文献类型：期刊文献

中文题名：落叶松人工林枝条直径和长度的非线性混合模型

英文题名：Nonlinear mixed models of branch diameter and length in larch plantation

作者：陈东升[1] 孙晓梅[1] 李凤日[2]

第一作者：陈东升

机构：[1]中国林业科学研究院林业研究所国家林业局林木培育重点实验室;[2]东北林业大学林学院

年份：2015

卷号：39

期号：6

起止页码：74-80

中文期刊名：南京林业大学学报：自然科学版

收录：CSTPCD;;北大核心:【北大核心2014】；CSCD:【CSCD2015_2016】；

基金：国家自然科学基金青年基金项目(31300536);国家自然科学基金重点项目(31430017)

语种：中文

中文关键词：落叶松人工林;枝条直径;枝条长度;非线性混合模型

外文关键词：larch plantation; branch diameter; branch length; nonlinear mixed model

分类号：S758.1

摘要：基于95株落叶松解析木、843个枝条实测数据,构建了枝条直径和长度的传统非线性模型、含树木变量的非线性模型、非线性混合模型和含有误差结构的非线性混合模型,比较了各模型的拟合精度,分析了枝条直径和长度的变化规律。结果表明:含有误差结构的落叶松人工林枝条直径和长度非线性混合模型拟合精度最优,决定系数R2分别为0.783 7和0.865 7,均方根误差(RMSE)分别为0.377 7和0.286 6,且消除了异方差现象,独立样本检验结果也证实该模型是最优预测模型;落叶松人工林枝条直径和长度与枝条所在位置和树木胸径、冠幅、高径比紧密相关,在树冠顶部分布的一级枝条直径和长度都较小,而在树冠底部分布的则较大,树冠下部枝条的直径和长度受树木形态因子的影响更明显。
The objective of this work was to establish the models for predicting branch diameters and lengths in the larchplantations. The traditional nonlinear model, including the trees variable nonlinear model, the nonlinear mixed modelsand the nonlinear mixed model containing the error structure of branch diameter and length were constructed based on thedata of 843 standard branches collected from 95 sample trees, and the prediction accuracies were also evaluated, by theanalyses of the changing rule of the branch diameters and lengths. The results indicated that the nonlinear mixed modelwith the error structure for the branch diameter and length prediction was the best, withR2 values of 0. 783 7 and0.865 7, and RMSE values of 0.377 7 and 0.286 6, respectively, and the phenomenon of heteroscedasticity was alsoelminated. The validation by using independent samples also verified that this model was optimal. The model showed thatthe branch diameter and length were closely related to branch location within the living crown and diameter at breastheight, crown width, ratio of height to diameter. The diameter and length of branches were smaller in the top but wasbigger in the bottom of crown. The diameter and length of branches in the bottom of crown were more obvious in differenttrees.