大兴安岭兴安落叶松天然林结构特征

以大兴安岭兴安落叶松天然林为研究对象,利用固定样地调查数据,研究其结构特征。结果显示:(1)林分整体的直径分布为倒"J"型,6径阶株数最多,Exp3P2函数可以很好的拟合兴安落叶松的直径分布;(2)林分树高分布为单峰偏左曲线,树高8级时,株数最多,柯列尔函数拟合兴安落叶松树高分布精度高;(3)兴安落叶松树高随胸径增大而增加,可以用Wykoff方程表示其相关性;(4)兴安落叶松的胸径与冠幅为正相关关系,Monomolecular函数拟合结果良好;(5)林分平均角尺度0.485,林分呈现随机分布格局;(6)用胸径、树高和冠幅3个指标计算林分平均大小比数均呈现中庸状态;(7)林分平均混交度0.327,属于弱度混交,表明该地区为典型的兴安落叶松天然林。

Structure Characteristics of Larix gmelinii Natural Forest in Daxing'an Mountains

We studied the structure characteristics of Larix gmelinii natural forest in Daxing' an Mountains with fixed sample plot every wood positioning survey data.The results showed that:①The distribution of diameter is wholly inverted "J" type.The number of tree is most when diameter class is 6.Exp3P2 function can be a good fit model for Larix gmelinii diameter distribution.②The structure of tree height is unimodal distribution curve,and the number of tree is most when tree height is 8 class.The fitting precision of Clare function for L.gmelinii height is best.③The L.gmelinii tree height increases with the increase of its diameter,and this correlation can be expressed in Wykoff equation.④ There is a positive correlation between L.gmelinii diameterat breast height and canopy.The fitting results of Monomolecular function is better.⑤ The average angular dimension of trees is 0.515,and the trees is with randomly distribution pattern.⑥The average stand size is middle when calculated by diameter at breast height,height and canopy.⑦ The average rate of mingling for trees is 0.327 with weak degree mixed.Therefore,the study area is characterized by a typical natural forest for L.gmelinii.