抽提物对高温热处理材光降解进程的影响

将经3种不同抽提处理的高温热处理欧洲赤松(Pinus sylvestris L.)和山毛榉(Fagus longipetiolata Seem.)木材及其对照材置于氙灯老化箱中加速老化1 008 h,测定老化过程中表面颜色的变化,并使用扫描电镜(SEM)、傅里叶红外光谱(FT-IR)和X射线光电子能谱(XPS)分析老化前后木材表面宏观和微观结构的变化,旨在探究不同抽提物对高温热处理材的光降解进程的影响。结果表明:1)高温热处理材中抽提物的存在有利于缓解其光老化进程,提高热处理材的颜色稳定性;2)碱抽提物对热处理山毛榉表面材色的影响最为显著,其存在有利于延缓老化过程中热处理材表面颜色的变化,苯醇及冷水抽提出的极性抽提物对热处理材的颜色稳定性具有积极作用,冷水抽提后的热处理山毛榉在老化过程中出现射线细胞剥离现象;3)在老化过程中,热处理欧洲赤松的表面颜色变化相对山毛榉大,这是因为热处理欧洲赤松的材色较山毛榉浅,碱抽提物对热处理欧洲赤松颜色稳定性的影响相对较小,而苯醇抽提物及冷水抽出物可提高其耐老化性。     

欧洲赤松的引种栽培

通过欧洲赤松30年的引种试验,结果表明：欧洲赤松在小陇山林区表现出较强的适应性和生长优势.在生长、抗落叶病性状上优于乡土树种油松.麦积植物园30年生欧洲赤松平均树高、胸径分别达13.60m和22.8 cm,生长量与乡土树种油松相当.已完成从种子到种子的引种过程,欧洲赤松在甘肃小陇山引种获得成功.     

第三讲 林木产地试验

林木产地试验是指在一个树种的自然分布范围内,把各生态区的种子或苗木集中在一点或多点进行造林试验,以探明该树种在不同产地的遗传变异特点和增产效益,从而为确定最适种源划定种子调拨区,为合理组织种子供应、种子园和母树林基地建设提供根据。林木产地试验是重要的育种措施之一,已有悠久的历史。法国的德·蒙素从1821年就进行了欧洲赤松产地试验。以后,对欧洲赤松、欧洲云杉等曾组织过     

清原地区引种欧洲赤松造林试验初报

为了丰富辽东山区的造林树种，在辽宁省清原地区进行了欧洲赤松的引种栽培试验，结果表明，13年生欧洲赤松的树高、胸径分别为9.9m，6.3cm，均高于樟子松，红松，与长白落叶松之间的差异不显，说明欧洲赤松在清原地区已经引种成功，可以扩大栽培。     

世界林木遗传改良研究水平与趋向

一、国内外水平比较 (1)种源试验研究 一般把法国学者ph.A.De.Vilmorin 1821年开展的欧洲赤松种源研究作为林木遗传研究的先驱。这一试验是为了回答同一树种不同地方群体存在的差异是否由遗传控制、有无利用价值而设置的。1879年德国学者通过对同一树种     

接种菌根菌对桉树生长的影响

以尾叶桉和巨尾桉为材料 ,1993和 1994年在广东省开平市镇海林场建立了 2个外生菌根菌接种试验 ,均采用裂区设计 ,4次重复 ,每试验均 2个树种为主区 ,菌根菌处理为副区。试验 1有 8个外生菌根菌处理 ,每处理小区 6株或 9株 ,试验 2有 3个外生菌根菌处理 ,每处理小区 9株。造林后 ,定期观测树高、地径或胸径。试验结果表明 :树种内菌根菌效应分析发现 ,巨尾桉所有指标在菌根菌间存在显著差异 ,尾叶桉只是某些指标在菌根菌间有显著差异 ,表明两树种对相同菌根菌处理的反应不同 ;树种联合方差分析表明 ,试验 1中所有指标在区组间、树种间、菌根菌处理间均有显著差异 ,从方差分量看 ,树种效应 >树种×菌根菌互作效应或菌根菌效应 ;试验 2中树高指标在树种间和菌根菌处理间均存在显著差异 ,而 2 4个月时胸径指标在树种间无显著差异 ,但胸径在菌根菌处理间有极显著差异 ,树高指标的方差分量为树种效应 >树种×菌根菌互作效应或菌根菌效应。胸径的方差分量为菌根菌效应 >树种×菌根菌互作效应 >树种效应。分析表明树种×菌根菌互作效应存在时间上的不稳定性 ;同时 ,讨论了外生菌根菌应用中树种因素的重要性。     

