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1.
  • ? Decay resistance of larch (Larix sp.) to fungi was evaluated on heartwood samples belonging to 3 species (L. decidua, L. kaempferi and their hybrid), 3 races of European larch (polonica, sudetica and alpine), 13 wood lots (populations) and 313 trees.
  • ? Larch wood appeared, on average, as moderately durable although a high variability was observed. At the sample level as well as at the mean individual tree level, durability ranged from class 1 to 5 according to EN 350-1 standard. At the population level, larch wood varied from ‘durable’ to ‘slightly durable’. Genetics played a major role in decay resistance at the species, provenance and tree levels. Environmental factors such as the position of heartwood samples and the age of trees were also identified as a source of variability.
  • ? The most durable wood was not necessarily from old native alpine stands of European larch: some young larches from faster growing lowland origins also produced durable wood.
  • ? Genetic improvement of larch wood durability appeared therefore likely by the selection of the best populations for decay resistance as well as from the selection of individuals.
  •   相似文献   

    2.
    《林业研究》2021,32(1)
    Tachi-branco(Tachigali vulgaris,L.F.Gomes da Silva H.C.Lima) is a leguminous tree species native to the Amazon rainforest that has drawn attention for its remarkably fast growth,a required trait for biomass/bioenergy plantations.In evaluations of biomass production and wood properties of T.vulgaris planted in homogeneous plantations at different spacings in the Amazonian state of Para,Brazil,biomass of 7-year-old trees was quantified for individual trees and the entire population.Wood was also sampled to assess properties relevant to bioenergy applications.The choice for spacing dimension for planting nonclonal T.vulgaris should consider whether the priority is greater productivity per tree,achieved with greater spacings(9.0 m~2 and 12.0 m~2),or productivity per area,achieved with closer spacings(6.0 m~2 and 7.5 m~2).Genetic variability of the T.vulgaris seed stand and/or high heritability of wood traits overcame the effect of different spacing on all morphological,physical,chemical and energetic properties of T.vulgaris wood.This species has moderate basic density when cultivated at spacings larger than 6 m~2 and net heating value above 7.95 MJ/kg,which is suitable for bioenergy purposes.The high variation in wood properties within tree spacing is strongly indicative of great potential for genetic breeding.The fast growth and the suitable moderate wood basic density confirm the outstanding potential of homogeneous plantations of T.vulgaris for providing wood for bioenergy.  相似文献   

    3.
    木材材色研究进展   总被引:1,自引:0,他引:1  
    木材材色是木材基本属性,关乎木质品视觉美感及其装饰性能,其色彩变化是评价木材品质及其市场价值的重要指标。木材材色的形成及其影响因素是用材树种良种选育、人工林定向培育及木材加工利用的研究热点。文中综述木材材色分析技术,介绍现行的材色分级标准,阐释材色形成机理和变异来源,并面向未来木材市场需求及高价值人工林定向培育目标做出展望,以期为今后木材材色形成机理和实木用材树种良种选育、优质木材定向培育及加工利用等相关研究提供参考。  相似文献   

    4.
    利用电脑技术,构建植物电子图像标本数据库软件,在野外工作中可以方便地查阅植物形态标本资料。文章就构建植物分类鉴定信息、树种营造林信息以及信息录入、查找功能的植物电子图像标本和造林树种档案数据库作了简要介绍。  相似文献   

    5.
    以广西黄冕林场的几个桉树树种为研究对象,对比分析不同树种生长、立木材性以及林分密度对其影响。结果表明:各树种的生长(树高、胸径、单株材积、冠幅、树皮厚度)和材性(立木Pilodyn值、应力波波速、基本密度)性状均差异显著。比较3种不同林分密度的邓恩桉发现,林分密度对其生长、材质形成等产生显著影响,适宜的林分密度有利于林木生长和材性形成。对各性状采用主成分分析法进行了树种评价,结果表明:巨桉林木生长量大,大花序桉和本沁桉生长量相对较少,但木材材质相近,表现为坚硬,而粗皮桉、柳桉、邓恩桉均低于对照尾巨桉。从林木生长、立木材性方面看,适合于该地区发展的树种有巨桉、大花序桉和本沁桉,其中巨桉最适宜。  相似文献   

