Abstract:Based on the study of natural thinning process in plant populations beingdescribed by predecessors, the authors induced a theoretical model describing the wholedensity change process combined with self-adaptive and general model (SGM), ie.1nN=a1n2S+b1nS+c, where N and S represent population density and mean basal areaper plant, and a, b and c are parameters. It was found that the groWth process ofplants shown in the model is a kind of the Gompertz Curve. Meantime, the authorsproposed a tree density effect model in the stand that can be used in different siteconditions and growth stages. The model is described as N=exp (0.0462994H0.00299305 In2S-1.221487H0.01501599lnS+ 6.253176H0.189734), which is very well proved by observed data fromCastanopsis kawakamii population density, and which is very useful in practice and willprovide a scientific basis for forest management.