同龄林直径变动系数动态变化规律的初步研究

提出了林分水平上直径变动系数的平方动态变化模型，该模型能较好地描述直径变动系数平方变化的三种情形（减少，稳定和增加）从而得到了一种由林分平方平均直径预估算术平均直径的有效途径，通过应用杉木人工同龄林林分生长数据进行拟合，取得了令人满意的结果，与国外一种同类研究方法相比较，本文所提出了模型具有一定的机理性和更好的整体预估精度，研究还发现增加初始值后的模型可具有更佳的拟合效果，本研究结果可用于间伐后杉

A Preliminary Study on Dynamic Laws in Coefficient Variation of the Tree Diameter Even-aged stands

The dynamic models in stand level are developed for square coefficient variation of the tree diameter, which can be used to describe three states (decrease, stabilization, and increase) of square coefficient variation of the tree diameter, so it is an efficient way to predict arithmetic mean diameter via the quadratic mean diameter in stands. A satisfactory fitting has been obtained based on the growth data of even aged plantations of Chinese fir ( Cunninghamia lanceolata) . Compared with another method proposed by Knoebel and others, the models are of both certain mechanism and better prediction precision on the whole. It has been found that the fitting can be improved as the initial value is added. The result of this paper could be used to predict the arithmetic mean diameter and coefficient variation of the tree diameter in unthinned and thinned even aged plantations of Chinese fir.