    6.
    Saproxylic beetles are highly sensitive to forest management practices that reduce the abundance and variety of dead wood. However, this diverse fauna continues to receive little attention in the southeastern United States even though this region supports some of the most diverse, productive and intensively managed forests in North America. In this replicated three-way factorial experiment, we investigated the habitat associations of saproxylic beetles on the coastal plain of South Carolina. The factors of interest were forest type (upland pine-dominated vs. bottomland hardwood), tree species (Quercus nigra L., Pinus taeda L. and Liquidambar styraciflua L.) and wood posture (standing and downed dead wood, i.e., snags and logs). Wood samples were taken at four positions along each log and snag (lower bole, middle bole, upper bole and crown) ∼11 months after the trees were killed and placed in rearing bags to collect emerging beetles. Overall, 33,457 specimens from 52 families and ≥250 species emerged. Based on an analysis of covariance, with surface area and bark coverage as covariates, saproxylic beetle species richness differed significantly between forest types as well as between wood postures. There were no significant interactions. Species richness was significantly higher in the upland pine-dominated stand than the bottomland hardwood forest, possibly due to higher light exposure and temperature in upland forests. Although L. styraciflua yielded more beetle species (152) than either Q. nigra (122) or P. taeda (125), there were no significant differences in species richness among tree species. There were also no relationships evident between relative tree abundance and observed or expected beetle species richness. Significantly more beetle species emerged from logs than from snags. However snags had a distinct fauna including several potential canopy specialists. Our results suggest that conservation practices that retain or create entire snags as opposed to high stumps or logs alone will most greatly benefit saproxylic beetles in southeastern forests.  相似文献   

    7.
    We assessed growth traits and wood properties of DH 32-29, a clone of Eucalyptus urophylla × E. grandis, at age of two to six years in Guangdong in China. Analysis of variance of studied traits showed that there were significant differences (1% level) on all studied traits among ages except for wood basic density. Analysis of age trends of growth traits and wood properties revealed that rotation length of DH32-29 should be more than six years or longer. Phenotypic correlations among traits at individual ages indicated that correlations between growth traits were strongly positive. There was significant change in relationship between growth and wood basic density with increasing age, ranging from -0.03 to -0.54 at 2 and 5 year and 0.003 to 0.3 at 3, 4 and 6 year.Correlations between Pilodyn pin penetration and basic density measuredon increment cores showed that Pilodyn could rank or group genotypesor sites into density classes, but failure to predict individual tree and individual clone.  相似文献   

    8.
    采集了4168株编表样木数据,按原林业部"林业基础数表标准化技术业务组"推荐的"可变出材率表"的编制方法,利用样木的测径数据建立削度方程,编制了黑龙江市县林区主要树种一元材种出材率表。经检验,本出材率表精度较高、适用性强,可供生产经营单位、管理部门和科学研究使用。  相似文献   

    9.
    瘿木是制作家具、工艺品的珍贵木材, 装饰性强, 商业价值高。文中通过调查可形成瘿木的树种及成因、材质特点及利用现状, 对瘿木的研究与利用进行了展望。调查发现有32科52属100余种瘿木树种, 树种丰富; 根癌农杆菌Agrobacterium tumfaciens、真菌、冻伤和林火等可使树木结瘤, 根癌农杆菌和冻伤使树木结瘤的过程都与树木形成层细胞的基因变异有关。目前已知几种瘿木的密度、尺寸稳定性和断裂能较正常材高; 几种瘿木木质素含量增加, 纤维素含量降低, 多种抽提物含量增加, 细胞形态变异。文中认为人工培育瘿木可尝试选择树龄较大的林木, 以真菌或细菌病原接种、低温刺激及火烧等方法促进其结瘤。  相似文献   

    10.
    人工林杨木木材强化研究发展现状及趋势   总被引:2,自引:0,他引:2  
    分析了人工林主要树种杨木的发展情况以及国内外木材强化研究技术的概况和研究进展,为更好地研究人工林杨木强化技术提供借鉴.  相似文献   

    11.
    THE EFFECT OF HEAT TREATMENT ON DIFFERENT SPECIES WOOD COLOUR   总被引:2,自引:0,他引:2  
    Woodisnaturalmaterial,naturegivewoodsurfacecolor,g]oss,grain,qualitysenseetc-,whichconsititutedwoodaesthet-icfeeling.Forthisreson,peoplealwaysusedwide]ywoodtomakefurnitureanddecorating,andstlldiedonthequntitativetestingofwoodsurfacevisualphysicalmagnitude.tl-8jTreeswereprocessedoperationbyaseriesofworkingprocesstoformthewoodsurfacewhichwesawandtouchedonfur-nitureanddecorating.Inthesekindsofworkingprocess,whetherthevisualphysi-calmagnitudeofwoodsurfacehadvaria-tionsorthisvariationschangedwoodna…  相似文献   

    12.
    桉树不同地理种源木材构造性质比较研究   总被引:4,自引:0,他引:4       下载免费PDF全文
    在海南省琼海市,中国林业科学研究院热带林业研究所按树种源试验林内,采集了巨桉,柳桉,赤桉和尾叶桉44个种源的木材试材,对木材解剖了分子和基本密度进行了研究和评优,从中选出巨桉14860、14849、14509,柳桉14429,14435、14527;赤桉12187、15050、15062和尾叶桉15089为最优种源。  相似文献   