牡竹属10种竹叶矿质元素含量分析

为了明确牡竹属竹叶中矿质元素的组成,采用ICP-MS法测定了牡竹属10种竹叶中主要矿质元素的含量。结果表明,10种竹叶中含有丰富的矿质元素,其中K、Ca、Mg含量较高,其次是Mn、Fe、Al、Na、Zn元素,Cr、Ni、Cu元素在竹叶中的含量较少,Co、As、Se、Mo、Hg和Pb含量很低。研究结果为牡竹属竹叶的开发利用提供了科学依据。     

欧洲种子园的球果和种子害虫及其防治

欧洲森林树木种子园大多是在第二次世界大战后建立起来的。实际上在七十年代才收获第一批种子。大多数欧洲国家希望到本世纪末种子园将能供应造林所需的全部种子。欧洲种子园的主要树种有欧洲赤松(Pinussilvestris L.)、欧洲云杉(Picea abies(L.)Ka-rst)、落叶松和冷杉(Abies spp)等。外来树种有美加黄杉、扭叶松和锡特加云杉等。欧洲赤松的最有害的虫种是松球果象虫(Pissodes val-idirostris Gyll.),球果被害率有时可达25～     

瑞典的林木种子园

瑞典的林木种子园发展很快。现在种子园内生长有欧洲赤松(540公顷)、云杉(229公顷)、落叶松(35公顷)和扭叶松(31公顷)。阔叶树种子园有:夏橡(7公顷)、山毛榉(5公顷)和疣皮桦(2公顷)。在最近5—7年内,种子园面积计划增加2—3倍。欧洲赤松最大的已有36年,大部分是     

氮肥对盆栽欧洲水青冈生物量和营养分配的影响(英文)

调查了施加氮肥(15NH4和15NO3)处理后在两个连续生长季内欧洲水青冈(Fagus sylvatica L.)幼苗地上部分和地下部分的生物量和营养元素分配。盆栽欧洲水青冈幼苗培养于温室大棚内,培养土样取自相邻的三种林分:欧洲水青冈,挪威赤松,欧洲水青冈-赤松混交林。结果表明,氮肥(15N)处理对欧洲水青冈营养元素分配没有显著影响,施加氮素形式决定自身流入植物库的情况。欧洲水青獭收氮素主要以硝态氮的形式,因此,尽管植物体内保存的硝态氮和氨态氮并没有统计差异,但是叶片中硝态氮明显减少。施加硝态氮对欧洲水青冈氮素恢复的影响要大于施加氨态氮。与欧洲水青冈茎、粗根相比,优质根系对氮素(15N)固定是一个缓慢过程。表8图1参40。     

Impregnation of Scots pine and beech with tannin solutions: effect of viscosity and wood anatomy in wood infiltration

The impregnation process of Scots pine and beech samples with tannin solutions was investigated. The two materials involved in the process (impregnation solution and wood samples) are studied in depth. Viscosity of mimosa tannin solutions and the anatomical aspect of beech and Scots pine were analysed and correlated. The viscosity of tannin solutions presents a non-newtonian behaviour when its pH level increases, and in the case of addition of hexamine as a hardener, the crosslinking of the flavonoids turns out to be of great importance. During the impregnation of Scots pine (Pinus sylvestris L.) and beech (Fagus sylvatica L.), the liquid and solid uptakes were monitored while taking into consideration the different conditions of the impregnation process. This method allowed to identify the best conditions needed in order to get a successful preservative uptake for each wooden substrate. The penetration mechanism within the wood of both species was revealed with the aid of a microscopic analysis. Scots pine is impregnated through the tracheids in the longitudinal direction and through parenchyma rays in the radial direction, whereas in beech, the penetration occurs almost completely through longitudinal vessels.     

