设计,保存林的营造与管护,观测与评价等一系列的建库技术进行了研究,并对保存林的生长,适应以及保存的有效性进行了分析评价;论述了保存库保存过程中保材料的适应,驯化与变异、区域性的保存库应效进行了分析评价;论述了保存库保存过程中中保存材料的适应,驯化与变异、区域性的保存库应侧重收集保存本气候区的种质资源等问题,总结提出了收集、保存,评价与利用相结合的保存库保的技术要点。     

论我国珍贵用材树种资源的培育

珍贵用材树种资源是我国重要的战略资源。文章探讨了珍贵用材树种的定义,及开展珍贵用材树种资源培育工作的意义和面临的问题,并提出了相应的政策措施和技术路线。加快珍贵树种的培育除采取集约经营、定向改培、适当加大初植密度、加强抚育管理等技术措施外,要考虑与现有的林业重点工程相结合,与林下种养殖业相结合,城市绿化相结合。     

杉木：广西优良用材树种

杉木是一种常绿乔木,主要分布在我国亚热带地区。它与马尾松并列为广西两大速生优质用材造林树种,在广西分布范围很广。杉木是上等的建筑材、造船材、工业板材和各种家饰装修材等,历来为人们所喜爱。近10年来,已研究出杉木可用作造纸材和复合木地板材,同时杉木皮、叶、枝还可提取杉萜烯类物质用作医药使用。     

优良用材树种红胶木的栽培技术

1 形态特征，红胶木(Tristania Conferta R．Br．)属桃金娘科(Myrtaceae)常绿乔木，高可达40多m，胸径达180cm。其树干通直，材质坚重，木材抗白蚁，耐水下使用。木材宜作机械垫座、家具、农具、枕木、造船、造纸等。红胶木原产澳大利亚及印度尼西亚，我国引种已有近百年的历史，我省现有栽培。红胶木为阳性树种，喜生于深厚疏松肥沃的土壤，能耐0℃左右的极端低温，忌霜冻。树冠宽大，绿荫效果很好。花期5月，果实成熟期11月至翌年1月。蒴果成熟时由青色转为灰褐色，种子一般可留在果内1个月左右不散落。成熟的果实在树上可留半年左右，以后逐渐脱落。每果有种子400～600粒。种子纤细，线状，黄褐色，长2．0～3．8mm，径约0．3mm。     

马尾松：广西优良用材树种

松树、杉树、桉树、竹子是我国南方四大最主要的乡土造林树种和丁业原料树种。其中,马尾松是我国分布范围最广、面积最大的主要用材树种,广泛分布于我国南方16省市区,在森林资源发展和生态建设中占有十分重要的地位。广西林科院作为我国南方从事松树研究最主要的科研机构之一,建成了全国最大的松树种质基因库,     

优良速生用材和园林观赏树种——蓝云杉

蓝云杉（Piceapungens Engelm）,原产北美落基山中部的犹他州和科罗拉多州,在亚利桑那州和新墨西哥州也有分布,纬度跨越34°～45°。     

编制“森林工程木材物流规划设计符号”的应用意义

主要是对“森林工程木材物流规划设计符号”通过了全国森林工程标准化技术委员会审定以及需要不断充实和完善的论述.阐述木材物流规划设计中的术语和定义,包括工艺流程和工艺布局以及木流、涡流;符号包括工艺流程符号和工艺布局符号以及绘制要求和形象简化、易于识别和设施设备不限制方位及数量等.还包括编制这一标准的意义、应用范围、涵盖的内容以及作为行业标准需要不断充实和完善的充要条件.     

