中国林产品质量与标准化技术研讨会在杭州召开

<正>2014年6月,"中国林产品质量与标准化技术研讨会"在杭州召开,公益性行业"双打(打击制售假冒伪劣商品、打击侵犯知识产权)"专项的林业相关产品检验鉴定技术标准研讨会同期召开,旨在通过研讨,加强林产品质量和标准化研究,通过质量监控手段,促进我国林产品产业的转型升级。会议由全国人造板标准化技术委员会和木材标准化技术委员会主办,中国林科院木材工业研究所和浙     

热处理木材及其在欧洲的发展

有效的利用木材资源是一个令人们关注的重要课题,尤其是在森林覆盖率低的国家。由于环保意识的增强,人们对木材的功能性改良越来越多地侧重于采用物理处理方法。在这样的背景下,木材热处理在许多发达国家迅速的蓬勃发展起来,尤其是在欧洲。欧洲许多国家的科研机构和生产企业都进行了大量的研究,一些大的木材热处理厂也相继建立。本文回顾了木材热处理技术的发展历程,列举了热处理木材在以荷兰、德国、法国和芬兰为代表的欧洲国家中的工业化现状,总结了热处理材性能改善的原因、环境特性以及性能和用途。图2参26。     

中国林产品质量与标准化研讨会落幕

正2016年9月,"第三届中国林产品质量与标准化研讨会暨木材工业供给侧改革柳州论坛"在广西柳州顺利召开。会议由全国人造板标准化技术委员会、全国木材标准化技术委员会、中国林科院木材工业研究所、柳州市林业局主办,全国人造板标准化技术委员会秘书处、木材所标准化与产业风险研究室、广西林业产业行业协会、广西林产品质量检验检测中心承办。来自全国科研、高校、企业以及当地政府和林业部门的240余名代表出席会议。     

首届全国集成材先进制造技术及应用高峰论坛成功举办

正围绕"生产专业化发展产业化"的主题,首届"全国集成材先进制造技术及应用高峰论坛"2016年9月在山东烟台盛大召开。论坛由我国木材科学与技术的最高专业科研机构——中国林科院木材工业研究所主办,木材所信息中心和威力(烟台)木业技术有限公司承办,山东省家具协会、太尔化工、博海威玛、春喜硬木、普陆洁尘、富士木业协办,以及国家木竹产业技术创新战略联盟、国家人造板与木竹制品质量监督检验中心、全国木材标准化技术委员会、全国人造板标准化技术委员会等单位的大力支持。     

美国的木材保护产业及其标准体系

概述美国木材保护产业的现状,介绍美国木材保护标准体系的基本组成及重要标准,对我国木材保护标准化工作提出建议.     

花卉认证对我国花卉产业发展的影响

论述了花卉认证在中国的发展,从花卉生产、花卉贸易、花卉产业结构调整、花卉产业管理体制与经营机制改革等方面分析了花卉认证对我国花卉产业发展可能产生的影响,建立和实施花卉认证标准和体系将全面提升我国花卉产品的国际竞争力,促进我国花卉产业的健康持续发展.     

热改性木材的加工与应用

热改性木材(炭化木)不仅具有防腐及抗生物侵袭的作用,而且材质稳定,不易变形和开裂.经过热处理的木材具有美观、耐久、环保的特性,适合用作室内外任何实木用途的建材和饰材.目前,芬兰的生产技术较先进;法国、德国等发达国家的技术也具有独特的性质和发展方向.我国的热改性木材加工刚刚起步,目前尚未形成生产规模,且独立开发能力较弱.作者阐述了热改性木材的加工工艺和应用范围,旨在促进我国新产品的研发和利用.     

