【作者】 王燕高；

【导师】 胡庭兴；

【作者基本信息】 四川农业大学 ， 森林经理学， 2005， 硕士

【摘要】 本文对从澳大利亚引种到四川栽培的巨桉人工林,按GB1927～1942—91《木材物理力学性质试验方法》的规定,进行了木材物理力学性质研究。研究的木材物理性质有木材的密度、含水率、干缩性、湿胀性、吸水性;研究的木材力学性质为顺纹抗压强度、抗弯强度、抗弯弹性模量、顺纹抗剪强度、抗劈力、冲击韧性和硬度。所采集的巨桉样木来自富顺县、丹棱县、夹江县和犍为县,分别代表四种不同的培育措施,共采9株。研究了不同培育措施对巨桉木材性质的影响,并对改善巨桉人工林材性的经营措施进行了探讨,主要研究结果如下: 1.巨桉人工林木材气干密度在0.437～0.580g/cm~3间,其中间伐后的11.8a生富顺材气干密度为0.580g/cm~3,属中等范围,表明树龄大的间伐材气干密度也大;犍为材气干密度为0.498g/cm~3,属于小的范围;仅施底肥的丹棱材与施肥的夹江材气干密度各为0.514g/cm~3、0.437g/cm~3,也属于小的范围,施肥可能降低木材气干密度。 2.木材基本密度在0.394～0.528g/cm~3间,单纯施肥不能增加巨桉木材的基本密度。四川6a生巨桉人工林的基本密度同国外8a生巨桉人工林基本密度相当,说明四川巨桉人工林综合材性指标较好,有较好的发展前景。 3.间伐后的11.8a生富顺材的顺纹抗压强度、抗弯强度、抗弯弹性模量、顺纹抗剪强度、冲击韧性、抗劈力、硬度皆比未间伐的5.5a生犍为材高,差异相对值在3.55%～31.63%间。适当的间伐不会降低木材物理力学性质,还可加快树木生长。因此,在制定林木定向培育计划时,对于建筑、家具和胶合板材,可采用间伐促进树木生长,使其材性满足加工利用的要求。 4.施肥的夹江材顺纹抗压强度、抗弯强度、抗弯弹性模量、顺纹抗剪强度、冲击韧性、硬度都比未施肥的犍为材低,但抗劈力比犍为材高。木材体积干缩率比犍为材低,可提高木材尺寸的稳定性。说明施肥虽会降低木材的一些物理力学性质,但可使木材某些材性指标得到改善。旌肥能使树木生长加快,树高、胸径和材积均比未施肥的高,其材性指标仍能满足生产纸浆材、家具材等的要求。 5.施底肥的7.7a生丹棱材与未施肥的5.5a生犍为材相比基本密度高13.58%,并且施底肥能降低木材干缩率。施过底肥的7.7a生丹棱材抗弯强度、径面顺纹抗剪强度、抗劈力、硬度和冲击韧性比未施肥的5.5a生犍为材高,说明树龄大且施更多还原

【Abstract】 Based on the GB1927—1942—91 standard of 《Experimentation Methods of Wood’ s physical mechanical property》 , this paper studied the methods of wood’s physical mechanical property for the plantation of the Eucalyptus grandis in Sichuan which introduced from Australia, and the study of physical property includes woods density, hydrous rate , shrinkage rate, wet swelling, absorbs water rate. Researches of mechanical property include compressive strength parallel to grain, bending strength, modelus of elasticity in bending strength, shearing strength parallel to grain, felling shake, toughness and hardness. All the 9 samples come from Fu-shun County, Dan-ling County, Jia-jiang County, and Qian-wei County, which represent four different cultivation measures respectively. This paper studied the affection of different silvicultural measures to the Eucalyptus grandis wood property, and discussed the management measures to improve the wood property of the Eucalyptus grandis. The main research results are as follows:1. The plantation of the Eucalyptus grandis average wood air-dried denisty is between 0. 437 and 0. 580g/cm~3, and among these woods, the woods (11.8 years) come from Fu-shun County with thinning measures with the air-dried denisty of 0.580g/cm~3, belong to medium range, indicate that the older the tree with thinning measures is, the bigger the wood’ s air-dried denisty is. The woods come from Qian-wei County with the air-dried denisty of 0.498g/cm~3, belong to lower range; The woods come from Dan-ling County only with apply fertilizer to the subsoil measures and woods comes Jia-jiang County with apply fertilizer measures have different air-dried denisty, respectively 0.541g/cm~3 and 0.437g/cm~3, which shows that fertilization may decrease the wood’ s air-dried denisty.2. Wood’ s basic denisty is between 0. 394 and 0. 528g/cm~3, single apply fertilization measures can’t increase the wood’s basic denisty of the Eucalyptus grandis. The plantation Eucalyptus grandis (6 years) in Sichuan has nearly the same wood basic denisty compared with the plantation of Eucalyptus grandis abroad, which indicate that it has a better wood property, and will also get a better development.3. The woods come from Fu-shun County (11.8 years) with thinning measures have higher property in those indexes such as compressive strength parallel to grain, bending strength, modelus of elasticity in bending strength, shearing strength parallel to grain, felling shake, toughness and hardness, and the relative difference is between 3. 55~ 31.63%. Proper thinning won’t decrease the physical mechanical property of the wood, on the contrary, it will fasten the growth of trees. So, when we are making our silvicultural plans, for construction, furniture and veneer use, we can adopt thinning measures to fasten the growth of trees to meet the requires of utilization.4. The woods come from Jia-jiang County with apply fertilizer measures have lower property than those woods come from Qian-wei County without apply fertilizer measures in those indexes such as compressive strength parallel to grain, bending strength, modelus of elasticity in bending strength, shearing strength parallel to grain, toughness and hardness, but have higher property in felling shake. Shrinkage rate of the wood volume is lower than those in Qian-wei, which can improve the stability of wood dimension. This means that apply fertilizer may decrease some physical mechanical property of wood, but at the same time it can improve the other wood property indexes. Fertilization measures can fasten the growth of trees, improve the height, chest high diameter and volume, and the wood quality can also meet the requires such as pulpwood and furniture wood production.5. Comparing the woods come from Dan-ling County (7. 7years) with apply fertilizer to the subsoil measures with the woods come from Qian-wei County (5. 5years) without apply fertilizer measures, the former’s basic denisty increased by 13. 58%. Apply fertilizer to the subsoil could reduce the shrinkage of woods and improve those indexes such as the bending strength, shearing strength parallel to grain of radial section, felling shake , toughness and hardness, which indicate that the older tree with apply fertilizer to the subsoil measures have higher physical mechanical property in many indexes.6. Based on the analysis of how different cultivation measures influence the property variation rules of woods, this paper constructed an optimal silvicultural model of the plantation of the Eucalyptus grandis that used for industry fiber and big dimension woods purpose, which can also guide the purposeful cultivation and utilization in some extent.7. Management measures which can improve the property of the plantation of the Eucalyptus grandis includes: appropriate site conditions, fitting planting density, proper thinning and circulation period, fertilization and pruning.更多还原