珍稀速生树种翅荚木栽培技术研究

对湖南翅荚木人工林进行了生长测定。结果表明：翅荚木在湖南丘陵红壤土年均胸径生长量可达2．0cm以上，年均树高生长量可达1．5m以上，蓄积年生长量为16．1m^3／hm^2以上。对翅荚木材性进行了分析与比较，木材密度为0．314g／cm^3，5a生翅荚木纤维长度1010μm，纤维宽度19．6μm，纤维长宽比为52。其木材材性与杨树、桉树相比十分接近。因此，翅荚木是一优质纸浆原料。由于其生长快，又可作为胶合板、家具用材定向培育。提出了相应的苗木培育与造林技术，并建议今后加强翅荚木优树选择、子代测定、良种基地建设等遗传改良的力度，加强其栽培技术研究，为我省营造翅荚木人工林提供技术支撑。     

Testing the durability of timber above ground: A review on methodology

The majority of timber products in outdoor use are exposed above ground, e.g. façades, terrace decking, playground equipment, garden furniture, windows, balconies or carports. In contrast, the durability of wood and wood products is most often determined in laboratory against Basidiomycete monocultures or in-ground field tests, where wood samples are submitted to permanent wetting. Worldwide, only a few above ground field test methods evaluating durability against fungal decay have been standardized. Wood used in above ground situations can be exposed to a wide range of moisture loads reflecting different design details such as varying shelter, distance to ground, ventilation and water trapping, whereas temperature and rainfall variations are overall influences on service life performance. The aim of this review was to gather information about standardized and non-standardized above ground field test methods used to determine the durability of wood and wood-based products. In total, more than 60 methods have been evaluated according to different criteria, such as principle set-up and design, severity of exposure and distance to ground. Their suitability to reflect a certain exposure under real-life conditions is discussed as well as practical aspects regarding acceleration measures, decay assessment and practicability, costs and time efforts.     

Structural health assessment of in situ timber: An interface between service life planning and timber engineering

Abstract

The 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.     

Crack influence on load-bearing capacity of glued laminated timber using extended finite element modelling

Abstract

Most of the cracks are caused by changes in temperature and relative humidity which lead to shrinkage and swelling of the wood and thereby induce stresses in the structure. How these cracks influence the strength of the wooden structure, especially the shear strength, is not well understood. However, it is reasonable to expect that cracks have an impact on the shear strength as they preferably run along the beams in the direction of grain and bond lines. The purpose of this study was to investigate the load-bearing capacity of cracked glulam beams and to find a model that could predict the failure load of the beams due to the cracks. Three-point bending tests were used on glulam beams of different sizes with pre-manufactured cracks. An orthotropic elastic model and extended finite element method was used to model the behaviour of the cracked beams and to estimate the load-bearing capacity. The conclusions were validated by numerical simulations of the mechanical behaviour of three-point bending of glulam beams with different crack locations. The crack initiation load was recorded as the failure load and compared to the experimental failure load. The results of the compaction simulations agree well with the experimental results.     

Varying moisture content and eigen-stresses in timber elements

Abstract

The load-bearing capacity of timber elements and systems is affected by moisture exposure. Varying moisture content in the ambient air and resulting non-uniform moisture profiles on cross-sections generate stresses perpendicular to grain because of restraint of hygroexpansion. This paper presents effects of indoor moisture diffusion in timber elements; moisture profiles within member and corresponding stresses are determined using finite element analysis and a relevant constitutive model. The stress variability is larger near the surface compared with the middle of a cross-section. No major differences are noticed between different climatic locations, but the induced stresses reach high levels above the characteristic strength in tension perpendicular to grain. It appears that indoor moisture effects differ insignificantly between the different climatic locations investigated in this study.     

湖南牡丹栽培历史和本土牡丹园建设

湖南牡丹药用有2 000多年历史,观赏栽培有1 000多年历史。明清时期形成湘西北以观赏牡丹为主和湘西南以药用牡丹为主的两个栽培中心。永顺县保存下来一批十分珍贵的古牡丹。2007年长沙王陵公园建立了湖南首个本土牡丹园,收集品种20多个,为湖南牡丹种质资源的科学保护及开发利用创造了条件。       

加强保护与培育珍贵树种资源的建议

由于经济社会发展的大量需求而进行的过度开发利用,导致珍贵树种资源的数量和质量持续下降,造成后备资源匮乏。因此,保护好现有的珍贵树种资源,积极培育和发展珍贵树种,增加森林资源总量和质量,对现代经济社会的发展具有重要意义。     

彩叶树种在园林绿化中的应用

彩叶树种在园林规划中有重要应用价值,本文阐述了彩叶树种的种类、着色原因,影响因素及在园林中的配置,旨在为彩叶树种的推广应用提供依据。