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    贺梦莹, 董利虎, 李凤日. 长白落叶松−水曲柳混交林冠幅预测模型[J]. 北京林业大学学报, 2020, 42(7): 23-32. DOI: 10.12171/j.1000-1522.20190250
    引用本文: 贺梦莹, 董利虎, 李凤日. 长白落叶松−水曲柳混交林冠幅预测模型[J]. 北京林业大学学报, 2020, 42(7): 23-32. DOI: 10.12171/j.1000-1522.20190250
    He Mengying, Dong Lihu, Li Fengri. Crown width prediction models for Larix olgensis and Fraxinus mandshurica mixed plantations[J]. Journal of Beijing Forestry University, 2020, 42(7): 23-32. DOI: 10.12171/j.1000-1522.20190250
    Citation: He Mengying, Dong Lihu, Li Fengri. Crown width prediction models for Larix olgensis and Fraxinus mandshurica mixed plantations[J]. Journal of Beijing Forestry University, 2020, 42(7): 23-32. DOI: 10.12171/j.1000-1522.20190250

    长白落叶松−水曲柳混交林冠幅预测模型

    Crown width prediction models for Larix olgensis and Fraxinus mandshurica mixed plantations

    • 摘要:
        目的  基于黑龙江省尚志市帽儿山林场和一面坡林场长白落叶松−水曲柳混交林24块标准地的3 164株长白落叶松样木及3 574株水曲柳样木的数据,分别构建了长白落叶松和水曲柳的冠幅模型。
        方法  通过分析不同混交方式林分内长白落叶松和水曲柳冠幅的变化规律及其与林木竞争因子的关系,从6种常用的线性和非线性基础冠幅模型中选取最优模型,并将混交比例Si和树木在混交带内位置P作为哑变量,加入其他树木变量和林分变量,分别构建长白落叶松和水曲柳的冠幅模型,并对所构建的模型进行评价。
        结果  长白落叶松和水曲柳冠幅在不同混交比例Si和混交带不同位置P下差异显著;冠幅与DDH(林木胸径与林分优势木胸径之比)和HDH(林木树高与林分优势高之比)成正相关,与大于对象木的胸高断面积之和(BAL)成负相关,与距离无关的竞争因子可以反映树木的竞争压力,对冠幅具有影响;长白落叶松冠幅与冠长率(CR)成正相关,与高径比(HD)成负相关;水曲柳冠幅与水曲柳优势木平均高(H0Fra)成正相关,与高径比(HD)成负相关。包含混交比例哑变量Si和混交带位置哑变量P的长白落叶松和水曲柳冠幅模型拟合冠幅(CW)的Ra2分别为0.564 2和0.545 9,加入树木变量和林分变量后长白落叶松和水曲柳冠幅模型拟合CW的Ra2分别为0.674 5和0.589 6。
        结论  包含混交带位置哑变量P、混交比例哑变量Si、树木变量(CR和HD)、林分变量(H0Fra)的长白落叶松和水曲柳冠幅模型具有较好的拟合效果及预测精度。因此,本研究所构建的冠幅模型可以很好地预测混交林内长白落叶松和水曲柳的冠幅,为进一步研究混交林树木树冠结构奠定了基础。

       

      Abstract:
        Objective  Based on the data of 3 164 Larix olgensis sample trees and 3 574 Fraxinus mandshurica sample trees from 24 sample plots in mixed plantations from Maoershan Mountain Forest Farm and Yimianpo Forest Farm in Shangzhi City, Heilongjiang Province of northeastern China, the crown width models for Larix olgensis and Fraxinus mandshurica were developed.
        Method  By analyzing the variation rules of crown width of Larix olgensis and Fraxinus mandshurica in different mixed stands and the relationship between crown width with forest competition factors, the best model was selected from the basic models of six commonly used linear and nonlinear crown width models. The mixed proportion Si and the tree position P in the mixed strip were taken as dummy variables, and other tree variables and stand variables were added. The crown width models of Larix olgensis and Fraxinus mandshurica were developed, and the fitting effects of the models were evaluated.
        Result  The crown width of Larix olgensis and Fraxinus mandshurica was different in different mixed proportion Si and different position P in the mixed strip. The results showed that the ratio of tree DBH to dominant tree diameter (DDH) and the ratio of tree height to dominant tree height (HDH) were positively correlated with crown width, and the basal area of larger trees (BAL) was negatively correlated with crown width. Distance independent competition factors can reflect the competitive pressure of trees and have effect on crown width. The results showed that the crown ratio (CR) was positively correlated with crown width of Larix olgensis, the ratio of total tree height to DBH (HD) was negatively correlated with crown width of Larix olgensis, the dominant tree height of Fraxinus mandshurica (H0Fra) was positively correlated with crown width of Fraxinus mandshurica, the HD was negatively correlated with crown width of Fraxinus mandshurica. For the crown width models of Larix olgensis and Fraxinus mandshurica with the dummy variable P and Si, the Ra2 was 0.564 2 and 0.545 9, and for the crown width models of Larix olgensis and Fraxinus mandshurica with the tree variables (CR and HD) and stand variable (H0Fra), the Ra2 was 0.6745 and 0.5896.
        Conclusion  The crown width models of Larix olgensis and Fraxinus mandshurica, including the dummy variable Si and P, tree variables (CR and HD) and stand variable (H0Fra), have good fitting effects and prediction accuracy. Therefore, the crown width models established in this study can well predict the crown width of Larix olgensis and Fraxinus mandshurica in mixed plantations, and provide a basis for further study on the crown structure in mixed plantations.

       

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