Effect of Thinning on Spatial Structure of Spruce-fir Mixed Broadleaf-conifer Forest Base on Crop Tree Management

Objective  The aim of this study is to provide the guidance and reference for formulating forest management measures and completing the system of effectiveness evaluation of forest management by analyzing the change of crop tree before and after the thinning based on the crop tree management.

Method  According to the theory of close-to-nature forest management, the crop trees were selected and interference trees were fell based on 6 Spruce-fir mixed forest sample plots each in a area of 1 hm². The change of the spatial structure parameters of crop trees and evaluation index of the stand spatial structure were computed and analyzed after combining the theory of structure-based forest management.

Result  (1) The isolation degree of species within the spatial structure unit was further improved; the light conditions of forest got better; the pressure of competition of crop tree was reduced; on the whole, the spatial distribution pattern was optimized. (2) The evaluation index of the stand spatial structure was further improved and the level of stand spatial structure showed the trend of steadily.

Conclusion  The thinning based on the crop tree management can realize the objective of optimizing the spatial structure of crop tree and keep the stabilization of the stand spatial structure. That means that it can accomplish the specific objective of optimizing the growing space of crop tree under the premise that the status of stands spatial structure are not destroyed and the level of stands spatial structure is not lower. The thinning can create more room for promote the economic benefits and ecological benefits of forest. It can provide a reference to the accurate culture and management of similar forest in Changbaishan Mountain regions and the monitoring and evaluation of the effect of forest management.