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自动调控树高曲线和一元立木材积模型*

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

  • 摘要: 吉林延边地区目前所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%.

     

    Abstract: 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=Hm·D/D+(Hm/Hg-1)Dg(1) where D-diameter of a tree,H-its estimated height,Hg-mean height of basal area,Dg-basal area average diameter,Hm-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.

     

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