Comparative Study on Different Thinning Methods of Pinus tabulaeformis Plantation in Western Liaoning
The increment of DBH,height and crown width of?Pinus tabulaeformis?plantation,which was 47 years and located in Beipiao City,Western Liaoning and was thinned 5 years ago by close-to-nature thinning method and traditional thinning method separately with thinning intensity of 10%in tree number,and its proportion distribution of tree number in DBH,height and crown width according to different grades,were studied comparatively in this paper.The results showed that:compared to the traditional thinning method of cutting 4 to 5 grade trees,the close-to-nature thinning method,which was target-tree oriented and to cut 2 to 3 grade trees,had overall promoted the DBH and height growth of the retained?Pinus tabulaeformis?trees and successfully kept the stability of the forest DBH distribution.After thinning,the proportion distribution curve of tree number according to different DBH grades of the retained trees shifted to the right as a whole.The accelerating effect of traditional thinning and close-to-nature thinning on the height growth of the retained trees differed in various degrees,and the latter was better than the former.However,the two thinning methods mentioned hadn't promoted the crown width growth of the retained trees significantly.It was advised that the thinning intensity in tree number should be above 20%to show the advantage of the close-to-nature thinning method.
万方数据
维普
