【目的】 利用立地指数法对不同林龄福建柏(Fokienia hodginsii)人工林进行立地质量评价,旨在为福建省林分立地质量调查提供科学依据。【方法】 以福建省内不同林龄的福建柏人工林为研究对象,选择6个常用的理论生长方程:冈珀茨公式(Gompertz)、理查德兹式(Richards)、韦伯公式(Weibull)、科尔夫公式(Korf)、逻辑斯谛公式(Logistic)、舒马赫公式(Schumacher),对福建柏林分年龄与优势木平均高数据进行拟合,根据决定系数(R²)、绝对误差(MAE)和均方根误差(RMSE)对各方程的拟合性能进行评价,编制出适用于福建省福建柏人工林的立地指数表。【结果】 Korf模型拟合的R²最大、RMSE和MAE最小,因此选择Korf方程作为最优导向曲线方程。通过绘制104株优势木树高平均生长量和连年生长量变化折线图,结合各龄阶优势高变动系数确定福建柏人工林的基准林龄为20 a,根据基准年龄时优势高变动范围确定指数级距为2 m。利用比例调整法编制出立地指数表,表明福建省大部分福建柏人工林立地指数处于中等水平,只有7%的标准地其立地指数处于较高水平。以坡向和土层厚度2个指标作为划分立地类型的主导因子,发现福建省内大部分福建柏人工林土层深度较浅,且阳坡的人工林数量较高于阴坡。【结论】 本研究构建了该地区福建柏人工林分树高生长模型,可预测福建柏林分的生长量和收获量。经卡方检验和落点检验,立地指数表可应用于实践;使用所编立地指数表进行立地质量评价,可更好地量化不同林地的生产力。

【Objective】 The site index method was used to evaluate the site quality of Fokienia hodginsii plantations with different forest ages, so as to provide investigation in Fujian Province, China. 【Method】 Taking F. hodginsii plantations of different forest ages in Fujian Province as the research object, six commonly used theoretical growth equations were selected to calculate the average age of F. hodginsii and dominant trees. The fitting performance of each equation was evaluated according to the coefficient of determination (R²), the absolute error (MAE) and the root mean square error (RMSE), compiled the site index table applicable to Fujian cypress plantation in Fujian Province,aiming to provide a scientific basis for the quality investigation of forest stand in Fujian Province.【Result】 The results show that the R² of the Korf equation was the largest, and the RMSE and the MAE were the lowest, so the Korf equation was selected as the optimal steering curve equation. By plotting the data of 104 dominant tree height, the average growth rate of dominant height and the change of annual growth rate were plotted, and the base age of F. hodginsii plantation was determined to be 20 years according to the variation coefficient of dominant height of each age class, which was determined according to the variation range of dominant height at the base age. The index level distance was 2 m, and the site index table compiled by the proportional adjustment method showed that the site index of most of Fujian cypress plantations in Fujian Province was at a medium level, and only 7% of the standard sites showed a higher level of site index.Taking two indicators of slope aspect and soil thickness as the dominant factors for the classification of site types, it was found that most of the F. hodginsii plantations in Fujian Province had shallow soil depth, and the number of plantations on sunny slopes was higher than that on shady slopes. 【Conclusion】 The results of this study can be used to construct a tree height growth model for F. hodginsii plantation stands in the region, and to predict the growth and harvest of F. hodginsii stands. Evaluation of stand quality was carried out using the compiled site index table to better quantify the productivity of different sites, which can be applied in practice after chi-square test and drop point test.