Short-term Effects of Different Forest Management Practices and Spatial Structure of Pinus massoniana Stand

In order to understand the influence of conventional forest management practices on species composition and stand spatial structure of Pinus massoniana forest, P. massoniana plantation with 4 forest management practices in the Three Gorges Reservoir area were taken as the subject (i.e., no cutting; shrubs cutting; non- P. massoniana cutting and dominant P. massoniana cutting) , we analyzed community composition and quantitative features and spatial structure in 3 years post-treatment of each managements type by using 3 structure parameters, which are uniform angle index, neighborhood comparison and mingling intensity. The results show that different forest management practices significantly affect the species composition and degree of advantage species, the biodiversity of arbor layer decreased and that of shrub layer and herb layer increas obviously. Shrubs-cutting measure causes no obvious change on spatial distribution pattern. However, both non- P. massoniana cutting and dominant P. massoniana cutting practices improve the aggregation degree of stand spatial structure, and the average concentration increased as selective cutting intensity improve. Though different practices show no significant effects on neighborhood comparison of P. massoniana, selective cutting obviously improved mingling intensity. Hence, simple regulation on the structure of a species or a single tree level is not conducive to optimize P. massoniana forest stand structure. According to biological characteristics and functional status of tree species, selective cutting tree and maintained tree need to comprehensive determine, and moderate selective cutting intensity is more conducive to forest structural adjustment.