林业科学2024，Vol.60Issue(6)：50-59,10.DOI:10.11707/j.1001-7488.LYKX20230455
修枝强度对杉木人工林无节材形成及质量的影响
Effects of Pruning Intensity on the Formation and Quality of Clear Wood of Trees in Cunninghamia lanceolata Plantations
摘要
Abstract
[Objective]This study aims to investigate the effects of different pruning intensities on the formation and quality of clear wood of Cunninghamia lanceolata,in order to provide a scientific basis for guiding the cultivation of large-diameter-class,high-quality clear wood of C.lanceolata with reasonable pruning intensity.[Method]With a randomized block design,an experiment was implemented in that a 4-year-old C.lanceolata plantation that was subjected to different pruning intensities(i.e.the trees were pruned annually until their stems with a diameter of 6 cm,8 cm,10 cm,and 12 cm,respectively,and the pruning was stopped when the pruning clear bole height of stems reached 7 m,with the unpruned trees served as the control).After 22 years of pruning,the growth of the trees was investigated.A total of 30 average standard trees from different pruning intensities were selected and cut down,and the stems below 7 m were cut off and carried back to the laboratory for the determination of plumpness of the stems.The number,long diameter,and short diameter of knots were measured after the stems were cut according to the saw-cutting method and rotary cutting method,and the ratios of clear wood volume,knot-free veneer quantity,and knot volume were counted.[Result]The diameter at breast height(DBH)and individual volume showed a significant decrease trend with increasing pruning intensity,but pruning intensity had no significant effect on tree height.The DBH with a pruning intensity of 6 cm was significantly smaller than that with other treatments,and the individual volume was significantly smaller than that with the pruning intensities of 10 cm and 12 cm,and of the control(CK).The DBH with a pruning intensity of 8 cm was significantly smaller than that with pruning intensities of 10 cm and 12 cm,and the individual volume was significantly smaller than that with a pruning intensity of 12 cm.In the 1.3-4 m cut logs,the plumpness with a pruning intensity of 6 cm was significantly higher than that with pruning intensities of 10 cm and 12 cm.In the 4-7 m cut logs,the plumpness with a pruning intensity of 8 cm was significantly higher than that with a pruning intensity of 10 cm.The determination results of the saw-cutting method showed a significant decrease trend of the number of knots with the increasing pruning intensity,and both the long and short diameters of knots decreased with increasing pruning intensity,and the short diameter of knots with a pruning intensity of 6 cm was significantly shorted than that with the other treatments.According to the determination results of the rotary cutting method,the number,long diameter,and short diameter of knots all tended to decrease significantly with the increasing pruning intensity.The ratio of both clear wood volume and the ratio of knot-free veneer quantity tended to significantly increase with increasing pruning intensity,while the ratio of knot volume tended to significantly decrease with increasing pruning intensity.Compared with the control,the ratio of clear wood volume with four pruning intensities were significantly higher(at least 51.1％),and the ratio of knot-free veneer quantity were significantly higher(at least 33.25％).The determination results of both the saw-cutting method and rotary cutting method consistently suggested that with pruning intensities of 6 cm and 8 cm had fewer and smaller distribution of knots,and the ratio of clear wood was more obviously improved.The pruning effect was ranked as pruning intensities of 6 cm＞8 cm＞10 cm＞12 cm＞CK.[Conclusion]The selection of pruning intensity depends on the management objective.If greater DBH,tree height,and individual volume are desired,without demand of wood quality,pruning intensities of 10 cm and 12 cm can be good choice.If higher stem plumpness and ratios of clear wood volume and knot-free veneer quantity,lower ratio of knot volume,fewer number of knots,and smaller long and short diameters of knots are required,without demand of the amount of growth,pruning intensities of 6 cm and 8 cm can be selected.关键词
杉木/修枝强度/无节材/旋切法/锯板法Key words
Cunninghamia lanceolata/pruning intensity/clear wood/rotary cutting method/saw-cutting method分类
农业科技引用本文复制引用
阮颖超,苏比·热西塔洪,林熙,李明,范少辉,冯随起,陈志云,马祥庆,何宗明..修枝强度对杉木人工林无节材形成及质量的影响[J].林业科学,2024,60(6):50-59,10.基金项目
"十四五"国家重点研发计划项目(2021YFD2201302). （2021YFD2201302）
