威布尔分布模型在巨龙竹林直径与年龄分布特征估测中的应用

Diameter and Age Structure Estimation of Dendrocalamus sinicus Forest with Weibull Distribution Model

以研究区班洪乡处连续分布的整个巨龙竹林分为试验对象、单干巨龙竹为研究单元,于2019年12月份,筛选得到健康且非林缘处生长的巨龙竹共计93丛,对其干高达到主林层及以上的2090干巨龙竹进行直径和年龄检尺统计;应用一元3参数威布尔(Weibull)概率密度函数模型、二元威布尔生存函数模型、2种改进的二元威布尔概率密度函数模型,分析滇西南巨龙竹林直径与年龄分布特征。结果表明:通过概率散点图(P-P)检验法和柯尔莫可洛夫-斯米洛夫(K-S)检验法证实,巨龙竹林直径分布服从威布尔分布,呈单峰状,主要分布于16~20 cm;利用一元3参数威布尔概率密度函数模型拟合其直径分布的效果优良,决定系数R^(2)=0.993 436、平均绝对误差值ε=0.003 183,并得到巨龙竹林直径的一元3参数威布尔概率密度函数最优预估模型;利用二元威布尔生存函数模型拟合巨龙竹林直径与年龄分布的效果优良,R^(2)=0.997 341、ε=64.013 527,并得到巨龙竹林直径与年龄的二元威布尔生存函数最优预估模型和生存株数(概率)预测数表;利用2种改进的二元威布尔概率密度函数模型拟合巨龙竹林直径与年龄分布的效果良好,R^(2)_(1)=0.919 323、ε_(1)=0.000 072、R^(2)_(2)=0.906 260、ε_(2)=0.001 325,并得到巨龙竹林直径与年龄的2种改进二元威布尔概率密度函数最优预估模型和分布概率预测数表。

The diameter and age distribution of Dendrocalamus sinicus forest were fitted and evaluated by using unary 3-parameter probability density Weibull distribution model,bivariate survival Weibull distribution model and 2 kinds of improved bivariate probability density Weibull distribution modes in Southwestern Yunnan,which would provide a reference of D.sinicus forestry management and bivariate Weibull research.The diameter distribution pattern of D.sinicus was conformed to Weibull distribution through the P-P chart and Kolmogorov-Smirnov test,which was single-peak mountain shape and distributed in 16 to 20 cm.The fitted results by unary 3-parameter probability density Weibull distribution model were great(R^(2)=0.993436 andε=0.003183),and its optimal distribution model was solved.The fitted results by bivariate survival Weibull distribution model were great(R^(2)=0.997341 and ε=64.013527),and its optimal distribution model and survival number(probability)table were solved.The fitted results by 2 kinds of improved bivariate probability density Weibull distribution modes were good(R^(2)_(1)=0.919323,ε_(1)=0.000072,R^(2)_(2)=0.906060 and ε_(2)=0.001325),and their optimal distribution models and probability tables were solved.