    13.
    长江滩地立木腐朽杨树与正常杨树生长与材性的比较研究   总被引:1,自引:0,他引:1  
    王朝晖  费本华  任海青  郝刚 《林业科学》2001,37(5):113-119,T002
    本文对长江滩地意杨的生长和木材材性进行了初步研究,着重讨论长江滩地立木腐朽杨树与正常杨树在树高、胸径生长的差异,通过回归分析,给出了杨树胸径生长与年龄的回归方程。分析研究腐朽木和正常木在年轮宽度、含水率、木材密度、干缩率等方面的差异。通过扫描电镜观测腐朽木和正常木细胞壁层的差异和菌丝在木材细胞的分布状况。研究结果表明:地势低是导致杨树立木腐朽的直接原因;腐朽对杨树的胸径生长和高生长及木材材性有显著影响;腐朽材内部生材含水率远低于正常材内部生材含水率,这是由于腐朽杨树内部导管比量明显比正常材低导致其输导水分功能减弱所致;而腐朽材的密度和干缩率均高于正常材;腐朽木中出现了具有应拉木特征的区域,菌丝入侵立木杨树主要通过夹皮裂隙,然后通过导管和木射线细胞向木纤维中扩散。  相似文献   

    14.
    In close-to-nature silviculture one strives to derive the advantages of the natural adaptations of tree species to different growth conditions. Evidence of the natural distribution of tree species is obtained through vegetation science (recent ground vegetation, primeval forest relicts), studies of old written sources, and pollen and macrofossil analyses. Here we have analysed macrofossil samples of charcoal kiln sites and the recent ecological conditions in the vicinity of these sites, as well as secondary written sources on forest and land-use history. From charcoal analysis of kiln sites we were looking for spatial patterns of past tree species exploitation, with special regard to regional and local differences in the forest growth conditions and the natural wood supply. Therefore, we selected remote forest areas characterised by a high density of kiln sites and significant differences in the ecological conditions. The sample sites ranged over a landscape profile of 40 km, covering many ecological site types. The anthracological results of 181 post-medieval kiln sites were evaluated, considering two spatial scales: the total 40-km profile and a fine-scale profile of 4 km. Considering the charcoal material analysed as a whole, all of the tree taxa to be expected based on the natural conditions were found. The frequencies of the exploited taxa also reflected a natural situation. Wood of the climax vegetation, Fagus, Abies and Picea, was mainly used and all other taxa were quantitatively unimportant. The results for the individual sites showed considerable differences in taxa composition, from which regular spatial patterns of the past tree species distribution were deduced. These regional and local patterns are explained by natural differences in the ecological conditions in the vicinity of the sample sites. At the same time, new indications of the natural tree species composition of our forests are inferred. A pronounced dependency of charcoal production on the local natural wood supply is discernible. No indications of tree species selection or forest degradation could be found.  相似文献   

    15.
    采用我国木材化学成分分析国家标准,对湖南40种主要树种木材的化学成分组成进行了分析测定.并结合各树种木材的化学成分及其性质,对其在工业方面的开发利用进行了探讨.所测得的数据,可供各地开发利用各种木材作为参考.  相似文献   

    16.
    Wood specific gravity of some tree species in the Garhwal Himalayas,India   总被引:2,自引:2,他引:0  
    Estimation of terrestrial biomass depends critically on reliable information about wood specific gravity of forest trees. In recent years, wood specific gravity has become more important when exploring the universality of functional traits of plants and estimating their global carbon stocks. To estimate their specific gravity, wood samples were collected from a total of 34 tree species, 30 from lower elevations and 4 from upper elevations in the Garhwal Himalayas, India. The results show that the average wood specific gravity was 0.631 (ranging between 0.275 ± 0.01 and 0.845 ± 0.03) for the species at lower elevations and 0.727 (ranging between 0.628 ± 0.02 and 0.865 ± 0.02) for the upper elevations. The average wood specific gravity for the upper elevation species was 9.6% greater than that for the species at lower elevations. Aegle marmelos among the lower elevation species and Quercus leucotrichophora among the upper elevation species had the highest wood specific gravity, which were 0.845 ± 0.03 and 0.865 ± 0.02, respectively.  相似文献   

