油松心边材量及年轮数的变异特征

Variations in Amount and Ring Number of Sapwood and Heartwood of Pinus tabulaeformis

在太行山石灰岩区4个林龄与密度不同的油松人工林内选取40株样木,用联苯胺染色法对其上截取的350个圆盘的心、边材进行区分。在此基础上,对心、边材量及年轮数的变异进行分析。结果表明:树干4个方位的心、边材量无显著差异性(P>0.05);边材宽度在距基部0.50～1.00m以上到距树梢2.46～3.22m以下相对恒定,而心材半径、心材面积与边材宽度随树高增加持续减小,横截面直径较好地解释了心、边材量的轴向变异;心、边材量的株间变异很大,胸径对此变异的解释能力高于其他树木变量;4个林分的心、边材量存在显著差异性(P<0.05),林分尺度的心、边材量与林分生长水平及林龄的变化趋势一致;油松心材的起始形成层年龄为13年,心材年轮数随形成层年龄而增加,后者可解释前者变异的97.9%;形成层年龄为40年与60年时,心材年轮数的增长率分别为0.5年轮.a-1与0.7年轮.a-1。研究认为用林分调查因子预测油松心、边材量及心材年轮数的变异是可行的。

Variations in amount and ring number of sapwood and heartwood were analyzed by using 350 benzidine-stained wood disks from 40 sampled trees of four Pinus tabulaeformis stands in limestone area of Taihang Mountain,varying in age and density.At the within tree level heartwood radius and sapwood width have no significant difference among four stem orientations（P0.05）.Sapwood width remained relatively constant along the tree stems from 0.50～1.00 m above the stem bases to 2.46～3.22 m below treetops,heartwood radius,heartwood area and sapwood area decreased with tree height,their longitudinal variations were well explained by stem cross-section diameter.At the individual tree level sapwood and heartwood amount varied greatly,and correlated best to DBH among selected tree variables.At the stand level sapwood and heartwood amount had significant difference（P0.05）,their variation patterns were same as the stand age and stand growth level.The heartwood initiation cambial age was 13 years,number of heartwood rings increased with cambial age,the latter can account for 97.9% of variation of the former.Heartwood formation expressed as the number of new heartwood rings formed each year was found to increase from 0.5 rings per year at a cambial age of 40 years to 0.7 rings per year at a cambial age of 60 years.These results imply that it seems feasible to predict sapwood and heartwood amount and heartwood ring number by using inventory factors.