木材高温热处理技术研究进展

高温热处理技术是木材功能性技术中市场转化率最高和未来前景广阔的主要技术之一,生产过程中不添加化学试剂,在改善尺寸稳定性、生物耐久性、木材材色及声学特性等性能同时不损失产品的环保性能。但高温处理存在木材的力学性能和表面润湿性降低、生产能耗高及废气排放量大等问题,因此了解高温热处理技术对木材材性及性能的影响及作用机理,对进一步提升高温热处理材品质、改进生产工艺和开发新设备具有指导意义。该文综述了高温热处理木材的力学性能、尺寸稳定性、材色、生物耐久性及声学特性等研究现状和作用机理,针对当前生产和研究现状,展望未来高温热处理技术的发展方向和前景。     

2010年热处理（ThermoWood）木材销代强劲回升

总部设在芬兰（Finland）的国际热处理木材协会（International Thermo WoodAssociation,ITWA）公布的生产数据,表明了欧洲（Europe）热处理业务最近的发展。     

《木材工业标准化工作手册》编写

<正>《木材工业标准化工作手册》,由全国木材标准化技术委员会、全国人造板标准化技术委员会、全国林业生物质材料标准化技术委员会、国家林业局林产品质量和标准化研究中心组织编写,定位为木材工业行业标准项目申报、制定、管理、实施的工具书,旨在总结木材工业标准化工作的实践经验,普及标准化工作知识,推动现代木材工业标准化创     

Browsing Damage on Pine (Pinus sylvestris and P. contorta) by a migrating moose (Alces alces) Population in Winter: Relation to Habitat Composition and Road Barriers

In Scandinavia, moose (Alces alces L.) sometimes cause severe browsing damage to economically-important pine. Moose-vehicle accidents have spurred construction of fences along roads, and these may interfere with moose migration between summer and winter ranges, or the road alone may be a barrier. If this happens and moose build up along roads, landowners may suffer economically. Therefore, this study investigated whether roads, fences or other factors influence the use of young pine stands by moose. Eighty stands along roads in northern Sweden were evaluated in which individually-browsed branches were counted on 9972 pines. Moose browsing was not significantly related to birch (Betula pendula Roth, B. pubescens Ehrh.) density, nor did it differ between pines (Pinus contorta Douglas or P. sylvestris L.). However, increased pine density, site productivity and proximity to a highway were associated with increased browsing. Further large-scale studies are needed to understand moose habitat selection and the effects of roads.     

Effects of Root Freezing on the Physiology and Growth of Picea glauca,Picea mariana and Pinus banksiana Seedlings Under Different Soil Moisture Regimes

The root systems of 2-yr-old Picea glauca, Picea mariana and Pinus banksiana seedlings were submitted to various frost temperatures during an artificial frost to induce different levels of root damage. Frost-damaged and control seedlings were placed in a greenhouse under high and low soil moisture regimes. Seedling growth and physiology were evaluated periodically. Seedling survival was reduced when root damage reached levels of 60-80%. Root systems of all three species showed partial to total recovery by the end of the experiment. In general, root freezing damage caused reductions in seedling growth, with these reductions becoming less significant over time. Root damage had little to no effect on black spruce and jack pine seedling physiology, while white spruce CO 2 uptake decreased with increasing root damage. Shoot nitrogen content of all three species decreased slightly with increasing root damage.     

Decomposition and nutrient loss from prunings of different contour hedgerow species in tea plantations in the sloping highlands of Sri Lanka

Contour hedgerows of multipurpose tree species in the sloping tea lands of Sri Lanka are expected to reduce soil erosion and also add significant amounts of plant nutrients to the soil via periodic prunings. The objective of this experiment was to characterize the biomass decomposition pattern and quantify the amount of nutrients added through prunings of six tree species (Calliandra calothyrsus, Senna spectabilis, Euphatorium innulifolium, Flemingia congesta, Gliricidia sepium and Tithonia diversifolia) currently being used in hedgerows associated with tea. Withered leaf and stem prunings (50 g) were enclosed in 2-mm litter bags, placed at 5-cm depth and retrieved after one, three, six, nine and 12 weeks. Loss of initial dry weight, N, P and K was measured. Single exponential decay function adequately described both dry weight and nutrient loss. Tree species differed significantly in their rate of breakdown with decomposition constants (k) varying from 0.0299 to 0.2006 week⁻¹ for leaves and from 0.0225 to 0.0633 week⁻¹ for stems. Gliricidia showed the highest k for leaves with the rest in the following descending order: Senna > Tithonia ≥ Euphatorium > Calliandra > Flemingia. A similar pattern was observed for loss of all nutrients with Calliandra and Flemingia always having lower k values than the rest. Although N immobilization was not observed, immobilization of P and K was observed during the first week of incubation in some species, particularly in stem prunings. Annual biomass of prunings differed significantly between tree species in the following descending order: Calliandra > Senna > Flemingia > Tithonia > Gliricidia > Euphatorium. Calliandra added the greatest amount of nutrients annually to the soil with Euphatorium adding the least. Calliandra prunings provided the annual total K requirement and 49% of the N requirement of mature tea. However, none of the species provided more than 5% of the P requirement. It is concluded that among the tree species tested, Calliandra and Flemingia are the most suitable for contour hedgerows in tea plantations of this agroclimatic region because of their higher soil nutrient enrichment capacity and slower decomposition rates which would minimize leaching losses. This revised version was published online in June 2006 with corrections to the Cover Date.     

