金白杨伐桩嫁接林木生物量及材性分析

金白杨是山西省杨树丰产林实验局和山西省林业科学研究院于2013年从银白杨×新疆杨杂交组合中选育的抗逆性和适应性强、速生的优良无性系。笔者以生物量和木材性质为检测指标,对金白杨伐桩嫁接林木的不同器官组织进行剖析研究,结果表明,金白杨伐桩造林6年生林木平均单株生物量鲜重85.45 kg,地下34.6%,地上器官占65.4%,其中,树干45.1%,自生根仅占11.16%,说明林木生物量主要受原有砧木根系的调控;随着树龄增加,从第5年起生物量进入快速增长期;枝叶生物量从4年生起下降,说明金白杨具有侧枝细而树冠窄、主干生物量大、自然整枝好的优点。金白杨木材抗弯强度76.3 MPa,超过新疆杨、小叶杨以及48个杨树树种的平均值;木材抗弯弹性模量比毛白杨小、比新疆杨和小叶杨大,说明木材抗弯性能较好;金白杨木材纤维的长宽比值超过新疆杨、毛白杨和大青杨,且纤维长度均超过1 000μm,综纤维素含量超过毛白杨、小叶杨和大青杨59%以上,所以,其木材是制浆造纸和生产"三板"的优质原料。

Biomass and Wood Property Analysis on Jinbaiyang of Stump Grafting

Jinbaiyang was strong resistance and excellent adaptability clone that was chosen from Populus alba L. × P. alba L. var. pyrarnidalis Bge. by Shanxi Academy of Forestry Sciences and Sangganhe Bureau of Poplar High-yield Forest, Shanxi in 2013. The results showed that a single plant fresh weight of 6a tree of stump forestation was 85.45 kg. Aboveground organs occupied 65.4% , in which trunk occupied 45.1% ; subterranean organs occupied 34. 6%, in which self rooting oceupied 11.16%. It indicated that tree biomass was regulated by original stock root. With the increase of tree age, the biomass turned into rapid growth from the fifth year. Biomass of branches and leaves decreased from the fourth year, that indicated Jinbaiyang had thin lateral branch, narrow crown, bigger truck biomass, good natural training. The bending strength of Jinbaiyang wood was 76. 3 MPa, which exceeded P. alba L. var. pyramidatis Bge. , Populus simonii Carr. and mean value of 48 species. The beding elasticity modulus of Jinbaiyang was smaller thanpopulus tomentosa Carr. , while was bigger than P. alba L. var. pyramidalis Beg. and populus simonil Carr.. The length-width ratio of woody fiber of Jinbaiyang exceeded P. alba L. var. pyramidatis Bge. , Populus tomentosa Carriere and Populus ussuriensis Kom. , and the woody fiber length exceeded 1 000 μm. The total cellulose content exceeded 59% compared with Populus tomentosa Carriere, Populus simonii Carr. and Populus ussuriensis Kom. So, Jinbaiyang wood was the high quality raw materials for pulping and papermaking and producing three board.