Abstract: In order to optimizationally control the defoliating insects in Picea mongolica forest, an artificially simulative defoliation experiment was carried out to study the interaction between plants and insects in the ecosystem. The results show that under certain defoliation rate, the seedlings of P.mongolica had the effects of compensation and overcompensation. The models of the effects were established based on a group of different macroscopic growth index, and correspondingly, the points of compensation and overcompensation were obtained.

Key words: Picea mongolica, Defoliating insects, Compensation, Overcompensation, community characteristic, fertilization mode, soil layer, soil fungi, Phyllostachys violascens stand