移动式炭化炉的应用

在伐区,3cm以上的枝丫占木材采伐量的16.5％,黑龙江省林区每年可产枝丫165万m~3。目前,除部分用于削片和烧材外,每年尚有120万m~3的枝丫有待开发利用,而移动式炭化炉烧木炭为枝丫利用开辟     

谈林区以煤代木的经济效果

带岭林业实验局在实现全局不烧好材、烧枝丫的基础上,于一九八○年第四季度开展了改革炉灶、以煤代木试点。时间虽短,效果显著。一、剩余物的经济价值三个剩余物,烧之可惜,用之为宝。据我们对该局烧柴站的枝丫和贮木加工厂的板条、木头头经济价值测算,如表1:     

搞好伐区剩余物生产是缓解林业“两危”的主要途径之一

据伊春林区调查,仅有85％的小规格材和60％的枝丫材运出伐区利用,其余部分都遗弃在伐区。伊春林区一年约有60多万 m~3的采伐剩余物,所以搞好伐区剩余物生产具有重要意义。伐区剩余物利用的主要途径有小规格材的加工利用、枝丫材生产和利用、发展林化产品、改革烧材结构等。     

利用果树枝丫材制造刨花板

利用果树枝丫材制造刨花板希腊亚里士多德大学林学院试验用果树枝丫材制造刨花板获得成功。实验中压制单层和三层结构刨花板，枝丫材和成材的重量比分别为１００：０，７５：２５，５０：５０，２５：７５及０：１００。试验结果表明，对三层结构刨花板而言，芯层枝丫材的...     

双杆捆拖式集枝丫新工艺的研究

为提高集枝丫效率，降低集枝丫成本，把短小枝丫也集下山，改造了Ｊ－５０拖拉机横背枝丫的传统集枝工艺，研究出双杆捆拖式集枝丫新工艺，本文介绍了该新工艺的结构原理、使用过程，并通过实践总结了其优点，分析了经济效益。     

枝丫材占采伐量比重的调查

枝丫材是林产工业的重要原料。为了摸清我局的枝丫材资源,使我局能够更为合理地确定枝丫材利用规模,我们对枝丫材占采伐量的比重进行了调查。一、技丫材我们这次调查的枝丫材包括:(1)小头直径为4—8厘米的枝丫;(2)小头直径为表1 皆伐伐区枝丫材占采伐量的比重     

解决群众烧柴问题小议

中共中央、国务院《关于保护森林发展林业若干问题的决定》中第十二条指出:努力改变林区烧好材的习惯,号召林区职工,社员群众,以及机关、部队、学校、厂矿企业等单位都应烧枝丫、茅柴。有条件的地方应当实行以煤代木;发展沼气和小水电站等,大力节约木材。同时,要采取经济补贴的办法,鼓励林区的单位和群众不烧好材。林区广大群众应以实际行动响应党中央的号召,积极发展薪炭林,保护好绿色能源。一、群众烧柴难的问题应列入党的议事日程我区46万农户,烧柴难的农户达70%     

东北林区枝丫材生产的调查报告

枝丫是森林资源的重要组成部分。随着生产技术的进步和对木材产品需要量的不断增多,如何利用枝丫,日益引起人们的重视。为了有计划地利用枝丫资源,进一步开展木材综合利用,我们最近到黑龙江、吉林和大兴安岭林区,对枝丫数量、枝丫材(指3厘米以上大枝丫,包括遗弃材等伐区剩余物)生产和利用情况进行调查。现将有关资料、进行简要整理。     

试论伐区枝丫生产工艺

如何生产枝丫,目前尚未形成定型的工艺。根据东北地区伐区枝丫生产利用情况,可把枝丫生产分为两种形式。1.山上枝丫削片。即利用移动式削片机在山场或装车场,把枝丫削成木片后运出。因它是以木片形式运输。效率较高,成本低,易实现装卸机械化,减少人力消耗,削片机能深入伐区,资源充足,减少被丫集装过程。缺点是提高削片机性能难度大,木片质量不易保     

竹柳枝丫材与小径材中密度纤维板的研究

以竹柳枝丫材和3年生小径材为原料,采用脲醛树脂胶分别制备中密度纤维板。对比分析枝丫材与3年生小径材的密度、化学成分、纤维得浆率和纤维形态,研究施胶量和板材密度对竹柳纤维板物理力学性能的影响。结果表明:竹柳枝丫材的密度小于小径材的密度;竹柳枝丫材与小径材均有较高的综纤维素含量;竹柳枝丫材的纤维得浆率低于竹柳小径材;竹柳枝丫材、小径材纤维的壁腔比均小于1,是良好的纤维原料;竹柳枝丫材与小径材所制板材的性能均随着密度和施胶量的增加而明显提高;竹柳枝丫材所制纤维板的性能略低于小径材的,竹柳枝丫材所制纤维板在密度为0.75g/cm~3,施胶量为14%时,其物理力学性能可满足GB/T 11718—2009的要求;而竹柳小径材所制纤维板在密度为0.70g/cm~3,施胶量为14%时即可达到国标要求。     

