摘要
[目的]针对杉木人工林生产力和木材质量降低的问题,开展修枝试验,分析修枝强度对林分生长和无节材形成的影响,以期为杉木无节材培育提供理论依据。[方法]以8年生杉木人工林为研究对象,进行轻度修枝(保留冠长的75%,LP)、重度修枝(保留冠长的50%,HP)和对照(未修枝,CK)3种强度修枝处理,10年后比较不同强度修枝下杉木胸径、树高、材积、木材物理性质的差异,利用旋切法测量节子数量与大小,探讨修枝对林分生长和无节材形成的影响。[结果]不同强度修枝对杉木胸径、树高、材积和饱满度均没有显著影响,也未影响杉木活枝的枝下高和活枝数量。修枝节的直径、长度和体积均显著低于自疏节,修枝处理也显著降低自疏节的数量。轻度修枝和重度修枝分别使单株节子总直径显著降低27.6%和40.8%,使单株节子总长度显著降低26.4%和32.6%,使单株节子总体积显著降低27.8%和45.0%。与有节部分相比,无节木材的密度显著降低,抗压强度和抗弯强度显著增加。[结论]对杉木人工林宜采用修枝措施,在保持林分生长和材积不降低的前提下,减少节子的数量和体积,以提升杉木外观等级并促进杉木无节材的形成。
[Objective]In order to improve the productivity and timber quality of Chinese fir(Cunninghamia lanceolata),a pruning experiment was carried out in a Chinese fir plantation.The impacts of pruning in-tensity on stem growth and knot free timber production were analyzed,which aims to provide guidance for cultivation of knot free timber.[Method]In this study,we performed different pruning intensities in 8-year-old Chinese fir plantation,including light intensity pruning(retaining 75%of crown height,LP),heavy in-tensity pruning(retaining 50%of crown height,HP)and the control(unpruned,CK).The quantity and size of knots were measured by rotary cutting method.The differences of DBH,height,volume and the quant-ity or size of knot among different treatments were compared after 10 years of pruning.[Results]Results showed that pruning had no significant effect on DBH,tree height,volume,plumpness,height of the first living branch and quantity of living branches of Chinese fir.Pruning substantially decreased the quantity of knot of self-pruning,so the diameter,length and volume of knot after pruning were lower than self-pruning knots.LP and HP remarkably reduced total diameter of knot per tree by 27.6%and 40.8%,and total length of knot per tree by 26.4%and 32.6%,and total volume of knot per tree by 27.8%and 45.0%,respectively.Moreover,compared with the knotted wood,the density of knot free timber was significantly decreased,and the compressive strength and bending strength were increased significantly.[Conclusion]It is appro-priate to take pruning measures in Chinese fir silviculture plantations,which can not only effectively re-duce quantity and volume of knot,and improve the appearance grade and knot free timber,but also main-tain the tree growth and stand volume.
作者
王娇
关欣
黄苛
植可翔
陈波翰
段萱
杨佳敏
张伟东
陈龙池
杨庆朋
WANG Jiao;GUAN Xin;HUANG Ke;ZHI Ke-xiang;CHEN Bo-han;DUAN Xuan;YANG Jia-min;ZHANG Wei-dong;CHEN Long-chi;YANG Qing-peng(Key Laboratory of Forest Ecology and Management,Institute of Applied Ecology,Chinese Academy of Sciences,Shenyang 110016,Liaoning,China;College of Resources and Environment,University of Chinese Academy of Sciences,Beijing 101408,China;Huitong National Research Station of Forest Ecosystem,Hunan Key Laboratory for Structure and Ecosystem Service of Subtropical Forest,Huitong 418307,Hunan,China;College of Geographical Sciences,Shanxi Normal University,Taiyuan 030000,Shanxi,China)
出处
《林业科学研究》
CSCD
北大核心
2023年第6期40-47,共8页
Forest Research
基金
“十四五”国家重点研发计划项目(2021YFD2201302,2022YFF1303003)
国家自然科学基金项目(41977092,U22A20612)。
关键词
杉木
修枝
生长
节子
物理力学性质
Cunninghamia lanceolata
pruning
growth
knot
physical and mechanical properties
