共查询到18条相似文献，搜索用时 812 毫秒
1.
观光木的生材性质研究 总被引：3，自引：0，他引：3
对观光木的生材密度、含水率、树皮率及心材率进行测定分析,结果表明:观光木的生材密度从髓心向外呈先减小再增大的趋势,随着树高的增加,亦呈先减小再增大的趋势,其平均值为0.873 g.cm-3;基本密度自髓心向外逐渐增大,随着树高增加,呈先减小后增大再减小的趋势,其平均值为0.423 g.cm-3;含水率从髓心向外呈减小的趋势,随着树高的增加,呈先增大后减小再增大的趋势,其平均值为108.4%;树皮的体积百分率及质量百分率均随着树高的增加而增加,其平均值分别为13.5%、15.8%;心材率随着树高的增加而减少,心材百分率平均值为15.6%。 相似文献
2.
火力楠树皮率、心材率及密度研究 总被引：2，自引：0，他引：2
研究了火力楠的密度、树皮率、生材含水率及心材率,采用排水法测定生材体积,采用体积法及质量法测定树皮率。研究结果表明:火力楠生材密度从髓心向外呈减少的趋势,随着树高的增加,呈减少的趋势,生材密度的平均值为0.976 g/cm3。火力楠的基本密度自髓心向外呈增大趋势,随着树高增加,呈大-小-大-小的趋势,基本密度的平均值为0.546g/cm3。火力楠生材含水率从髓心向外呈减小的趋势,随着树高的增加,呈小-大-小-大的趋势,生材含水率的平均值为85.13%。火力楠树皮体积百分率及质量百分率均随着树高的增加而增加,树皮体积百分率及质量百分率平均值分别为13.80%、14.29%。火力楠的心材率随着树高的增加而减少,心材百分率平均值为35.0%。 相似文献
3.
33年生格木人工林生材性质研究 总被引：1，自引：0，他引：1
《陕西林业科技》2015,(5)
采用体积法和质量法测定树皮率、排水法测定木材体积的方法,研究了33a生格木人工林生材性质,结果表明:树皮体积百分率和树皮质量百分率随着树高的增加而增加,其平均值分别为14.22%和13.29%。心材率随着树高的增加逐渐减小,平均值为16.15%。生材密度从髓心向外,南向和北向生材密度变化规律基本一致,均呈现逐渐减小的趋势,随着树高增加呈现先减小后增大的趋势,平均值为0.893g·cm~(-3)。基本密度从髓心向外,南向无变化,北向则缓慢增加,随着树高增加呈先减小后增大的趋势,平均值为0.559g·cm-3。生材含水率从髓心向外,南向跟北向均呈减少的趋势且南北向数值基本相等,随着树高的增加呈现先增大后减小的变化趋势,平均值为62.15%。 相似文献
4.
香梓楠树皮率、生材含水率及木材密度研究 总被引：1，自引：0，他引：1
采用体积法及质量法测定树皮率,排水法测定生材体积,分析研究香梓楠的树皮率、生材含水率、密度及心材率。研究结果表明:香梓楠树皮体积百分率及质量百分率总体随着树高的增加而增加,树皮体积百分率及质量百分率平均值分别为15.8%和19.8%;生材含水率,从髓心向外,北向和南向均呈减少的趋势,并随树高增加而增加,平均值为99.5%;香梓楠生材密度随树高增加而减小,平均值为0.804g·cm-3;基本密度的径向变化随树龄增加而增大,纵向变化随树高增加而减小,平均值为0.403g·cm-3;11年生香梓楠心材极少。该研究为保护、发展广西重点珍贵树种香梓楠提供了科学依据。 相似文献
5.
对青钩栲(Castanopsis kawakamii)的生材性质进行研究。采用体积法和质量法测定树皮率,排水法测定生材体积,并对测定得到的数据进行分析。研究结果表明:青钩栲树皮体积百分率和树皮质量百分率随着树高的增加逐渐平稳的增加,其平均值分别为11.4%和9.8%。生材密度从髓心向外至中间部分基本没有变化,且南北向数值基本保持一致,但边材部分生材密度较小;沿着树高增加的方向,生材密度呈逐渐减小趋势,平均值为1.170 g/cm3。基本密度自髓心向外先增加后减小,北向的差异比南向的大,但数值上基本都相等;沿着树高增加的方向,基本密度呈先减小后增大再减小的趋势,平均值为0.584 g/cm3。生材含水率自髓心部分向外呈逐渐减小趋势;沿着树高增加的方向,呈先增大后减小再增大的趋势,平均值为95.7%。心材率随着树高的增加呈减小趋势,平均值为22.5%。 相似文献
6.
