30a杉木萌生林和实生林木材的材性比较

以采自湖南省金洞林场同一立地条件、不同海拔高度山地上营造的杉木萌生林和实生林30 a时的木材为研究对象,按照国家标准测定其气干密度、基本密度、顺纹抗拉强度、顺纹抗压强度、抗弯强度、抗弯弹性模量、横纹全部抗压强度(径向、弦向)、横纹局部抗压强度(径向、弦向)等10个指标,并运用Excel、Spss等软件进行数据统计、方差分析。结果表明:萌生林30 a时10个指标的测量均值分别为0.439 g·cm^-3(范围0.398~0.480 g·cm^-3)、0.353 g·cm^-3(范围0.318~0.389 g·cm^-3)、122.79 MPa(范围112.44~133.40 MPa)、51.10 MPa(范围50.09~54.67 MPa)、77.15 MPa(范围74.14~82.84 MPa)、9.16 GPa(范围8.43~9.99 GPa)、2.40 MPa(范围2.13~2.73 MPa)、2.17 MPa(范围2.00~2.30 MPa)、3.68 MPa(范围3.50~3.93 MPa)、3.54 MPa(范围3.17~3.94 MPa);实生林30 a时10个性状的测量均值分别为0.404 g·cm^-3(范围0.380~0.422 g·cm^-3)、0.320 g·cm^-3(范围0.312~0.336 g·cm^-3)、102.21 MPa(范围91.89~118.52 MPa)、46.19 MPa(范围41.52~50.72 MPa)、67.35 MPa(范围61.40~73.62 MPa)、8.05 GPa(范围7.641~8.400 GPa)、2.00 MPa(范围1.70~2.40 MPa)、1.83 MPa(范围1.53~2.03 MPa)、3.38 MPa(范围2.99~3.63 MPa)、3.33 MPa(范围2.90~3.53 MPa)。萌生林与实生林木材的10个指标均存在显著、极显著或极极显著差异。杉木林分的生长状态和木材密度的地理变异有明显的规律性,即生长特性随垂直高度(海拔)增高而减少,但木材密度和木材抵抗外力作用的能力却随垂直高度(海拔)的增高而加大。

Wood Properties Comparison of Cunninghamia lanceolata between Coppice and 30-a Seedling Stand

The physical and mechanical properties of Cunninghamia lanceolata were compared between coppice and 30-a seedling stand.By using Excel and SPSS Statistics,a comparative analysis was conducted on the strategy of air-dry density,basic density,tensile strength parallel to grain,compression strength parallel to grain,bending strength,bending modulus,compression entire strength perpendicular to grain(radial and chordwise),and compression local strength perpendicular to grain(radial and chordwise).Ten properties of the 30-a coppice stand wood were 0.439 g·cm^-3(ranged in 0.398-0.480 g·cm^-3),0.353 g·cm^-3(in 0.318-0.389 g·cm^-3),122.79 MPa(in 112.44-133.40 MPa),51.10 MPa(in 50.09-54.67 MPa),77.15 MPa(in 74.14-82.84 MPa),9.16 GPa(in 8.43-9.99 GPa),2.40 MPa(in 2.13-2.73 MPa),2.17 MPa(in 2.00-2.30 MPa),3.68 MPa(in 3.50-3.93 MPa),and 3.54 MPa(in 3.17-3.94 MPa),respectively.Ten properties of seedling stand wood were 0.404 g·cm^-3(in 0.380-0.422 g·cm^-3),0.320 g·cm^-3(in 0.312-0.336 g·cm^-3),102.21 MPa(in 91.89-118.52 MPa),46.19 MPa(in 41.52-50.72 MPa),67.35 MPa(in 61.40-73.62 MPa),8.05 GPa(in 7.641-8.400 GPa),2.00 MPa(in 1.70-2.40 MPa),1.83 MPa(in 1.53-2.03 MPa),3.38 MPa(in 2.99-3.63 MPa),and 3.33 MPa(range 2.90-3.53 MPa),respectively.The results showed that there was significant difference in these wood properties between coppice and seedling stand.