切花月季的温室生产

选用2年生切花月季红色系品种萨蔓莎作试材，探讨其温室栽培中所留主枝多少与切花产量、质量的关系。试验结果表明：选留4条主枝的植株比选留6条、8条主枝的植株，切花产量高、质量好。选留主枝数量与各生长阶段所需时间长短无关。     

Estimating the equilibrium position by measuring growth stress in weeping branches ofPrunus spachiana Kitamura f.spachiana cv.Plenarosea

The equilibrium position of a current-year branch of the weeping Japanese cherry,Prunus spachiana Kitamura f.spachiana cv.Plenarosea, was estimated by measuring the released strains of growth stresses. In current-year branches that were supported with wires to prevent weeping as soon as the branches first budded, tensile growth stresses on the upper side were smaller than those of the control branches. Gelatinous fibers were rarely found on the upper part of the cross section of the supported branches, whereas the control branches had many gelatinous fibers on the upper part. The upright orientation of the supported branches was closer to the equilibrium position than the weeping orientation of the control branches. The equilibrium position of the branches was thought to be in the initial bud direction, above the horizontal plane; and the weeping style of branch was not the preferred angular orientation forP. spachiana.     

水曲柳珍稀树种扦插繁殖技术的研究

在全光下应用双长臂旋转扫描喷雾装置进行水曲柳(Fraxinusmandshurica)扦插试验,通过对插穗的母树年龄、伐根萌条的枝条部位、切口形状、ABT生根粉配置浓度等指标的研究,结果显示,从10、15年生树冠上剪取1、2、3年生枝条,40年生树冠上剪取2、3年生枝条,40年生伐根上剪取1年生枝条做插穗,对生根率的影响差异达到了极显著水平,按生根率高低排序:伐根当年萌生枝条84.76%>10年树的1年枝条82.5%>15年生树的1年枝条79.68%>10年生树的2年枝条56.21%>15年生树的2年枝条55.63%>10年生树3年枝条52.46%>15年生树3年枝条50.62%>40年生树冠的2年生枝条48.36%>40年生树冠的3年生枝条45.59%,切口形状、ABT生根粉浓度和浸泡插穗基部时间对生根率的影响差异极显著,插穗以斜切口,ABT生根粉浓度用质量分数为2.0×10-4的溶液,浸泡插穗基部根时间以4 h为最佳组合,平均生根率为84.76%,最高为93.14%,伐根萌生枝条部位对生根率的影响差异不显著。     

银杏树冠结构对主干直径和干形的影响

以19年生实生银杏为研究对象,每木检尺,研究了银杏树冠的结构因子一级侧枝的层性、数量和基径对主干直径和干形的影响,主要结果如下:(1)银杏主干上一级侧枝分布的层性和不均衡,导致了主干不同部位生长量分配的差异,表现为随着树冠高度的增加,一级枝数量在树冠垂直方向上呈现“一年小一年大”的波动式变化;一级侧枝层的层间距在0.58~0.82m之间;某层侧枝数量少时,该层上方的层间距较大,反之亦然。(2)树冠上不同层次的一级侧枝及其数量和基径的差异引起主干直径与材积的不均匀分布,导致树干形质发生变化,表现为一级侧枝的基径随着树冠的高度增加呈现“升高-降低”的变化趋势,且树冠中部的一级侧枝的基径较大;每一轮的侧枝使该层侧枝上部的主干不同程度地变细。随着一级侧枝层的上移,侧枝层使胸高形率呈现缩小的变化趋势。一级侧枝直径生长影响着主干上下部直径增量的分配。     

广州河涌水际景观规划设计对策

广州城市河涌水际空间景观功能和形式单一。本文基于景观设计和生态理念两个层面，探讨了城市河涌整体形象规划、河涌水际景观空间结构处理、河涌水域生态性景观恢复对策等问题，以期为广州市内河涌综合整治提供参考。     

Relation between length and diameter of Pinus radiata branches

Abstract

The purpose of this study was to construct a model for the architecture of branches in Pinus radiata D. Don and to use it as a part of a modelling effort to relate timber quality as a function of growth and development. Diameter of branches at the insertion point and their length were measured from two types of branches on 2127 normal, healthy and growing branches of different ages, on 15-year-old radiata pine growing in a good and medium productive site in Chile, in stands that either were left without management or had been thinned and pruned. Statistical analysis showed a simple linear relationship between length and diameter with a common proportionality coefficient (slope) in both types of branches, different sites and management regimens. The equation for order 2 branches differed from that of order 3 branches only in the intercept. The results suggest that the uniform linear relationship between branch length and branch diameter could be applied to radiata pine stands of different site fertility and management regimens.     

