Richards函数与Schnute生长模型的比较

在分析Richards生长函数的假设和性质的基础上,探讨了Richards方程在实际应用时所出现的两个特例(m<0),并介绍了Schnute生长模型的假设及推导过程。通过详细比较Richards函数与Schnute生长模型的假设、公式推导、参数之间关系以及两个模型的函数表达式和拟合实例,论证了Schnute模型并非为一新的理论生长方程,而与Richards方程完全相同,属于Richards函数的另一种解的表达式。当Richards方程中参数m不受约束时,完全可以拟合一些特殊的生长曲线,结果与Schnute模型完全相同。

THE COMPARISON BETWEEN RICHARDS GRORTH FUNCTION AND THE SCHNUTE MODEL

Based on analysing hypothesis and attributesof the Richards growth function, this paper presents two special cases of Richards equation when it is applied to forestry. Hypothesis and derivation procedure of the Schnute's growth model are also given. The model assumption, equations derivation and the parametric relationship as well as the model expressions and fitting results between the Richards growth function and Shnute model are compared. From the results of the comparison between two models, it is showed that the Schnute growth function is not same a new theoretical function as Richards function. It is concluded that the Schnute model is an another expression of Richards growth function. Therefore, a generalized growth functiondeveloped by Schnute has some new properties.