Growth of Phlebiopsis gigantea in wood of seven conifer species

Heterobasidion parviporum and Heterobasidion annosum are widely distributed root‐rot fungi that infect conifers throughout Europe. Infection of conifer stumps by spores of these pathogens can be controlled by treating fresh stumps with a competing non‐pathogenic fungus, Phlebiopsis gigantea. In this study, growth of three Latvian strains of P. gigantea and the biological control agent ‘Rotstop’ strain was evaluated in stem pieces of Norway spruce, Scots pine, lodgepole pine, Douglas‐fir, Weymouth pine, Siberian larch and Sitka spruce. The growth rates of one H. parviporum and one H. annosum isolate were also measured in the same stem pieces. The growth rate of P. gigantea varied greatly in wood of different conifer species. It was higher in the three pine species, lower in Norway spruce and lowest in Sitka spruce and Siberian larch, and in Douglas‐fir, this fungus did not grow. The largest area of wood occupied by P. gigantea was in lodgepole pine. Growth of Latvian isolates of P. gigantea in the wood of Pinus and Picea species was comparable to that of the Rotstop isolate. Consequently, stump treatment with local P. gigantea isolates should be recommended. However, our results suggest that Douglas‐fir stump treatment against Heterobasidion by P. gigantea may be ineffective and other stump treatment methods should be considered.     

Effects of Seed Weight and Seed Type on Early Seedling Growth of Pinus sylvestris under Harsh and Optimal Conditions

The effects of seed weight and seed type on seedling growth of Pinus sylvestris (L.) were studied by seeding individually weighed orchard and stand seed in different mixtures under harsh (direct seeding in field) and optimal (seeding in nursery) conditions. In the nursery experiment an increase in the seed weight from 3 to 7 mg increased the seedling height by 10-27% and total weight by 27-113%, and decreased the height/diameter ratio by 5-6% after 2 yrs. With elimination of seed weight effects, orchard seedlings were 2% taller than stand seedlings in year 2. Without elimination of seed weight effects, orchard seedlings were 7-13% taller. In the field experiment an increase in the seed weight from 3 to 7 mg increased seedling height by 18-65%, stem volume by 81-274% and the number of top-buds by 23-34% in year 5. After elimination of seed weight effects, orchard seedlings were 7-13% taller than stand seedlings and without elimination of seed weight effects 20-21% taller after 5 yrs. Even after elimination of both seed weight and genetic effects orchard seedlings were 3-9% larger than stand seedlings in the field experiment. In conclusion, the influence of seed weight and seed type on growth traits and slenderness is highly significant and the influence seems to be greater in harsh conditions.     

Stand Structure in Pine,Spruce and Deciduous Forests: A Comparison Between Finnish and Russian Karelia

This study investigated the stand structure in pine, spruce and deciduous forests in the border district of Finland and Russia. A total of 46 mature forest stands was selected as pairs, the members of each pair being as similar as possible with respect to their forest site type, age, moisture and topography. The stands were then compared between the two countries by means of basal areas and number of stems. The proportions of dominating tree species were 2-12% lower, and correspondingly the proportions of secondary tree species higher, in Russian forests. The density of the forest stock was also higher in each forest type in Russia. The forests in the two countries differed most radically in terms of the abundance of dead trees. The amount was two to four times higher in Russian deciduous and spruce forests, and in pine forests the difference was 10-fold. The stand structures indicated that Russian coniferous stands, in particular, were more heterogeneous than intensively managed pine and spruce stands in Finland.     

