落叶松人工林节子不同生长阶段年轮数量的研究

Knots’ Rings in Different Development Phases for Larch Plantations

以不同年龄、密度和立地条件下的落叶松人工林为研究对象,基于19块标准地中95株标准木所得的节子剖析数据,分析了节子在不同阶段的生长变化规律。研究结果表明:落叶松人工林节子在正常生长阶段产生的可见年轮数为1～36个(平均为10.9个),节子可见年轮数与节子寿命和节子着生高度成正比。落叶松人工林节子丢失年轮是普遍现象,丢失年轮的个数为0～19(平均为3.44),节子丢失年轮数与节子寿命成正相关。在此期间枝条对树木生长没有贡献,可以作为人工整枝的开始时间。节子从死亡到被包藏的时间平均为12年,大约占枝条总生长时间的51%,此段时间产生的疏松节对木材材质影响较大。

Based on the knot analysis data of 95 sample trees in 19 sample plots, the number of rings of knots in different development phases was analyzed for larch（Larix gmelinii） plantations with different ages, stand densities and sites. The results showed： The knots of larch plantation produced perceptible rings during normal growth. The number of perceptible rings ranged from 1 to 36, with an average of 10.9. The relationship between perceptible rings and length of knots was positive linear. It is common that the knots of larch plantation had missing rings, the number of missing rings was from 0 to 19（mean value is 3.44）. The missing rings increased with knots length increasing. During this period the branches made no contribution to the growth of trees, so this was the right time for artificial pruning. The time of knots between death and occlusion was 12 years on average, which was about 51% of their total growth time. The loose knots produced during this period would be a great impact on the quality of wood.