南京林业大学学报（自然科学版）
南京林業大學學報（自然科學版）
남경임업대학학보（자연과학판）
Journal of Nanjing Forestry University (Natural Science Edition)
2015年
6期
74-80
,共7页
落叶松人工林%枝条直径%枝条长度%非线性混合模型
落葉鬆人工林%枝條直徑%枝條長度%非線性混閤模型
락협송인공림%지조직경%지조장도%비선성혼합모형
larch plantation%branch diameter%branch length%nonlinear mixed model
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0．7837和0．8657，均方根误差（ RMSE）分别为0．3777和0．2866，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。
基于95株落葉鬆解析木、843箇枝條實測數據，構建瞭枝條直徑和長度的傳統非線性模型、含樹木變量的非線性模型、非線性混閤模型和含有誤差結構的非線性混閤模型，比較瞭各模型的擬閤精度，分析瞭枝條直徑和長度的變化規律。結果錶明：含有誤差結構的落葉鬆人工林枝條直徑和長度非線性混閤模型擬閤精度最優，決定繫數R2分彆為0．7837和0．8657，均方根誤差（ RMSE）分彆為0．3777和0．2866，且消除瞭異方差現象，獨立樣本檢驗結果也證實該模型是最優預測模型；落葉鬆人工林枝條直徑和長度與枝條所在位置和樹木胸徑、冠幅、高徑比緊密相關，在樹冠頂部分佈的一級枝條直徑和長度都較小，而在樹冠底部分佈的則較大，樹冠下部枝條的直徑和長度受樹木形態因子的影響更明顯。
기우95주락협송해석목、843개지조실측수거，구건료지조직경화장도적전통비선성모형、함수목변량적비선성모형、비선성혼합모형화함유오차결구적비선성혼합모형，비교료각모형적의합정도，분석료지조직경화장도적변화규률。결과표명：함유오차결구적락협송인공림지조직경화장도비선성혼합모형의합정도최우，결정계수R2분별위0．7837화0．8657，균방근오차（ RMSE）분별위0．3777화0．2866，차소제료이방차현상，독립양본검험결과야증실해모형시최우예측모형；락협송인공림지조직경화장도여지조소재위치화수목흉경、관폭、고경비긴밀상관，재수관정부분포적일급지조직경화장도도교소，이재수관저부분포적칙교대，수관하부지조적직경화장도수수목형태인자적영향경명현。
The objective of this work was to establish the models for predicting branch diameters and lengths in the larch plantations. The traditional nonlinear model, including the trees variable nonlinear model, the nonlinear mixed models and the nonlinear mixed model containing the error structure of branch diameter and length were constructed based on the data of 843 standard branches collected from 95 sample trees, and the prediction accuracies were also evaluated, by the analyses of the changing rule of the branch diameters and lengths. The results indicated that the nonlinear mixed model with the error structure for the branch diameter and length prediction was the best, with R2 values of 0. 783 7 and 0.865 7, and RMSE values of 0.377 7 and 0.286 6, respectively, and the phenomenon of heteroscedasticity was also elminated. The validation by using independent samples also verified that this model was optimal. The model showed that the branch diameter and length were closely related to branch location within the living crown and diameter at breast height, crown width, ratio of height to diameter. The diameter and length of branches were smaller in the top but was bigger in the bottom of crown. The diameter and length of branches in the bottom of crown were more obvious in different trees.
