人工兴安落叶松心边材变异及生长特征1）

在黑龙江省林科院丽林实验林场选取了10块落叶松人工林样地，在样地中伐取优势木、平均木和被压木各1株。树木伐倒后，沿着树干以1m区分段截取圆盘，测量其东西和南北2个方向的带皮直径、去皮直径、总年轮数量、边材年轮数量、边材直径。采用正态分布检验、t检验、非参数检验、方差分析、多重比较、相关分析和回归分析等统计方法，研究落叶松心边材的方位变异、株间变异、林分间变异、沿树干方向的变异以及与树木各变量之间的生长关系。研究结果表明：落叶松心边材的方位变异不显著（ P＞0．05）。心边材存在显著的林分间和株间变异（ P＜0．05），胸径较好地解释了心边材的株间变异。心材半径、心材面积和边材面积随着树干的增高而递减，而边材宽度在树干基部较大，1 m以上相保持对恒定，在接近树梢处明显减小。心材半径、心材面积、边材宽度和边材面积与形成层年龄和横截面带去皮直径均存在显著的正相关性（ P＜0．0001）。心边材年轮数随形成层年龄的增加而增加，形成层年龄能够解释90％以上心材年轮数的变化，而仅仅能够解释46％边材年轮数的变化。

Variation of Heartwood and Sapwood and Growth Characteristics of Artificial Dahurian Larch

We selected 10 sample plots of dahurian larch ( Lar ix gmelinii Rupr.) plantations from Lilin Farm in Wuying Forest Bureau in Heilongjiang Province , and three trees with dominant tree , average tree and suppressed trees .Wood discs were cut at intervals of 1 m along the stem of felled tree .We measured the diameter outside and inside bark , overall ring num-ber, sapwood ring number , sapwood width at two directions of northeast and southwest .We studied the variations in heart-wood and sapwood among two orientations , trees and stands , from base to the top of the tree , and growth correlation with individual tree variables using normal distribution test , t test, nonparametric test, variance analysis, multiple comparison, and correlation and regression analysis methods .There were no significant variations among two orientations ( P>0.05 ) . There are significant variations among trees and stands ( P<0.05) and diameter at breast better explained the variations of heartwood and sapwood among trees .Heartwood radius , heartwood area , sapwood area decreased from the stump to top of the tree height for dahurian larch .However , sapwood width was bigger at stem base , remained relatively constant above 1 m to stem, and then decreased at top of the tree .Heartwood radius, heartwood area, sapwood width, and sapwood area had significant correlation with cambial age and outside and inside bark diameter (P<0.0001).Ring number of heartwood and sapwood increased with the increase of cambial age .Cambial age could account for over 90%of the variation of heartwood ring number , only 46%of the variation of sapwood ring number .