Selection Of Landscape Tree Species In Urban Green Space System

With the fast development of urbanization and population continues to increase, the ecological environment within cities also had varying degrees of deterioration. At this time, The ecological role of landscape trees and ornamental features is becoming more and more important in the construction of urban green space system. This article compares and analysis the progress and status of landscape tree species planning in both China and abroad, and puts forward the importance and necessity of establishing a stable plant communities and a complex community structure in the cities. At first, the article expounds the species classification standards and categorization of landscape trees, and discusses in detail their functions in improving the environment, building langcape space and production, which provide rich theory basis and support in landscape construction. At the same time, this article also studies the theory of landscape tree species planning. The research makes it clear some technical indexes through the discussion of the content,principles of landscape tree species planning,such as the scale between shrub and arbor tree,evergreen species and deciduous trees,native species and exotic species, and points out some principles in choosing the backbone tree species,tone and general tree species. In addition, The research also take Xingping city in Shaanxi province as an example in landscape tree species planning, discusses the general process of landscape tree species planning, which provide basic information and theoretical support in the following construction of urban green space system in Xingping.Xingping City, which covers an area of a total of 81 square kilometers and has good soil and clear four seasons, is located in Guanzhong Plain. Since Xingping changed from a county to a city in 1993, the whole citie has been expanding larger and larger, but so far, Xingping has not made the landscape tree species planning according to its background, nor did it organized a system survey and analysis of status of landscape tree species in Xingping, which result in unreasonable using of landscape trees, and seriously influencing the construction of reasonable urban ecological community and the improvements of environment. In this study, landscape tree species in 26 primary and secondary roads, 12 major publicgreen space and 7 residential area in Xingping were surveyed, and their species, origin, growth, distribution frequency, garden use, resistance, greening and beautifying effect were recorded. Some landscape tree species, including the key and dominant landscape tree species in Xingping are ascertained by means of a general investigation on the tree species in different type of landscapes in Xingping. Accordingly, in case of the deficiency of the tree species with local characteristics and the lack of diversity, some countermeasures about programming and selection of landscape and virescence arbor in Xingping for the future are proposed.