摘要
通过对3个树种正形率系列的分析,得出除相对高小于0.03的正形率值突然变大以外,其他97％的值变化规律,从树梢到树干基部呈幂函数型,树干正形率值的变化规律是:距相对高m=0.25(根颈为0)处越近则变动越小。由幂函数和用积分的方法,推导出求任一材种小头直径所对应高度的公式和估计出材率的公式,比较简便和精确地解决了立木材种高度和出材率的计算问题。
Sequential analysis of normal form quotient of PopuLus davidiana Dode. , Abies farge-sii Franch. and Bctula sp. , indicated that the normal form quotient were regular at 97% of the total except that which relative height was less than 0. 03. From the tip to the basal stem the normal form quotient is a type of power function. The regularity of change of the normal form quotient was: the nearer the distance from the relative height = 0. 25 , the smaller the change of normal form quotient. By integration, equation for estimating of corresponding height of top diameter of any assortment and equations for estimating percentage of cut-turn are derived.
出处
《西北林学院学报》
CSCD
1994年第3期53-58,共6页
Journal of Northwest Forestry University
关键词
相对干形
正形率
材种
出材率
relative stem form
normal form quotient
assortment
percentage of cut-turn
