宁波石栎-木荷天然常绿阔叶混交林的树高-胸径模型

The natural evergreen broad-leaved mixed forest is a typical zonal vegetation type in Ningbo area. Studying the height-diameter at breast height (DBH) relationship model of this stand type can provide a theoretical reference for forest growth prediction, forest management, and forest resource inventory of the natural evergreen broad-leaved mixed forest in Ningbo area. In this paper, taking the natural evergreen broad-leaved mixed forest of Lithocarpus glaber - Schima superba, which is common in Ningbo area, as the research object, 30 commonly used empirical height - DBH models were selected. Through five model evaluation indicators, namely the adjusted coefficient of determination (Ra2), root mean square error (RMSE), mean absolute error (MAE), relative mean absolute error (RMAE), and Akaike information criterion (AIC), the differences in fitting effects among the models were compared and analyzed to determine the appropriate height - DBH model. The results showed that except for M23 which could not be solved, the other 29 models could be solved. Among the 29 models, M09, M12, and M26 performed excellently in the five model evaluation indicators, and M09 and M12 were better than M26, indicating that both M09 and M12 are appropriate height - DBH models for the natural evergreen broad-leaved mixed forest of Lithocarpus glaber - Schima superba. If the fitting effect of the modeling data is given priority, it is recommended to select M09, with Ra2 = 0.9141; if the fitting effect of the test data is given priority, it is recommended to select M12, with Ra2 = 0.9126.

天然常绿阔叶混交林是宁波地区的典型地带性植被类型，研究该林分类型的树高-胸径关系模型，可为宁波地区的天然常绿阔叶混交林的林木生长预测、森林经营管理、森林资源清查等提供理论参考。本文以宁波地区常见的石栎-木荷天然常绿阔叶混交林为研究对象，选用30个常用的树高-胸径经验模型，通过5个模型评价指标即调整决定系数（Ra2）、均方根误差（RMSE）、平均绝对误差（MAE）、相对平均绝对误差（RMAE）和Akaike信息准则（AIC）比较分析模型之间的拟合效果差异，从而确定适宜的树高-胸径模型。结果表明，除M23无法求解，其余29个模型均可求解。29个模型中，M09、M12和M26在5个模型评价指标中表现优异，M09和M12优于M26，说明M09和M12均为适宜的石栎-木荷天然常绿阔叶混交林树高-胸径模型。若优先考虑建模数据的拟合效果，建议选用M09，Ra2=0.9141；若优先考虑检验数据的拟合效果，建议选用M12，Ra2=0.9126。