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[目的]北美鹅掌楸为优良的珍贵用材树种,研究其生长发育规律及生长性状早晚期相关对于北美鹅掌楸人工林高效培育有重要的指导意义。[方法]本文利用树干解析的方法对江苏句容24年生的北美鹅掌楸人工林生长规律研究,并在此基础上进行胸径、树高和材积性状的年年相关分析以及早期选择效率评价。[结果]研究结果表明:北美鹅掌楸胸径、树高从6 a进入快速生长期,持续到17 a,而材积则在1 10 a增长缓慢,12 a后进入速生期,生长速率在20 a达到最大,22 a后逐渐降低,林分接近数量成熟。生长性状的年年相关及早期选择效率分析结果表明:胸径、树高在6 a与18 a显著相关,材积在6 a与16 a达到显著相关,且此时选择效率最高;若以24 a为伐期年龄早晚相关分析,胸径、材积在16 a与24 a生长量达到显著相关水平,而树高则为14 a。[结论]北美鹅掌楸胸径、树高早期增速较快,进入中壮龄阶段竞争加剧,个体间分化增大。随着林分年龄的增长,研究获得的早期选择年龄也相应地延迟。从加速育种角度,在6 a进行早期选择较为合理,而在培育大径材北美鹅掌楸方面可以16 a之后再进行疏伐选择。
[Objective] The research aimed to study the law of growth and development and the correlation of the early and late growth of Liriodendron tulipifera Linn., An important and precious species of timber tree for the efficient cultivation of Liriodendron tulipifera plantation. [Method] The paper studied the growth regularity of Liriodendron tulipifera Linn., A native of Jurong, Jiangsu Province, based on tree trunk analysis. On the basis of this, annual correlation analysis of DBH, height and volume traits and evaluation of early selection efficiency were conducted. [Result] The results showed that the diameter and height of DBH rose from 6 days to 17 years, while the volume increased slowly at 1 10 years and reached its fast growing stage after 12 years. The growth rate was 20 years Reached the maximum, gradually decreased after 22 a, the number of mature forest near. The annual correlation and early selection efficiency of growth traits showed that the DBH and tree height were significantly correlated with 18 a at 6 a, and the volume was significantly correlated at 6 a and 16 a, with the highest selection efficiency at 24 a The analysis of the age at the beginning and the end of the cutting period showed that the DBH and the volume reached a significant correlation between the growth of 16 a and 24 a, while the tree height was 14 a. [Conclusion] The DBH and tree height of Betula altissima increased rapidly in the early stage, and the competition among the middle-aged and young adults was aggravating and the differentiation between individuals increased. As the stand age increased, the age of early selection of the study was also delayed accordingly. From the perspective of accelerated breeding, it is reasonable to conduct early selection at 6 years, and thinning can be done after 16 years in cultivating large-diameter timber Liriodendron javanica.