    17.
    The effect of stand density (1000 stems/ha, 500 stems/ha and 250 stems/ha) on tree growth and wood quality characteristics was studied in a 27-year-old plantation species of Populus xiaohei in China. Results indicated that stand density had significant effects on tree radial growth and crown size, and the lowest stand density produced trees with the largest stem taper. In terms of wood quality characteristics, there was no significant effect of stand density on either wood basic density or fiber length. However, significant differences were found between different stand densities for wood mechanical properties. A positive relationship between modulus of elasticity, compression strength and stand density was observed, while the highest modulus of rupture was recorded at a moderate density of 500 stems/ha. Stand density was responsible for highly significant effects on both juvenile wood and wet heartwood basal areas in individual trees, and there was an obvious tendency towards increasing juvenile wood and wet heartwood basal areas with decreasing stand density. In addition, the relationships between wood quality characteristics and tree and stand characteristics were also examined. Some wood quality characteristics, namely mechanical properties and juvenile wood and wet heartwood basal areas, were quantified successfully in relation to selected tree characteristics using a regression approach with various degrees of goodness of fit. Based on comprehensive consideration of various factors, such as wood quality, tree growth, and establishment cost, results from this study suggest that a density of 500 stems/ha is optimum for wood production.  相似文献   

    18.
    Inttxiducti()nSnagandfaIlenwoodwasin1ps)rtantcolllponel1tSofft)restecosystem,nutrientpoolf`'rforestal1in1alsal1dn1icrobes,alsowashoPortantapproachofe11ergyflowa11dmaterialnowinforest.soforestecoIogistsattachedinlportaI1cetostudyonsnagandfallel1woodil1creasinglya11dl1ewlydevelopedd1e"ECologyofWood`lecomPOsitiol1'{"'l.Inresearchworkli1Olal1gbaiMoul1tainForestEcosys-tem,tllestudyl4,7,s,9,1o]lladbeenco11ductedinfallel1woodsince8os,andtheresearchra11gewasverywidespread.Buttl1esestUdieswerenl…  相似文献   

    19.
    Functional convergence in hydraulic architecture and water relations, and potential trade-offs in resource allocation were investigated in six dominant neotropical savanna tree species from central Brazil during the peak of the dry season. Common relationships between wood density and several aspects of plant water relations and hydraulic architecture were observed. All species and individuals shared the same negative exponential relationship between sapwood saturated water content and wood density. Wood density was a good predictor of minimum (midday) leaf water potential and total daily transpiration, both of which decreased linearly with increasing wood density for all individuals and species. With respect to hydraulic architecture, specific and leaf-specific hydraulic conductivity decreased and the leaf:sapwood area ratio increased more than 5-fold as wood density increased from 0.37 to 0.71 g cm(-3) for all individuals and species. Wood density was also a good predictor of the temporal dynamics of water flow in stems, with the time of onset of sap flow in the morning and the maximum sap flow tending to occur progressively earlier in the day as wood density increased. Leaf properties associated with wood density included stomatal conductance, specific leaf area, and osmotic potential at the turgor loss point, which decreased linearly with increasing wood density. Wood density increased linearly with decreasing bulk soil water potential experienced by individual plants during the dry season, suggesting that wood density was greatest in individuals with mostly shallow roots, and therefore limited access to more abundant soil water at greater depths. Despite their taxonomic diversity and large intrapopulation differences in architectural traits, the six co-occurring species and their individuals shared similar functional relationships between all pairs of variables studied. Thus, rather than differing intrinsically in physiological responsiveness, the species and the individuals appeared to have distinct operating ranges along common physiological response curves dictated by plant architectural and structural features. The patterns of water uptake and access to soil water during the dry season appeared to be the main determinant of wood density, which constrained evolutionary options related to plant water economy and hydraulic architecture, leading to functional convergence in the neotropical savanna trees studied.  相似文献   

    20.
    Plantations of tropical species are becoming an increasingly important source of wood.However, it is important that research trials focus not only on tree growth performance, but also on wood quality.The aims of this study were to assess the growth performance of six commercially and ecologically important tree species from separate plantation trials in Indonesia and to determine the relationships between tree growth and wood quality in terms of the dynamic modulus of elasticity(MOE) and wood density.Forty-eight 7-year Maesopsis eminii Engl.and thirty-five 9-year specimens(7 each of 5 Shorea spp.)were selected from two trials.The MOE, based on acoustic velocity, was indirectly measured to evaluate wood stiffness.Tree-growth performance was evaluated, and correlations between growth traits and acoustic velocity as well as density and wood stiffness properties were estimated.The growth performance of M.eminii in terms of tree volume was significantly different in three different categories of growth(i.e.fast, medium, slow).Of the five Shorea spp.studied, Shorea leprosula Miq.had the highest growth rate, as expected since it is known to be a fastgrowing Shorea species.Indirect measurement of wood quality by means of non-destructive ultrasonic methods showed a weak negative correlation between tree volume and acoustic velocity and dynamic MOE.Although each fast-growing tree could reach a merchantable size faster than other varieties or species, wood traits of various species tested were not significantly different based on tree growth rate performance.The findings from this study could be used to improve selection criteria in future breeding trials; indirect measurements of the dynamic modulus of elasticity can be used in mass pre-selection of genetic materials, to choose the most-promising material for in-depth evaluation.  相似文献   

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