为满足在吉林省开展古树群调查方法试点的需要,利用第二次全国古树名木普查及全国生物量调查建模等项目所获取的4 235株样木的树龄-胸径成对数据,基于Richards、Logistic、Gompertz等常用生长函数,构建10个主要树种(组)(云杉、冷杉、红松、落叶松、蒙古栎、桦树、榆树、椴树、杨树和水胡黄)的单木胸径平均生长模型,并确定各树种组判定古树的胸径阈值。结果表明:1)基于常用生长函数拟合的胸径生长模型中,Richards函数的效果为最佳;2)10个主要树种组的胸径生长模型的决定系数(R²)均在0.7以上,总体相对误差(E_TR)都在±3%以内。构建的模型可为吉林省第三次古树名木普查中确定古树胸径阈值、估测树龄作参考;其建模方法及胸径阈值确定方法也可为其他省份的相关工作提供借鉴。

To meet the requirements of conducting a pilot study on surveying methods of ancient tree groups in Jilin Province,with the paired data of tree age and diameter at breast height (DBH) of 4,235 sample trees obtained from the 2nd National Census of Ancient and Notable Trees and the National Biomass Survey Surveying and Modeling Program,we developed DBH average growth models for individual trees of ten major tree species or groups (spruce,fir,Korean pine,larch,Mongolian oak,birch,elm,linden,aspen,and walnut) in Jilin Province by using the three common growth functions,involving Richards,Logistic and Gompertz,and the thresholds of DBH for identifying ancient trees of each tree pecie or group were determined.The results showed:1) Among the commonly used growth functions,the Richards function was found to be the most effective for fitting DBH growth models;2) The values of the coefficient of determination (R²) of the DBH growth models for the ten main tree species groups were all above 0.7,and the values of the total relative error(TRE) were within ±3%.The established models may be referred to determine the DBH thresholds of ancient trees and to estimate the age of ancient trees during the 3rd National Census of Ancient and Notable Trees in Jilin Province;and the modeling approach and the method for determining the DBH thresholds of ancient trees can be used as references for other provinces.