Variation in foliar delta(13)C values within the crowns of Pinus radiata trees

Although herbaceous species generally show little within plant variation in delta(13)C, trees show large spatial and temporal differences. We found that the aspect of exposure and branch length accounted for up to 6 per thousand delta(13)C difference within the foliage of individual trees of Pinus radiata D. Don. The foliage on branches 0.5 m in length was as much as 4 per thousand more depleted in (13)C than foliage on 10-m long branches, and an additional 2 per thousand more depleted on the shaded side than on the exposed side. We confirmed that on clear days, relative branch hydraulic conductivity, defined as the ratio of transpiration to the water potential gradient, was much higher in short branches than in long branches. Stomatal conductance remained high in foliage on short branches during the day, whereas it declined progressively in long-branch foliage under similar conditions. These differences were sufficient to explain the observed variation in delta(13)C in foliage on long and short branches.     

Branch and foliage morphological plasticity in old-growth Thuja plicata

At the Wind River Canopy Crane Facility in southeastern Washington State, USA, we examined phenotypic variation between upper- and lower-canopy branches of old-growth Thuja plicata J. Donn ex D. Don (western red cedar). Lower-canopy branches were longer, sprouted fewer daughter branches per unit stem length and were more horizontal than upper-canopy branches. Thuja plicata holds its foliage in fronds, and these had less projected area per unit mass, measured by specific frond area, and less overlap, measured by silhouette to projected area ratio (SPARmax), in the lower canopy than in the upper canopy. The value of SPARmax, used as an indicator of sun and shade foliage in needle-bearing species, did not differ greatly between upper- and lower-canopy branches. We suggest that branching patterns, as well as frond structure, are important components of morphological plasticity in T. plicata. Our results imply that branches of old-growth T. plicata trees have a guerilla growth pattern, responding to changes in solar irradiance in a localized manner.     

Mechanical and ecophysiological significance of the form of a young Acer rufinerve tree: vertical gradient in branch mechanical properties

Most tree biomechanics models assume uniformity of mechanical properties within a tree, and only a few studies have focused on differences in mechanical status among branches. We examined mechanical properties of 49 branches of two 10-year-old trees of Acer rufinerve Sieb. et Zucc. For each branch, bending moment due to its own fresh mass, elastic modulus, section modulus and flexural stiffness were obtained. Elastic modulus of the branch was correlated with the density and thickness of the fiber cell wall and decreased with crown depth, indicating that branches at lower positions were more elastic than branches at upper positions. Compared to lower branches, upper branches were less inclined, possessed thicker growth rings, more long shoots and were subject to smaller stresses. The leaf arrangement in the upper branches might be effective in transmitting more light to the lower branches. In contrast, the lower branches were more inclined toward the horizontal and subject to greater stresses than the upper branches. Lower branch inclinations were attributed to smaller dry matter investment in diameter growth. Upper and lower branch inclinations were slightly greater and smaller, respectively, than those predicted by beam theory. The alleviation in inclination of the lower branches is probably caused by negative gravitropic responses such as tension wood formation or upward shoot elongation, or both. The horizontal display of leaves in the lower branches would be effective in light interception. The reduction in cost of the lower branches can be adaptive because they have a shorter life expectancy than the upper branches. The results showed that an adaptive tree form is realized by a vertical gradient in branch mechanical properties.     

Effects of eucalypt residue management on nutrient leaching and soil properties

Effects of harvest residues on nutrient leaching and soil chemical properties were studied in a lysimeter experiment. Treatments were: (A) forest floor litter and harvest residues, other than branches, incorporated into the soil, (B) as A, but with branches cut in 20 cm long bits and placed on the soil surface, (C) as B, but with bits incorporated into the soil, (D) as B, but with branches chopped into chips, (E) as C, but with branches chopped into chips, (F) forest floor litter and harvest residues on the soil surface, with branches cut in 20 cm long bits, (G) as F, but with branches chopped into chips, and (H) absence of harvest residues (control). Treatments were applied in zero-tension lysimeters containing 25 kg of soil. Leachates were collected for a 6-year period. At the end of the experiment, lysimeters were dismantled and soil was divided in four layers. Residues, other than branches, increased N leaching, as compared with the control. Branches on the soil surface reduced N leaching when cut in chips. Branches incorporated into the soil reduced leaching independently of their size. Organic residues on the soil surface showed similar effect to those incorporated into the soil. However, harvest residues on the soil surface increased leachate volume, and reduced Ca and P losses. Such a placement of residues led to high contents of Ca and P in the 0–5 cm top soil layer. Contents of organic C, total N and base cations were not affected by the treatments.