广西桉树相对树高曲线模型研建

Study of Relative Tree Height Curve Models for Eucalypt in Guangxi

为运用相对树高曲线模型快速准确测算桉树林分蓄积,以广西桉树为研究对象,基于336块样地调查数据,以相对直径RD_(i)为自变量、相对树高RH_i为因变量拟合得到最优相对树高曲线模型RH_(i)=(1-e^(-0.512 38))^(-0.826 11)×(1-e^(-0.51 238×RDi))^(0.826 11)。经检验,模型总相对误差和平均系统误差均小于2%,平均百分标准误差小于6%,预估精度大于99.7%;通过分树种、分区域和不同林分平均胸径、平均树高分段检验,模型总相对误差和平均系统误差在5%以内,平均百分标准误差均小于10%,预估精度达98.0%以上,表明研建的桉树相对树高曲线模型适应性和通用性良好,为广西桉树森林资源规划设计调查、伐区设计调查、森林资源资产评估提供一种快捷且精确的林分蓄积估算方法。

In order to facilitate the swift and precise calculation of eucalypt forest volumes using relative tree height curve models for use in Guangxi eucalypt plantations,an optimal relative tree height curve model was developed using data gathered from 336 sample plots.The model was generated by fitting relative diameter(RDi)as the independent variable against relative tree height(RHi)as the dependent variable(RH_(i)=(1-e^(-0.512 38))^(-0.826 11)×(1-e^(-0.51 238×RDi))^(0.826 11)).The model underwent validation,with the total relative error and average systematic error both falling below 2%,the mean percent standard error being less than 6%,and the estimation accuracy exceeding 99.7%.Through testing by tree species,region,and different forest stands based on average breast diameter and average tree height segments,the model displayed total relative errors and average systematic errors within 5%,with mean percent standard errors below 10%,and an estimation accuracy exceeding 98.0%.This suggests that the eucalypt relative tree height curve model developed is well-suited and versatile.It offers a rapid and precise method for estimating forest volume in the context of forest resource planning and design surveys,logging area design surveys,and forest resource asset assessments in Guangxi eucalypt forests.