固化干燥条件对CCA-C处理(北美)红松和南洋松木材的固化速度和流失特性的影响(英文)

该文使用 6 4kg·m-3 的CCA C木材防腐剂 ,在 11个后处理基准 (其温度为 5 0℃～ 70℃和 5个不同的相对湿度 )条件下 ,研究了固化干燥条件对处理北美红松和南洋松木材的固化速度和化学元素的流失的影响 .实验样品内的液体通过挤压方法被定期检测并分析其六价铬的含量 .调节固化后的样品按美国木材防腐协会E11 97标准进行流失实验 .一般情况下 ,对于大多数基准 ,红松固化比南洋松少、快 ,并且高温高湿的固化条件比低湿度的固化条件导致较快的固化速度和较少的铬和砷的流失 .对于2个材种在 11个固化干燥条件下 ,铜元素的流失没有很大的差异 .所有的CCA化学元素的流失情况 ,红松比南洋松更明显 .更进一步的工作需要CCA处理大尺寸样品 ,优化干湿球温度差 ,以便考察其固化干燥条件对流失的影响     

Impact of fixation/drying conditions on fixation rate, leachability and bioefficacy in CCA-C treated red pine and southern pine

Red pine (Pinus resinosia Ait) and southern pine (Pinus spp.) sapwood blocks were pressure treated with CCA-C at retention of 6.4, 2.0, 1.5 kg?m-3 followed by fixation using 11 post-treatment schedules ranging from 50-70 °C and 5 different relative humidity conditions. The effect of these post-treatment schedules on fixation rate, chemical leachability and decay resistant once were evaluated to better understand the effects of fixation/drying conditions on leachability and biodeterioration. Southern pine blocks fixes slightly slower than red pine. Fixation of CCA at high temperature high humidity, essential initially fixation at high humidity for fixation/drying schedules, resulted in lower leaching of chromium and arsenic elements than high temperature low humidity or initially fixation at the high temperature low humidity conditions. Copper leaching was indicated no significant difference under 11 fixation/drying conditions for both species. Weight losses for southern pine by Chaetomium globosum was lower than red pine by Gloeophyllom trabeum. There were some different capacities of decay resistance for both species under those post treatment conditions.     

Termite resistance of DMDHEU-treated wood

Four field trials were conducted with wood modified with dimethyloldihydroxy-ethyleneurea (DMDHEU) in contact with subterranean termites. Trials 1 to 3 were conducted with Coptotermes acinaciformis (Froggatt); 1 and 2 in south-east Queensland, and 3 in northern Queensland, Australia. Trial 4 was conducted in northern Queensland with Mastotermes darwiniensis (Froggatt). Four timber species (Scots pine, beech, Slash pine and Spotted gum) and two levels (1.3 M and 2.3 M) of DMDHEU were used. The tests were validated. DMDHEU successfully prevented damage by C. acinaciformis in south-east Queensland, but not in northern Queensland. It also did not protect the wood against M. darwiniensis. Except for beech in trial 4, DMDHEU led to reduced mass losses caused by termite attack compared to the unmodified feeder stakes. Slash pine (in trials 1 and 3) and Spotted gum (in trial 1) presented low mass losses. Modification of Scots pine was more effective against termite damage than the modification of beech.     

Effects of thinning and canopy type on growth dynamics of Pinus sylvestris: inter-annual variations and intra-annual interactions with microclimate

We assessed the effects of thinning (0, 20 and 30 % extraction of basal area) and canopy type (pine–beech vs. pine plots, beech accounting for 12 % of total basal area) on radial growth of dominant and codominant Scots pine at inter-annual scale and on microclimatic conditions, radial growth and xylogenesis 9 years after thinning at intra-annual scale. Thinning weakly affected pine growth, which was enhanced 3 years after harvesting. Over time, a gradual reduction in pine growth in mixed canopy relative to pure canopy occurred only in unthinned plots apparently due to beech expansion. Indeed, 9 years after thinning, a higher seasonal radial increment and a greater number of tracheids were produced under pine canopy in the unthinned plots, whereas no differences between canopy types were observed in the thinned plots. Radial increment and tracheid production were mainly affected by tree water status (air and soil humidity, throughfall). The differences of tree water status caused by treatments, and plausibly disparities in tree size and tree-to-tree competition, were the main drivers explaining the patterns observed for radial increment and xylogenesis. Our results suggest that the negative effects of beech competition on Scots pine growth in similar mixed forest may be controlled to some extent by thinning.     

