贵州马尾松单株木二元材种出材率表的编制

Two-dimensional yield-rate tables for merchantable volumes of Pinus massoniana in Guizhou Province

通过模型构建及综合比较,优选出3个方程,构建马尾松Pinus massoniana单株木二元材种出材率表编表模型系统。在此基础上编制了二元材种出材率表,并进行了精度检验。该模型系统的3个模型分别是:①经参数优化后的Kozak削度方程;②基于Kozak方程的累积材积方程:为线性修正后的Kozak积分材积式;③形如山本材积式的树皮材积方程。该模型系统在R软件平台上形成造材程序。结果显示,大、中、小径材的编表平均系统误差分别为-2.87%,-3.35%和-1.35%,由三者共同构成的经济材的编表平均系统误差为0.58%,编表精度满足国家标准(GB/T 20381-2006)的要求,所编制的马尾松单木二元材种出材率表可以在生产上应用和推广。

To construct a model system of two-dimensional,rate-of-yield tables for a merchantable volume of Pinus massoniana wood,three models：（1） a model using Kozak＇s taper function;（2） a log under-bark volume function,obtained by multiplying the integration of Kozak＇s taper function with a constant;and（3）a bark volume function using the same form as Yamamoto＇s volume function were selected.Then bucking was carried out using a cutting program composed by myself in R code.Comparisons of yield-rate tables for two-dimensional merchantable volumes of wood were constructed,and fitting and predicting precision of the tables was tested.Results showed that the average system error for large diameter timber with minimal diameter 26 cm was-2.87%,for medium diameter with minimal diameter 20 cm it was-3.35%,and for small diameter with minimal diameter 6 cm it was-1.35%;meanwhile the error for economic timber consisted of the above three tibmers was 0.58%.This excellent prediction precision of the model system met national standards：GB/T 20381-2006,so these two-dimensional tables of yield rates for merchantable volumes of P.massoniana can be applied and promoted.