蒙古栎天然林单木生长模型的研究——Ⅱ.树高-胸径模型

Growth model for individual-tree in natural Quercus mongolicaforests——Ⅱ.Height-diameter model

【目的】预测和研究蒙古栎天然林的生长与发展规律,以更好地经营蒙古栎天然林。【方法】以蒙古栎天然林为研究对象,基于吉林省汪清林业局195块蒙古栎林固定样地的2期复测数据,通过分析已有的16个普通树高曲线模型和16个标准树高曲线模型并对比2种模型的拟合结果,建立蒙古栎林的单木树高曲线模型。【结果】最终确定的蒙古栎林最优普通树高曲线模型的决定系数R2为0.728,调整决定系数R2adj为0.721,均方根误差为2.291m,相对均方根误差为0.158,平均误差为0.118m,平均绝对误差为1.794m。最优标准树高曲线模型的决定系数R2为0.907,调整决定系数R2adj为0.901,均方根误差为1.479m,相对均方根误差为0.114,平均误差为0.094m,平均绝对误差为1.381m。【结论】增加了树木和林分因子的标准树高曲线模型,其精度较普通树高曲线模型有大幅提高。最优的蒙古栎单木标准树高曲线模型自变量包括胸径、林分每公顷株数、林分每公顷断面积、优势木平均高。建立的单木标准树高曲线模型有较好的生物学意义,可为吉林省汪清地区蒙古栎天然林的生长预测提供依据。

【Objective】The individual-tree model for growth and development of natural Quercus mongolicaforest was established for better management of such forests.【Method】The data used to develop individual-tree height-diameter model for natural Quercus mongolica forest were collected from 195 permanent sampling plots in Wangqing Forest Bureau,Jilin province at two periods.Based on analyzing the existing 16 local height-diameter models and 16 general height-diameter models,individual tree height-diameter model for Quercus mongolica forest was developed and the results were compared with local and general height-diameter models.【Result】The values of fitting and testing statistics R2,R2 adj,RMSE,ERMSE,ME and MAEof the optimal local height-diameter model were 0.728,0.721,2.291 m,0.158,0.118 mand1.794 m,respectively.Those values for the optimal general height-diameter model were 0.907,0.901,1.479 m,0.114,0.094 m and 1.381 m,respectively.【Conclusion】The optimal general height-diameter model had higher precision than local one and the independed varibles included diameter,the number of trees per hectare,stand basal area per hectare,and average height of dominant trees.The height-diameter model established in this paper is biologically reliable for predicting the growth of Quercus mongolicaforest in Wangqing region of Jilin province.