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    王烁, 董利虎, 李凤日. 人工长白落叶松枝条存活模型[J]. 北京林业大学学报, 2018, 40(1): 57-66. DOI: 10.13332/j.1000-1522.20170203
    引用本文: 王烁, 董利虎, 李凤日. 人工长白落叶松枝条存活模型[J]. 北京林业大学学报, 2018, 40(1): 57-66. DOI: 10.13332/j.1000-1522.20170203
    Wang Shuo, Dong Li-hu, Li Feng-ri. Branch survival models of planted Larix olgensis tree[J]. Journal of Beijing Forestry University, 2018, 40(1): 57-66. DOI: 10.13332/j.1000-1522.20170203
    Citation: Wang Shuo, Dong Li-hu, Li Feng-ri. Branch survival models of planted Larix olgensis tree[J]. Journal of Beijing Forestry University, 2018, 40(1): 57-66. DOI: 10.13332/j.1000-1522.20170203

    人工长白落叶松枝条存活模型

    Branch survival models of planted Larix olgensis tree

    • 摘要:
      目的木材的质量决定了它在生产中的价值, 优质的木材往往可以获得更高的利润。但是树干上节子的大小会严重影响木材的质量, 而节子是在枝条死亡后形成的, 所以通过研究枝条属性, 寻找合适的营林控制方式将对提高木材质量具有重要意义。
      方法本研究根据黑龙江省佳木斯市孟家岗林场、林口林业局和东京城林业局的10块长白落叶松人工林标准地中的70株落叶松枝解析数据, 分别建立传统的Logistic基础模型以及相应的广义线性混合模型(GLMM)来预测该地区长白落叶松的枝条存活状况, 并对模型进行拟合效果评价和独立性检验。
      结果枝条存活状态受树木自然整枝程度、枝条生长位置和树木间竞争等因素的影响, 在模型中, 冠长率(CR)可以反映树木自然整枝程度, 其参数值为正说明树木自然整枝程度较低时, 枝条大多处于存活状态。枝条相对位置(BRH)和枝条轮数(WHOLE)可以反映枝条的生长位置, 其参数值为负说明处于树冠上部的枝条由于受光充分而长势良好, 而处于树冠下部的枝条由于相互遮蔽而死亡。树高胸径比(HD)可以反映林木间的竞争情况, 其参数值为负说明激烈的竞争环境会使枝条存活概率降低。AIC、RMSE、AUC和模型判断正确率可以用于比较基础模型和广义线性混合模型的预测效果。经计算, 广义线性混合模型的AIC=801.67, RMSE=0.126, 均小于基础模型, AUC=0.9975, 模型判断正确率为97.9%, 均大于基础模型, 说明广义线性混合模型可以有效解决不同个体间存在差异的问题, 有利于提高枝条存活状态的预测精度。独立性检验结果显示模型预测精度良好。
      结论本研究可为长白落叶松人工林确定合理的经营措施, 提高木材质量提供理论依据。

       

      Abstract:
      ObjectiveThe quality of wood determines its value in production, and high-quality wood tends to earn higher profits. However, the size of the knot on the trunk can seriously affect the quality of wood, and the knot is formed after the death of branch. Therefore, by studying the properties of branches, looking for suitable ways of controlling the forest is of great significance to improve the quality of wood.
      MethodBased on the branch analysis data of 70 trees selected from 10 sample plots of Larix olgensis plantations in Mengjiagang Forest Farm of Jiamusi City, Linkou Forestry Bureau and Dongjingcheng Forestry Bureau, Heilongjiang Province of northeastern China, this paper develops classic Logistic model using traditional method and generalized linear mixed models (GLMM) to predict the branch survival of planted Larix olgensis tree. Goodness of fit tests and independence tests were implemented for all models.
      ResultThe branch survival was affected by many factors, like the degree of natural pruning of trees, the growth position of branches and the competition among trees.In the model, CR reflected the degree of natural pruning of trees, and the parameter value positive indicated that the natural pruning degree of trees was low and the branches were mostly in the living state.BRH and WHOLE reflected the growth position of branches in trees, and those negative parameter values showed that the branches in the upper part of the canopy grew well due to the sufficient light, and the branches in the lower part of the canopy died early due to mutual shadowing.HD reflected the competition between trees, and the negative parameter value showed that the intense competitive environment could reduce the survival probability of branches.AICs, RMSEs, AUCs and the correctness of model judgment can be used to compare the prediction effect of basic model and GLMM. The calculated AIC = 801.67, RMSE = 0.126, AUC = 0.9975 and the correctness of model judgment was 97.9% of GLMM. GLMM had obvious smaller AIC, smaller RMSE, larger AUC and larger correct rate. Thus, GLMM could efficiently solve the problem of the variation among different individuals, and improve the accuracy of predicting the branch survival status. The accuracy of the model was good in the independence test.
      ConclusionThis study would provide the theoretical basis for determining reasonable management measures and improving the timber quality for Larix olgensis plantation.

       

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