对柚木木材的生材性质进行研究,可对人工林柚木的合理加工和高效利用提供理论依据。采用体积法和质量法测定11年生的柚木树皮率,用排水法测定木材体积,并用测定得到的数据分析柚木的树皮率、心材率、生材密度、基本密度和生材含水率。研究结果表明：11年生柚木树皮体积分数和树皮质量分数随着树高的增加而增加,在树梢部位树皮率最高,平均值分别为26.26%,25.93%。心材率随着树高的增加而减小,心材在根部较大,树干根部心材率最大为47.63%,平均值为34.60%。生材密度随着树高增加而减小,平均值为1.094 g/cm3,自髓心向外,南向和北向都先减小后增大。基本密度随着树高增加呈现先减小后增加的趋势,平均值为0.558 g/cm3,自髓心向外,南向和北向均逐渐增加。生材含水率随着树高的增加而减小,平均值为97.32%,自髓心向外,南向跟北向均减少且数值基本相等。 相似文献
7.
对降香黄檀（Dalbergia odorifera）的树皮率、心材率，木材密度进行了研究。结果表明：降香黄檀树皮体积百分率及质量百分率平均值分别为20．14％、13．77％；心材百分率平均值为30．53％，心材形成的年龄为9～15a；生材密度平均值为1．064g／cm^3；基本密度平均值为0．715g／cm^3；生材含水率平均值为49．21％。降香黄檀树皮体积百分率及质量百分率均随着树高的增加而增加；生材密度及心材率随着树高的增加而减少；基本密度随着树高增加，呈大-小-大-小的趋势变化；生材含水率随着树高的增加，呈小-大-小-大的趋势变化。 相似文献
8.
《林业实用技术》2015,(11)
对50年生降香黄檀(Dalbergia odorifera)木材的生材性质进行研究,并与25年生降香黄檀进行比较分析。采用体积法和质量法测定树皮率,排水法测定木材体积,并对测定得到的数据进行分析。研究结果表明:50年生降香黄檀树皮体积百分率和树皮质量百分率随着树高的增加而增加,平均值分别为19.81%、19.86%。心材率随着树高的增加而减小,但没有明显的变化规律,心材在根部较大,树干根部心材率最大为30.83%,平均值为7.79%。生材密度从髓心向外,南向和北向都先减小后增大,且随着树高增加而减小,平均值为0.973g/cm3。基本密度从髓心向外,南向和北向均逐渐增加,随着树高增加,呈先减小后增大再减小的趋势,平均值为0.655g/cm3。50年生降香黄檀生材含水率从髓心向外,南向跟北向均减少,随着树高的增加而减小,平均值为48.98%。50年生与25年生降香黄檀相比,心材率均随着树高的增加而减小。两者根部心材率相差不大,但25年生降香黄檀心材率平均值为30.53%,而50年生降香黄檀心材率平均值仅为7.79%,具体原因尚不可知,需进一步探究。 相似文献
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10.
采用体积法和质量法测定树皮率,排水法测定木材体积,研究了红锥5种家系木材的生材性质。研究结果表明,D家系的树皮体积百分率最高,达到10.02%,B、D、P、R、X家系的树皮体积百分率平均值为8.81%。B家系的树皮质量百分率最高,达到13.70%, X家系的树皮体积百分率和树皮质量百分率明显低于其他家系。B、D、P、R、X家系的树皮质量百分率平均值为10.20%;家系间心材率差异不大,平均值为43.79%;家系间南北向生材密度变化规律基本一致,北向从髓心向外均逐渐减小,南向从髓心向外先减少后增大;南北向基本密度数值差异均不大,北向靠髓心、中间及边材等3个位置基本密度平均值分别为0.525、0.583、0.576 g·cm-3,南向靠髓心、中间及边材位置3部分的基本密度平均值分别为0.475、0.500、0.539 g·cm-3;除南向B系列和R系列外,家系间生材含水率南北向变化规律一致,从髓心向外均逐渐减小,中间部分和边材部分差异不大,B系列和R系列的南向从髓心向外先减小后增大,靠近髓心部分的生材含水率明显较高。 相似文献
11.
Alexander Berrocal Johana Gaitan-Alvarez Roger Moya David Fernandez-Solis Edgar Ortiz-Malavassi 《林业研究》2020,31(2):667-676
To elucidate the development of heartwood,bark,sapwood,pith and specific gravity of wood in fastgrowing teak(Tectona grandis)plantations in Costa Rica,we sampled three trees in each of 55 plantations and modelled each variable with age,site and different tree heights.Age and stand density of plantations were significant correlated with stem diameter at breast height and total height of the tree.Formation of heartwood was initiated at the age of 4-year-old and increased in direct proportion with age.The age of plantation had a significant relationship with stem diameter at breast height,heartwood percentage,sapwood thickness,sapwood percentage,percentage of bark,pith diameter and percentage,and specify gravity.The model for these tree parameters was model with these parameters as dependent variable and in relation to age as independent variable. 相似文献
12.
