选取小兴安岭地区天然针阔混交林为样地,以红松、冷杉、云杉、水曲柳、枫桦、紫椴等6种主要优势树种为研究对象,分别进行树高和胸径、冠幅和胸径的相关性分析。通过SPSS 20.0软件将调查的数据代入备选的8个经典数学模型中进行回归分析,得到各方程的P值、决定系数R²和相关参数,并采用总误差、平均误差、平均相对误差和均方根误差等验证拟合精度,最终选出最优的树木生长模型。结果表明:针叶树的树高和胸径、冠幅与胸径相关性显著,在树高-胸径模型中平均决定系数为0.809,在冠幅-胸径模型中平均决定系数为0.498。相对于针叶树来说,阔叶树树高和胸径、冠幅和胸径的相关性略差,其决定系数平均值分别为0.608,0.395。不同树种适应不同树木生长模型,在树高-胸径的相关性分析中,以幂函数、S函数模型居多,冠幅-胸径模型以三次多项式模型最为显著。

A natural mixed broadleaf-conifer forest in the Lesser Khingan Mountains was selected as a sample,the main dominant tree species including Pinus koraiensis,Abies fabri,Picea asperata,Fraxinus mandshurica,Betula costata and Tilia amurensis were selected as the research objects,and correlation analysis of tree height vs.DBH,crown width vs. DBH were carried out respectively in this paper.By SPSS 20.0 software,the survey data was substituted into the eight classical mathematical models for regression analysis,the P value,the coefficient of determination R ² and related parameters of each equation were obtained.The fitting accuracy was verified by using the total error,the average error,the average relative error and the root mean square error,the optimum tree growth model was finally selected.The results showed that the correlations between tree height vs.DBH,crown width vs.DBH for conifer trees were significant,and the average coefficients of determination in the tree height vs.DBH model and in the crown,width vs.DBH model were 0.809 and 0.498,respectively.Compared with the coniferous trees,the correlation coefficients between tree height vs.DBH,crown width vs.DBH for broadleaf trees were slightly worse,and the average coefficients of determination were 0.608 and 0.395,respectively.Different tree growth models should be used for different tree species,in the tree height vs.DBH correlation analysis,the power function and S function models were mostly used,while the cubic polynomial model was the most significant among the crown diameter vs.DBH models.