土贡松树皮率、生材含水率及木材密度研究

Research on Bark Percentage,Moisture Content and Wood Density of Pinus massoniana Lamb

以研究土贡松木材材性为目的,从广西梧州市苍梧县天洪岭林场采集2株试材,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,研究了土贡松的生材密度、树皮率及含水率。结果表明:土贡松生材密度径向变化随树龄增大呈递增趋势;纵向变化则随树高增加变化幅度小,但接近两端处变化显著,平均值为0.900g·cm^(-3)。基本密度径向变化随树龄增加,南向先增加后减少,北向呈持续增加趋势;纵向变化随树高增加,基本密度呈小—大—小变化趋势,平均值为0.457g·cm^(-3)。生材含水率径向变化随树龄增加呈增加趋势,且北向增加趋势较为明显;纵向变化随着树高的增加,在枝下高以下,生材含水率缓慢增大,在枝下高以上,生材含水率显著增大,平均值为99.9%。树皮体积百分率随着树高的增加呈小—大—小—大变化趋势,平均值为9.1%。树皮质量百分率均随树高增高而增加—缓慢减小—突然增大变化趋势,平均值分别为7.0%。该研究为保护、发展广西重点珍贵树种土贡松提供了科学依据。

Pinus massoniana Lamb was selected from Tian Hongling Forestry Farm in Wuzhou of Guangxi. The green wood volume were determined by the drainage method and the bark percentage was determined by the volume method and the quality method so as to calculate the density, bark per- centage and heartwood percentage of the green wood of Pinus massoniana Lamb. The result showed that the green wood density of Pinus massoniana Lamb increased with the tree age. Longitudinal in- crease with tree height was slow, but significant increase near the two ends, with the average value at 0. 900 g ·cm-3. Basic radial density increased with the age, southbound density increasing first and then decreasing while northbound density increasing all the way. Longitudinal density increased with tree height in a trend of small--large--small, with an average at 0. 457g · cm-3. Radial change of moisture content of raw materials increased with the age, northbound increase more significantly. Longitudinal moisture increased with tree height, gradual increase below clear bole height and signifi- cant increase above clear bole height, with the average moisture value at 99.9%. Bark volume per- centage increased with tree height, bark mass percentages increased with tree height in a trend of small--large--small--large, with average value at 9. 1%. Bark quality percentage increased withheight but slowly first and then a sudden big increase, with the average value at 7 %.