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以119株河北杨优树组成样本,分别以年平均材积生长量(Y_1)、年平均胸径生长量(Y_2)、年平均树高生长量(Y_3)为因变量,以优树年龄及优树生长等8项气象因子和海拔高度(X_1～X_(10))为自变量建立回归方程。选取Y_1/Y_1、Y_2/Y_2、Y_3/Y_3、树干形率、冠幅/胸径、分枝角度、树干通直度为评判因素,利用模糊综合评判方法,对河北杨优树进行了评比。在此基础上提出了用模糊综合评判法进行河北杨优树选择的方法步骤和标准。
A total of 119 strains of Populus euphratica from Hebei were selected as samples to study the effects of Y1, Y2 and Y_3 on the annual growth, Eight meteorological factors and altitude (X_1 ~ X_ (10)) were used as independent variables to establish regression equation. Y_1 / Y_1, Y_2 / Y_2, Y_3 / Y_3 were selected as the evaluation factors for tree height, crown width / DBH, branch angle and trunk straightness. The fuzzy comprehensive evaluation method was used to evaluate the quality of Yangyou tree. On the basis of this, the method steps and standards for choosing Yangyou tree in Hebei province by fuzzy comprehensive evaluation are put forward.