自动调控树高曲线和一元立木材积模型*

吉林延边地区目前年用一元立木材积表的误差，主要来源于估计各径阶高的误差。本文以双曲线为例，介绍三种多元树高曲线模型；称为自动调控树高曲线。在测定小班（或样地）直径分布时，同时测定小班（或样地）的断面积平均高，由此计算树高曲线，进而得到相应的一元立木材积表。其首选自动调控树高曲线式：Ｈ＝Ｈｍ．Ｄ／［Ｄ＋（Ｈｍ／Ｈｇ－１）Ｄｇ］。此式导出的一元材积表，经验证与实测材积的误差比原地区一元材积表减少约５０

Self-adjusted Height-Diameter Curves and One-entry Volume Model

It is proved that the error of one-entry volume tables presently used in Yanbian District,Jilin Province mainly comes from the estimate error of the average heights in diameter classes. Three types of multi-entries height-diameter model,named self-adjusted height-diameter curves,are introduced in this paper. The mean height of basal area are measured while the diameter distribution is measured for one subcompartment(or plot). Height-diameter curve will be estimated from the mean height and diameter distribution,and then an one-entry volume model will be obtained. The results of the research show that the first choice of the type of height-diameter curves is the reduced hyperbolic type,H=H_m·D/[D+(H_m/H_g-1)D_g](1) where D-diameter of a tree,H-its estimated height,H_g-mean height of basal area,D_g-basal area average diameter,H_m-height limitation(parameter).The self-adjusted one-entry volume models corresponding to equation(1)are developed. The results show that the error of self-adjusted one-entry models is 50% less than that of the present one-entry volume tables used in Yanbian District.