【作者】 王石磊；

【导师】 王庆成；

【作者基本信息】 东北林业大学 ， 森林培育， 2010， 硕士

【摘要】 本文通过研究不同立地、不同林分密度和混交状况下自然生长的白桦(Betula platyphylla)的生长、木材材性、木材化学成分的变异规律,系统的分析了白桦作为纸浆用材的适宜培育方式,研究结果表明：1.不同立地类型(坡位、平地、草甸)中,白桦在中坡位的生长状况最好,其平均树高(16.63 m)、胸径(15.17 cm)及年轮宽度(2.80 mm)分别高于上坡位[3.31%、5.81%、12.60%(p<0.05)]、草甸[25.69%(p<0.05)、28.53%(p<0.05)、16.77% (p<0.05)]。2.立地类型对白桦木材基本密度、纤维长、长宽比影响差异显著(p<0.05)。上坡位木材基本密度(0.513 g／cm3)高于平地(0.466 g／cm3)与草甸(0.453 g／cm3)10.09%、13.25%,下坡位白桦木材纤维长(1.168 mm)和长宽比(55.15)最大,中坡位白桦木材各化学成分含量最有利于造纸,其综纤维素含量(83.36%)与浆得率(51.18%)最高。3.不同林分密度(1650株／hm2、825株／hm2、500株／hm2)的白桦中龄林中,白桦的平均胸径和年轮宽度差异显著(p<0.05),树高差异不显著(p>0.05)。低林分密度(500株／hm2)白桦平均胸径(12.53 cm)和平均年轮宽度(2.96 mm)最大。4.高密度林分(1650株／hm2)中白桦木材材性最有利于造纸。其木材基本密度(0.523 g／cm3)、纤维长(1.183 mm)和宽(21.7μm)最大,综纤维素含量(83.05%)及浆得率(52.77%)最高,苯醇抽出物含量最低(2.15%),木材各化学成分含量对造纸最有利。5.白桦落叶松混交林中白桦在湿生立地上生长性状较差,在中生立地上较好且优于白桦纯林。中生立地白桦落叶松混交林中白桦平均树高(13.87 m)、胸径(12.33 cm)、年轮宽度(2.65 mm)均高于同立地白桦纯林(13.23 m、11.7 cm、2.49 mm),差异均不显著(p>0.05)。6.中生立地与湿生立地上白桦落叶松混交对白桦木材材性均无显著影响(p>0.05),且同种立地上,白桦落叶松混交林的白桦木材化学成分的隶属函数值低于白桦纯林,故白桦落叶松混交对白桦的材质材性无显著促进作用。通过以上研究,立地类型为中坡位,高密度林分(1650株／hm2)下最适宜培育白桦纸浆用材林。其白桦生长状况较好,木材基本密度较大,木材的纤维性状和化学成分含量最有利于造纸。更多还原

【Abstract】 The effects of site conditions, stand density and mixed conditions on variation of growth, wood property and wood chemical component of Betula platyphylla naturally growing was studied in this paper. The proper method of cultivation birch as pulp timber was systematically analyzed and the results are as follows:1. In different sites (slope positions, flat land, meadow), birches on downhill had the best growth, their average height(16.63 m), DBH(15.17 cm) and ring width(2.80 mm) higher than those of uphill[3.31%,5.81%,12.60%(p<0.05)] and meadow[25.69%(p<0.05),28.53% (p<0.05),16.77%(p<0.05)].2. Impact of sites on wood basic density, fiber length and ratio of fiber length to width of birch show significant differences(p<0.05). Wood basic density on uphill higher than that of flat land(0.466 g/cm3) and meadow(0.453 g/cm3) with rate 10.09% and 13.25%. Fiber length of birch on downhill had the maximum fiber length(1.168 mm) and ratio of fiber length to width(55.15). The wood chemical compositions of birch on middle slope suitable for papermaking. The contents of holocellulose(83.36%) and pulp yield(51.18%) of birch on middle slope had maximum values.3. There are three different stand densities including 1650 strain/hm2,825 strain/hm2 and 500 strain/hm2. The average DBH and ring width of birch had the significant values (p<0.05) and the height had no significant differences among the three stand densities(p>0.05). The average DBH(12.53 cm) and ring width(2.96 mm) of stands with low density(500 strain/hm2) had maximum values.4. The stands with high density(1650 strain/hm2) is favorable to papermaking. The average wood basic density(0.523 g/cm3), fiber length(1.183 mm),fiber width(21.7μm), content of holocellulose(83.05%), pulp yield(52.77%) of birch had maximum values and the content of benzene-ethanol extractive(2.15%) had the minimum value. The wood chemical compositions of birch is favorable to papermaking.5. Birches in the birch and mixed larch forests had a poor growth in water-wet site and had a better growth in the other sites. In the same site. The average height(13.87 m), DBH(12.33 cm) and ring width(2.65 mm) respectively higher than those of pure birth(13.23 m,11.7 cm,2.49 mm). The differences was no significant(p>0.05).6. Effect of water-wet site and other site on wood properties of birches were no significant differences(p>0.05). In the same sit, mean and subordinate function value of chemical composition of birch in larch-birch forest was lower than those in birch pure forest. So the wood property of birch in larch-birch forest had no significantly improvement. The studies show that the birch with the stand density of 1650 strain/hm2 in a middle-aged plantation on middle slope is favorable to papermaking. The birches with a better growth and higher wood basic density which of the fiber traits and the wood chemical compositions was favorable to papermaking.更多还原