【摘要】 基于J L .Harper的构件理论 ,对 1- 2 0a的人工马尾松林苗木的分枝率动态进行了研究 .结果表明 :马尾松树冠上部的分枝率在 1- 12a阶段为逐级上升 ,到 12a时达到最高值 6 2± 1 8974;在 12 - 2 0a之间马尾松的树冠分枝率维持在一个相对较高的水平 ;在树冠的下部 ,分枝率在 11a时达到最大 ,为 2 9± 1 370 3,之后树冠下层分枝率呈逐级下降的趋势 ;马尾松树冠顶层对下层分枝率的抑制作用非常明显 .更多还原

【Abstract】 Based on J.L.Harper′s modular theory,the bifurcation ratios of Pinus massoniana were studied.The results show that in the top of crown,the bifurcation ratio increases with the age from 1 a to 12 a,it comes to maximum at 12 a,then keeps at a comparative high level.But in the lower parts,it comes to maximum at 11 a,then tends to descend.If the leader buds were cut away,the bifurcation ratio of the lower parts would increase greatly.更多还原