selection forest
2.In natural forest, 94% of the volume of CWD consisted of fallen logs, 5.8% of standing dead trees and 0.2% of cut stumps. Most of the volume of CWD belonged to 2～40 cm diameter class. In selection cutting forest, 55% of the volume of CWD consisted of cut stumps, 41% of fallen logs, 4% of stand standing dead tree, Most of the volume of CWD belonged to 11～50 cm diameter class.
5.The Fengshui woods at Wanshitou Village of Shishan Town is the well-conserved natural district secondary stand in Nanhai District.Study on its floristic composition and community structure is of great significance to the tree species selection and mixed types for the transformation from coniferous plantations into monsoon evergreen broad-leaved forest.
6.In order to provide scientific evidence for selection of tree species,spatial arrangement in the establishment of water conservation forests in the low mountain and hilly areas in the upper reaches of the Yangtze River,the hydrologic traits of the vertical structure of the four forest types(?Pinus elliotii,Alnus cremastogyne,Robinia pseudoacacia?,and mixed pine and alder forest)in Wancanggou small watershed in the valleys of the Jialingjiang River were analyzed in this paper.
8.We shall emphatically study the layout and planning and control mode of ecological construction of sand protection and control, and research and apply optimized plantation of indeciduous forest and grass, and selection and breeding of indeciduous plant for sand protection and control and drought resistance and its facility and technology.