Kinetics of wood degradation by fungi with x-ray microdensitometric technique

Summary X-ray microdensitometric analysis was employed for the detection of fungi attack in wood of pine and beech in comparison with the studies of specimen weight loss tests. Two species of fungi were used:Gloeophyllum trabeum (Pers.:Fr. Murrill) andTrametes versicolor (L.:Fr. Pilat). We select these species to induce typical decay attack mainly on cellulose in pine (brown rot) and mainly on lignin in beech (white rot). The attack was conducted for 1, 2, 3, 4 and 5 months in sterile laboratory conditions. After 5 months all the values of density components decreased. In beech the loss was of about 25% for all components. In pine the decreasing of the earlywood density component was of about 10% and in latewood of about 22%. The corresponding mass density losses, determined by gravimetric method, were approximately 18% for beech and 16% for pine.The authors wish to thank la Région Rhône - Alpes, Lyon, France for the financial support of this research     

Chemical aspects of wood modification by sol�Cgel-derived silica

It has been shown that tetraethoxysilane-derived precursors are suitable solutions for impregnating pine sapwood to improve its dimensional stability. Tailored sol?Cgel syntheses result in precursors with nano-scaled silica species which are able to penetrate into the cell walls of wood. The physical fixation of those species inside the cell walls was verified by ESEM/EDX investigations. There is evidence that the silica species are chemically bonded to wood components. Non-reacted alkoxy groups can exist in the wood composites after impregnation. The amount of these organic residues depends on the composition of the precursors, especially their condensation degree and reactivity. Treatments for finishing the composites after the impregnation step to get clean products and stable properties are discussed in this context. An explanation of the complex relationship between solids content in the impregnation solutions and percentage weight gain and bulking of the composites is given. It can be demonstrated that high WPG values (>20?%) are pre-conditions for an effective protection of the resulting composites but they only guarantee efficient improvements if connected with the incorporation of the inorganic component inside the cell walls. Therefore, the sol?Cgel syntheses have to be carried out in such a manner that very small (<2?nm) as well as reactive species are sufficiently available. This demands syntheses using sub-stoichiometric water contents (H₂O/TEOS?<?4, better <2).     

Impact of fixation/drying conditions on fixation rate, teachability and bioefficacy in CCA-C treated red pine and southern pine

Red pine (Pinus resinosia Ait) and southern pine (Pinus spp.) sapwood blocks were pressure treated with CCA-C at retention of 6.4, 2.0, 1.5 kgm^-3 followed by fixation using 11 post-treatment schedules ranging from 50–70 °C and 5 different relative humidity conditions. The effect of these post-treatment schedules on fixation rate, chemical leachability and decay resistant once were evaluated to better understand the effects of fixation/drying conditions on leachability and biodeterioration. Southern pine blocks fixes slightly slower than red pine. Fixation of CCA at high temperature high humidity, essential initially fixation at high humidity for fixation/drying schedules, resulted in lower leaching of chromium and arsenic elements than high temperature low humidity or initially fixation at the high temperature low humidity conditions. Copper leaching was indicated no significant difference under 11 fixation/drying conditions for both species. Weight losses for southern pine byChaetomium globosum was lower than red pine byGloeophyllom trabeum. There were some different capacities of decay resistance for both species under those post treatment conditions.     

Modification of three hardwoods with an N-methylol melamine compound and a metal-complex dye

This study evaluated the combined modification and staining of ash, beech and maple wood with a low molecular weight N-methylol melamine compound (NMM) and a metal-complex dye. Wood samples were treated with aqueous solutions of 10, 20 and 30 wt% NMM and 5 wt% of the dye. The treatment caused the fixation of the water-soluble dye by the NMM resin. Vacuum pressure impregnation of unsealed wood blocks did not result in different solution uptake and weight percent gain after curing among the three species, but sealing of the surfaces of the wood blocks to allow penetration only into one direction revealed easiest penetrability of beech followed by maple and ash. UV micro-spectrophotometry and light microscopy indicated that NMM was partly deposited in the cell wall and partly in the lumens. Penetration of the metal-complex dye was shown by means of X-ray micro-analysis (SEM–EDX). The study shows that a combined resin modification and staining of the three wood species tested is possible and that NMM causes fixation of the water-soluble dye.     

纳米TiO2改性薄竹的工艺试验

研究了纳米TiO2改性薄竹机理与工艺,分析薄竹切面、薄竹厚度、浸渍压力与浸渍时间等工艺因素对薄竹附载TiO2效果的影响,并运用X射线光电子能谱与环境扫描电镜技术手段,分析了薄竹改性处理前后的表面元素组成、元素变化、TiO2分布效果。试验结果表明:浸渍时间90 min、浸渍压力0.10 MPa、薄竹厚度0.3 mm、径切面纹理的薄竹、纳米TiO2溶液浓度0.5 g/L、浴比1∶10～20、常温浸渍纳米TiO2溶液改性薄竹工艺是可行的,TiO2附载率约为1.3%。