Growth and Terminal Bud Formation in Picea abies Seedlings Grown with Alternating Diurnal Temperature and Different Light Qualities

The root collar diameter and the height:diameter ratio are of particular importance in container-grown seedlings where a high density in the containers may produce spindly seedlings. Temperature regimes and light quality are known to affect plant growth. The aim of this study was to identify responses in Picea abies (L.) Karst. seedlings grown with light providing different red:far-red ratios and under temperature regimes with alternating day (DT) and night temperature (NT) from negative (DT < NT) to positive (DT > NT) difference (DIF) between DT and NT. Experiments were conducted in controlled environment chambers and in a daylight phytotron. Only limited thermoperiodic responses appeared in P . abies seedlings with respect to seedling height and dry weight accumulation. The formation of terminal buds, however, was clearly delayed in seedlings grown at negative DIF. The results indicate a requirement for day extension light that is high in far-red, to prevent terminal bud formation under natural short-day conditions. An extended study should be conducted to clarify the minimum level of light intensity and the optimal light quality needed to prevent terminal bud formation under natural short-day conditions.     

CAD与建筑设计的关系

本文分析了CAD在设计中引起的正面和负面影响,并进行了系统的阐述,从而使设计者在应用中能够保持客观的态度。     

Potential to harness superior nutritional qualities of exotic baobabs if local adaptation can be conferred through grafting

Baobab leaves form an important part of the local diet in Sahel countries and elsewhere in Africa. Existing leaf nutritional data and agroforestry performance information are based solely on Adansonia digitata L., the baobab of continental Africa. The introduction potential of Adansonia species from the center of diversity in Madagascar and from Australia remains untapped. To assess this potential, the mineral contents and B₁ and B₂ vitamin levels of dried baobab leaves were determined for five-year old trees of A. digitata, A. gibbosa (A. Cunn.) Guymer ex D. Baum, A. rubrostipa Jum. & H. Perrier (syn. A. fony Baill.), A. perrieri Capuron and A. za Baill. grown in an introduction trial in Mali. Nutritional data were evaluated against survival and vigor to identify promising germplasm. Leaf vitamin and crude protein contents were highest in the Madagascar species, especially A. rubrostipa (B₁ 88 mg 100 g⁻¹, B₂ 187 mg 100 g⁻¹, protein 20.7% dry weight). However, the local species far outperformed the introductions in survival, tree height, basal diameter and resistance to termites. We suggest grafting as a way of harnessing the vigor of well-adapted local baobab varieties to the superior nutritional profiles of A. rubrostipa and others. Cross-species grafting tests in Adansonia were successful, thus creating new agroforestry possibilities with different scion/rootstock combinations.     

Modelling of adequate pretwist for obtaining straight timber

Abstract

Wood in general and wooden studs in particular are often distorted owing to uneven shrinkage during the drying process in the sawmill. Twist is often the most detrimental of all types of distortion, and it is caused by spiral grain in combination with variations in moisture content. For sawmills, the objective is to produce dried, straight boards, and one method of dealing with boards with excessive spiral grain is to sort them out and then dry them in a pretwisted position to obtain straight boards after drying. A model using the finite element (FE) method for the simulation of drying twist distortions was first calibrated against laboratory experiments in which boards were dried with and without restraints and pretwists. After the calibration, the FE results were compared with industrial test results for boards that were dried without restraints or with restraints with zero pretwist, i.e. straight restraints. The FE model used an elastic–ideally plastic material model to obtain permanent deformations. The calibration was to set the yield stresses so that there was a good match between FE results and results from the laboratory experiments. The comparison between the industrial test results and the FE results showed that the FE model is capable of realistic simulations of drying boards with and without restraints and presumably also pretwists.