粤北低山丘陵地区小红栲木材物理力学性质初步研究     

李重根  何树火 《广东林业科技》1996,12(3):6-10

对粤北山区速生树种小红栲木材的物理力学性质进行了测试，并据此分析了该木材的加工利用价值，提出了开发利用的途径  相似文献   

Modified algorithm to determine localized modulus of elasticity of lumber     

F. Lam  Prof. Dr. R. O. Foschi  Prof. Dr. J. D. Barrett  Technician Q. Y. He 《Wood Science and Technology》1993,27(2):81-94

Summary A procedure has been developed to determine the cut-off frequency in an algorithm to evaluate the localized modulus of elasticity (MOE) in lumber. MOE profiles have been artificially generated to serve as input for evaluation of the procedure. A noise component has also been added to the input record to test the robustness and accuracy of the procedure. Good agreement between program predictions and the known localized MOE values has been obtained. The efficiency of the procedure has also been tested using MOE profiles collected from experiments. The program performed efficiently and program predictions seemed reasonable.  相似文献   

侧柏种源幼林期生长及适应性状变异的研究     

李书靖  何虎林 《甘肃林业科技》1995,20(1):7-11

对我国侧柏自然分布区范围内２３个种源在甘肃两个试验点１０年的研究结果表明：种源间幼林期的生长量、结实期及适应性存在显著差异；种源与立地有一定的交互作用；种源的高生长与年龄呈极显著正相关；种源的生长量基本趋于由南向北、由东向西，从低海拔到高海拔，生长逐渐〔漫的规律。根据种源生长速度、适应性和形态特征等性状的变异表明：西北部种源适应性强，生长慢，侧枚密生，树形美观，可主要用于荒山造林和城市绿化；东、南部种源生长快，树冠较窄，主干明显，宜营造用材林。  相似文献   

绿秆黄槽白夹竹生物学特性的研究     

何俊  沈承权  樊季旻  傅必逊 《竹子研究汇刊》1995,(2)

绿秆黄槽白夹竹(Phyllostachys nidularia)是天然形成的园艺新品种,1989年以来,对其生长发育特性以及与环境条件的关系进行了研究,揭示了它的“地下茎—笋—幼竹—成竹”的生长规律以及出笋和退笋的特点,为制订科学的培育技术措施提供依据。  相似文献   

美国火炬松优良家系引种试验研究   总被引：6，自引：2，他引：6  

钟伟华  王章平 《广东林业科技》1997,13(2):1-6

从美国引入火炬松种子园自由授粉的３３个优良家系进行引种试验。结果表明：家系间树高，胸径、单株材积生长量差异显著，经ＬＳＤ比较选择，仅有６个家系单株材积生长量优于商品种；家系前－后期树高生长相关性显著；家系的遗传力大于单株的遗传力。结果还显示，引进经人工选择的优良家系，还需经过引种区测试，并注意选择最适种源区，方能用于育种与生产。  相似文献   

蓝桉幼林施肥效应研究   总被引：1，自引：0，他引：1  

何蓉  曾芳群  蒋云东  陈德艾  赵明寿  王萍 《西部林业科学》1997,(3)

在云南省保山市石灰岩红壤地区进行了历时4年的蓝桉幼林N、P、K不同配比的10种处理施肥试验。结果表明，施肥能明显促进蓝桉（Eucalyptusglobulus）幼林的生长；其中处理6、9、10增产效果极显著，树高增加16．31％～20．40％，胸径分别增加18．78％～19．21％，材积增加65．04％～70．19％。有机肥对蓝桉生长有促进作用，施过有机肥的处理10生长始终保持优势；磷肥是蓝桉增产的主要因素，每株施430g钙镁磷肥做底肥能使树高、胸径分别增加14．67％、15．87％，每株施215g钙镁磷肥则树高、胸径分别增加11．44％、7．83％；氮肥各水平间无差异，增产效果不明显；钾肥1、2水平间无差异，3水平可能过量，阻碍了肥效发挥。施肥能提高蓝桉生产的经济效益，较好的几个处理依次为6、9、2、10、3产出投入比值均大于对照。综合以上几个因素，N2P3K2为蓝桉幼林的最佳施肥方案。  相似文献   

Phenological patterns in a southern Amazonian tropical forest: implications for sustainable management     

Robert B. Wallace  R. Lilian E. Painter   《Forest Ecology and Management》2002,160(1-3):19-33

