Synthetical Capability Quantification and Selection of Gardening Trees in Hexi of Gansu Province

Tree species selection is the premise of a town in arid desert area to realize greening, beautifying, cleaning and city's sustainable development. Based on the principles of tree suitable for local condition, natural structure, outstanding features, rich and colorful, and function optimization, the 12 basic tree and shrub species, the 41 main ones, the 54 common ones and the 47 marginal alternative ones for town gardening of Hexi region in Gansu are selected by using the method of Synthetically Evaluation of Level Structure Analysis. Among the 12 ones 2 species are evergreen trees, 7 broad leave trees, 1 shrub; 7 of them from local area and nearly a half species are introduced from outside areas. Among the 41 ones there are 3 evergreen species, 24 broad leave tree species, 14 shrubs; 14 of them from local species, 3/4 from outside areas.