| 高德祥,韦文长.滇西南巨尾桉人工林木根径、胸径与树高模型研究[J].林业调查规划,2022,(4):1-7 |
| 滇西南巨尾桉人工林木根径、胸径与树高模型研究 |
| Model of Root Diameter and DBH and Tree Height of Eucalyptus grandis×E.urophylla |
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| DOI： |
| 中文关键词: 巨尾桉人工林 根径 胸径 树高 数学模型 滇西南 |
| 英文关键词: Eucalyptus grandis×E.urophylla plantation root diameter DBH tree height mathematical model southwest Yunnan |
| 基金项目:云南省临沧市科技创新人才培养项目（202004AC100001-B14）. |
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| 中文摘要: |
| 为研究巨尾桉人工林林木根径、胸径与树高数学模型，在滇西南的双江县选取138株（其中建模样本103株，检验样本35株）树干健全、通直圆满、无分杈的巨尾桉人工林样木，采集其根径与树高、胸径与树高成对数据。利用SPSS 21.0回归分析，分别建立线性方程、对数曲线、指数曲线和Logistic曲线等11个数学模型，以决定系数（R2）、估计值的标准误（SEE）、均方差（RMSE）、平均绝对偏差(MAD)、相对误差（RS）、模型预估精度（P）、显著性(Sig)P值作为模型评价指标，对比11个模型的拟合效果。结果表明，11个根径—树高模型显著性（Sig）P<0.001，其中有9个模型的预估精度大于97%，回归方程达到极显著水平，拟合效果较好；11个胸径—树高模型显著性（Sig）P<0.001，其中9个模型的预估精度大于97%，回归方程达到极显著水平，拟合效果也较好。通过对各项评价指标进行比较分析，确定三次项曲线H=a0+a1DR+a2DR2+a3DR3是拟合效果最好的根径—树高数学模型，代入拟合参数后的根径—树高数学模型表达式为H=11.069901-0.729389DR+0.096782DR2-0.001984DR3；线性方程H=a0+a1D是拟合效果最好的胸径—树高数学模型，代入拟合参数的胸径—树高数学模型表达式为H=4.818702+0.891217D。 |
| 英文摘要: |
| In order to study the mathematical model of root diameter, DBH and tree height of Eucalyptus grandis×E.urophylla plantation, 138 sample trees (103 for modeling samples and 35 for testing samples) with perfect trunk, straight and complete and without branches were selected and the paired data of root diameter and tree height, DBH and tree height were collected. Using SPSS 21.0 regression analysis, 11 mathematical models such as linear equation, logarithmic curve, exponential curve and Logistic curve were established respectively. The fitting effects of the 11 models were compared with the evaluation indicators of determination coefficient (R2), standard error of estimate (SEE), mean square error (RMSE), mean absolute deviation (MAD), relative error (RS), model prediction accuracy (P) and significance (Sig) P value. The results showed that 11 root diameter-tree height models had significance (Sig) P<0.001, 9 models had an estimated accuracy greater than 97%, the regression equations reached a very significant level, and the fitting effect was good; 11 DBH-tree height model had significance (Sig) P<0.001, the prediction accuracy of 9 models was greater than 97%, the regression equation reached a very significant level, and the fitting effect was good. The comparative analysis of various evaluation indicators determined that the cubic curve H=a0+a1DR+a2DR2+a3DR3 was the root diameter-tree height model with the best fitting effect, and the mathematical model expression after substituting the fitting parameters was H=11.069901-0.729389DR+0.096782DR2-0.001984DR3; the linear equation H=a0+a1D was the DBH-tree height model with the best fitting effect, and the mathematical model expression after substituting the fitting parameters was H=4.818702+0.891217D. |
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