5种Logistic模型在模拟杉木人工林胸高断面积分布中的应用

Application of Five Types of Logistic Models Imitating the Stand Basal Area Distribution of Chinese Fir Plantation

本文就Logistic及其改进模型在杉木人工林胸高断面积模拟中的应用进行了深入探讨。研究表明:在相同林分密度下,随立地指数增加,模型的模拟精度越高立地条件影响越大;在相同立地条件下,所有改进Logistic模型的模拟精度都受到林分密度影响;Logistic及其改进模型的模拟精度与林龄没有任何关系。对于某一具体植物种群,不同形式的Logistic模型的模拟精度主要受模型本身的影响。同另外4种Logistic模型相比,Z-Logistic模型参数最稳定,模拟精度最高,为模拟杉木人工林胸高断面积的首选模型。各改进模型的参数直接影响Logistic模型模拟的曲线形状,可作为形状参数使用。

The Logistic models are subjected toextensive application, because theycan reflect the basic regulation of population growth well. We discuss the application of Logistic models and their improved ones to imitate the stand basal area of Chinese Fir（ Cunninghamia lanceolata（Lamb. ） Hook. ） plantations. On the basis of same stand densi- ty, we found that with the increment of sit index, the higher the imitating precise, the more significant the influence of site quality to models; On the basis of same site quality, we found that stand density influences the imitating pre- cise of all the models. And we also found that there was no relationship between the imitating precise and stand age. As for the certain plant population, different type of models aced of their own accord. Compared with the other four types of Logistic Models, Z-Logistic Model had the most stable parameters and the highest imitating precise which, we think, is the best to imitating the stand basal area of Chinese Fir plantations. The parameters of improved models had direct influence on Logistic models to imitate the curve shape, using as shape parameters.