日本花柏人工林生长规律与晚材率、木材密度的变异

本文对日本花柏生长规律、晚材率和木材密度等性状的变异进行分析,并就日本花柏木材资源的利用进行了讨论。日本花柏的树高、胸径随着树龄增加逐渐增大,5～9年为速生期,10年之后生长速度在稳定中略有降低;33年生日本花柏材积一直呈上升趋势,其连年生长量与平均生长量并未相交,材积还未达到数量成熟。日本花柏株内晚材率径向变异范围为11.08%～32.05%,均值为20.59%;林分内株间晚材率均值为18.75%。株内基本密度径向变异范围为0.29～0.36g/cm3,均值为0.32g/cm3,变异系数为5.04%;日本花柏浸提物含量较为稳定,径向变异范围5.87%～8.48%,平均值为7.08%。林分内株间浸提前木材基本密度为0.30～0.35g/cm3,基本密度均值为0.32g/cm3;浸提后基本密度为0.28～0.32g/cm3。其材质类似于杉木。

Growth Regularity of Chamaecyparis pisifera and Variations for Latewood Percentage and Wood Basic Density

An experiment was conducted to study the growth regularity of Chamaecyparis pisifera and variations of latewood percent and wood basic density. Results showed that DBH and tree height of C. pisifera increase gradually with stand age. G. pisifera grows rapidly between five-year-old and nlne-year-old, then its growth increment become stable but with a slight decrease after 10-year-old. Tree volume shows an increasing tendency for 33-year-old C. pisifera stands, and its mean increment does not intersect its current annual increment, which indicates that the volume does not reach quantitative maturity. The variant range of latewood percent is from 11.08% to 32.05% in radial direction within individuals and the mean latewood percentage is 20.59%. The latewood percentage on average is 18.75% in stand between individuals. In radial direction, wood basic density is from 0.29 g/cm^3 at pith to 0.36 g/cm^3 at bark, and the average is 0.32 g/cm^3 and the variant coefficient is 5.04%. The extractives content of hot-water is higher, and its variant range in radial direction is from 5.87% to 8.48% with the average of 7.08%. Mean basic density of unextracted wood for increment-bore samples within a stand is 0.32 g/cm^3 , and the variant range is between 0.30 g/cm^3 and 0.35 g/cm^3. Basic density of extracted wood is from 0.28 g/cm^3 to 0.32 g/cm^3. C. pisifera are similar to Chinese fir in wood properties.