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对以往树木干形的一系列可变参数削度方程进行比较,根据模型拟合统计量(残差平方和及相关指数),选出其中对落叶松干形拟合效果较好(残差平方和较小、相关指数较高)的模型,并根据模型中可变参数的意义提出了5种描述干形的指数.结果表明:Lee等提出的削度方程的拟合效果较好,可以用来描述落叶松人工林的树干形状;5种描述干形的指数分别为根部梢头削度率、影响点、圆柱体和抛物线体范围值、最小可变参数、最小可变参数所在的相对高度,这些指数可以作为比较干形的方法和工具.较大密度(870株.hm-2)和较小密度林分(275株.hm-2)的林木干形质量都较差,只有适中密度林分(487株.hm-2)的落叶松干形质量较好.
According to the model fitted statistics (squared residuals and correlation exponents), a series of variable parameter taper equations of tree trunk were compared. And smaller, the correlation index is higher), and according to the meaning of the variable parameters in the model, five kinds of indices describing the dryness are proposed. The results show that the fitting effect of the taper equation proposed by Lee et al. Is good and can be used To describe the trunk shape of Larix gmelinii plantations. The five indexes describing dryness are the headstock taper rate, affected point, cylinder and parabola range, minimum and minimum relative parameters, These indexes can be used as a relatively dry method and tool, and the quality of the dry woods of the higher density (870 plants.hm-2) and the lower density forest (275 plants.hm-2) The larch dry mass of the branch (487 plants.hm-2) was better.