Study On The Forest Stand Spatial Structure Optimization Technology For Larch-Betula Platyphylla Mixed Forest Stand In Daxing’ An Mountain

Taken the nature Larch-Betula platyphylla mixed forest in Daxing’an mountain as example, the particle makes the detailed procedure for the optimization of spatial structure based on the investigation for all the trees in the18sample plots of3forest types. The method makes the analysis based on the indexes of uniform angle index、mingling、neighborhood comparison and taken the3forest types with4trees of neighborhood. Moreover, the particle simulates the detailed operation which is based on the8and14plots to test the optimization principle.The results showed that the whole spatial distribution for the nature mixed forest followed the aggregation distribution and the same to the main tree species in the forest stand. It was not difficult to adjust the uniform angle index for that the uniform angle index followed random distribution with the upper limits of0.517. Based on the frequency distribution for the uniform angle index of Larch-Betula platyphylla mixed forest, we concluded that the horizontal distribution of nature mixed forest did not affected by the tree species composition. It has weak mingling for the whole forest stand. The mingling of the coniferous and broad mixed forest stand was far larger than the Betula platyphylla stand and Larch forest stand. Generally speaking, the stability of the forest gets more strengthening with the larger of the mingling. During the process of optimization of spatial structure, Larch-Betula platyphylla mixed forest was adjusted to the coniferous and broad forest stand. As a result, it was necessary to adjust the mingling of the Larch-Betula platyphylla mixed forest. Based on the neighborhood comparison, this region was determined as the medium status.Based on the analysis of the3plots of the3typical forest types, the optimization of spatial structure was mild selecting cutting. Based on the analysis for the whole stand,3forest types and3sample plots, the particle comes up with the detailed principle for the spatial stand structure. The spatial structure for the forest stand had become the random distribution after the optimization for the forest and the mingling had been improved. The optimization selecting cutting could improve the spatial structure of the forest. It will need long time for the natural succession process. Besides, the environment and the resource can be widely used after the selecting cutting.