为了解邓恩桉的木材性质,本研究采用排水法和《GB/T 1930-2009》方法测定邓恩桉的生材含水率、年轮宽度以及木材密度。结果表明：全树生材含水率、年轮宽度、生材密度和基本密度均值分别为114.61%、4.73 mm、1.164 g·cm-3、0.522 g·cm-3。随着树高的增加,年轮宽度、木材密度呈-大-小-大‖趋势,生材含水率呈-小-大-小‖趋势;由髓心向外,木材密度逐渐减小,生材含水率逐渐增大,年轮宽度先增加后减小。4个材性指标在树干径向不同位置间差异极显著,在不同树高间差异不显著（除年轮宽度外）。基本密度与3个材性指标间存在极显著或显著相关。 相似文献
13.
Junji Matsumura Yoko Yamasaki Kazuyuki Oda Yoshitake Fujisawa 《Journal of Wood Science》2005,51(4):328-333
Nine trees of Cryptomeria japonica from six elite tree clones with a broad range of heartwood colors were selected. The profiles of pit aspiration percentage (ASP) of earlywood and latewood from pith to bark for green and air-dry conditions were determined to study the relationship between heartwood color and pit aspiration. Confocal laser scanning microscopy (CLSM) observations showed that the ASP of earlywood was low in sapwood and high in heartwood in the green condition. Pit aspiration increased in intermediate wood when compared with sapwood. On the other hand, latewood pits did not aspirate during heartwood formation. Comparing the air-dry condition with the green condition, sapwood pits aspirated during drying in both earlywood and latewood; however, there was no significant difference in pit aspiration of heartwood. There was no significant difference between samples with red and black heartwoods for ASP. The difference in ASP between individual trees was larger than that by heartwood color. The general advantage of CLSM over light microscopy is that serial optical sections along the Z axis can be obtained for any moisture condition, without the need for thin sectioning or embedding. 相似文献
14.
为合理利用异叶南洋杉人工林木材,通过排水法、质量法和数值法对异叶南洋杉人工林的生材性质展开研究,结果表明,异叶南洋杉人工林木材树皮体积百分率、质量百分率、生材密度、基本密度和生材含水率的平均值分别为11.39%、13.78%、0.842 g/cm3、0.394 g/cm3和121.43%。随异叶南洋杉树高的增加,树皮体积百分率和质量百分率总体呈增大趋势;生材密度和基本密度总体呈下降趋势;生材含水率总体呈先升高后降低的趋势。以期为异叶南洋杉人工林木材的合理利用提供数据支持和理论支撑。 相似文献
15.
We evaluated heartwood, sapwood and bark content in teak trees. A total of 27 sample plots were laid out in teak plantations raised by State Forest Department in Karnataka covering different age groups... 相似文献
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Healthy lodgepole pine trees and trees at three stages (green, red and grey) of infestation by mountain pine beetles (MPB)
were examined for moisture and blue-stain distribution in the radial and longitudinal directions. The sapwood moisture content
of trees dropped about 100% from the healthy stage while the heartwood moisture dropped about 10%, regardless of green, red
or grey attack stages. Moisture content variation with tree height was unique up to the time since beetle attack. The volume
of blue stain increased with increasing time since beetle attack. Maximum discolouration in wood occurred at about 3 m above
ground level and expanded rapidly upward. Lumber sawn and tracked from the MPB attacked logs showed a decrease in moisture
content with increasing time since beetle attack, indicating the need for specific drying schedules employing lower energy
levels. The economic implication of the effect of blue stain was evaluated by the percentage of Japanese grade (J-grade) lumber
produced. The J-grade lumber yield decreased with increasing time since beetle attack. Early harvest and conversion of MPB
infected trees will positively impact product value and recovery.
Part of this research was funded by Forestry Innovation Investment Ltd., Government of British Columbia. 相似文献
18.
Indiscriminate use of natural resources in the past has lead to fuelwood shortages in many parts of the tropical world. To surmount this domestic energy crisis, not only degraded sites must be planted with trees having high fuel value potential, but also agroforestry promoted on arable lands. To enable choice of species for such energy plantations/agroforests in the humid tropics of peninsular India, we assessed the heat of combustion and physical properties that determine combustion of phytofuels, such as ash content, specific gravity and moisture content. Bark and wood samples of 45 multipurpose tree species in the homegardens of Kerala, India and three fuel materials of local importance (coconut [Cocos nucifera] endocarp, dried coconut spathe and dehiscent rubber [Hevea braziliensis] pericarp) were evaluated. Variations abound in the calorific values and physical properties of species and tissue-types. In general, heat of combustion and specific gravity followed the sequence: heartwood > sapwood > bark, while mean ash percentage followed a reverse order (bark > sapwood > heartwood). Ash content had a negative correlation with heat of combustion, but specific gravity exerted a positive influence. Furthermore, ash content and wood specific gravity were inversely related. Although green moisture content increased in the order: bark < heartwood < sapwood, it failed to show any predictable relationship with heat of combustion.This revised version was published online in November 2005 with corrections to the Cover Date. 相似文献