Phenological transects were employed to assess monthly leaf, flower, unripe fruit and ripe fruit abundance for a total of 1732 individual plants within five tropical forest habitats at the ‘Lago Caiman Research Camp’, Noel Kempff Mercado National Park, northeastern Santa Cruz Department, Bolivia. Fruit surveys along trails were conducted concomitantly to assess fruit availability for the resident terrestrial frugivore community. The results of the two methodologies are compared and discussed with respect to wildlife and forest management in the region. Phenological transects revealed that Cerrado forest, tall forest, low vine forest, Sartenejal (swamp) forest, and pied mont (premontane) forest, showed seasonal variations in flower, unripe fruit and ripe fruit abundance, however, the broad temporal patterns were significantly different across habitats. Seasonal variation in overall foliage abundance was only marked for Cerrado forest. Ripe fruit production within the study site was not significantly different across months, with different habitats peaking asynchronously in abundance. From a frugivory perspective, overall ripe fleshy fruit abundance also varied considerably between habitats, and again showed asynchronous peaks in habitat production. However, both methodologies revealed the early dry season (June–July) as a period of ripe fleshy fruit scarcity throughout the study area. This period represents a resource ‘bottleneck’ for the resident frugivore community and phenological results allowed the identification of a number of keystone fruit resources for the region. Furthermore, fruit resources which are super-abundant in the early–mid wet season (November–February) might also be considered keystone resources for the region, given that they are available in an otherwise fruit scarce forest. The dynamic spatial patterning of fruit availability at Lago Caiman suggests that certain habitats might be considered keystone habitats, since they provide the majority of fruit resources on a seasonal basis. Finally, the potential of phenological information in tropical forest management plans is discussed and underlined by the observation that rainfall in itself fails to predict fruit availability in the dominant habitats at Lago Caiman.  相似文献   

Study on dynamics of stem form of Korean pine trees in natural forest stand     

桑卫国  何忠秋  张成钢 《林业研究》1995,6(3):27-29

INTRODUCTIONThcstcmfonl1ofnaturalKorcanpincforcst.ot\ingtothcsupprcsscdandshadcd,isvcry'difTcrcntt`iththatofplantation.Itis\'cry't'aluabIctostud}'thcstcmfonnforn1orcac-knot`lcdgcabouttl1ctrccd)-nan1icsofnaturalKorcanpinc.n1crcl1asbccnconsidcrabIcrescarchontl1cstc111for111cquationsasatoolforforcstmanagcmcnt,butitalmostbasnorclationshipt`-iththcbiologicalgrowthproccss.soitisx'ery'dimcuIttouscthccquationtoanalxrsisthcd\'amicsofstclllform.Hcrcthcdct'clopmcntofstcmformt"ascxPCctcdfornotonI\…  相似文献   

杉木人工林林分直径结构预测影响因子的研究   总被引：8，自引：0，他引：8  

段爱国  何彩云  张建国  童书振 《林业科学》2004,40(5):32-38

林分直径结构预测能为科学地进行人工林的定向培育提供可靠的理论依据。本文从生长方程等 4方面探讨了产生杉木人工林林分直径结构预测效果好坏的原因 ,并对两种参数估计方法作了实证比较研究 ,对影响预测适合度高低的原因从林分因子的角度进行了进一步的探索 ,得到如下实验结果 :不同的回收模型、建模材料、检验材料、生长方程对检验适合度的影响程度分别为具有极显著影响、显著影响、呈显著影响或极显著影响、无显著影响 ,当回收模型采用最简幂函数时 ,适合度均在 5 0 %以上 ,Richards生长方程预测效果较好 ,其 6种情形下的适合度仅有 1种低于 6 0 % ;参数预测法和参数回收法用于预测时检验适合度均较高 ,此 2种方法各有优劣 ,均具有很好的应用前景 ;林分初植密度不同于年龄、立地指数、间伐等因子 ,不同密度范围下的预测适合度大小总体上存在一定的规律 ,且对适合度具有显著影响 ,按密度因子作分类预测时 ,应考虑密度的这种突出效应。  相似文献   

闽南山地桉树纤维材优良无性系的选择研究   总被引：17，自引：0，他引：17  

姚庆端  何水东  张金文  洪长福  李宝福 《林业科学》2003,(Z1)

对福建漳州岩溪、天马 2个试验点 1 3个桉树纤维材无性系的生长性状、木材纤维形态和化学组分等性能进行测定与分析 ,并经多性状综合评判 ,选择出具有较高的生长量、生物量和纤维产量 ,适合闽南山地发展的C9、C1 0、EC1、EC3、C6共 5个纤维材优良无性系 ,其中尤以C9、C1 0、EC1三个无性系的各性状为最优。这 5个无性系 ,3a生年平均树高和胸径生长量、每株干材重量和纤维产量分别可达 3 93～ 6 60m、3 83～ 4 97cm ,9 71～ 2 0 48kg·a- 1 和 4 3 6～ 9 5 2kg·a- 1 ,而且木材纤维形态和化学组成等特性良好 ,可进一步扩大繁殖、推广应用。  相似文献