Study On Tree Species Planning In The Urban Green Space Ecosystem

With the rapid development of urbanization, urban environment have increasingly worsened. Construction of urban green space ecosystem aimed at improving environment is the development trend of urban green space at present. Zonal vegetation is vital to urban green space ecosystem construction. Ecological knowledge knowed by humankind mostly come form the study to natural vegetation system. Zonal vegetation, as the cyclostyle or frame of reference of urban green space ecosystem restoration, offers important reference to objective enactment and objective species selection and proportion configuration of urban green space ecosystem restoration. It is necessary to construct urban green space ecosystem that has high proportional zonal vegetation and steady structure and high ecology benefit, therefore the tree species composition and structure characteristics of zonal vegetation and ecology theory contained in the zonal vegetation are use for reference to tree species planning.Firstly, the whole-length study foundation, namely the zonal vegetation, was analyzed in this thesis. Based on the analysis of concept and cause of formation of zonal vegetation, the importance of tree species composition and community structure of zonal vegetation to steady urban green space system construction was explained, and ecology theory contained in the zonal vegetation as the theory base of tree species planning in the urban green space ecosystem construction was put forward.Secondly, from the theory analysis point of view obtaining, theory correlative with tree species planning in the urban green space ecosystem construction which based on zonal vegetation was by the numbers discussed. Circumfused with the route of tree species planning and times development, it was suggested that the most important in the current urban green space construction should be aimed at improving urban ecology environment under the progressively polluted modern urban circumstance, then environment beautification was only taken into account. Accordingly, tree species selection and application should be give prominence to ecology benefit, especially the tree species selection and planning in the outskirts of a city should be more pay attention to the application and construction of zonal natural vegetation. Moreover, tree species planning principia in the urban green ecosystem construction was put forward to abide by. Based on the analysis of objective zonal vegetation type and tree species composition and structure characteristic, the method of tree species selection and proportion configuration was discussed in the urban green ecosystem construction. Based on the stability of zonal vegetation and advantages and disadvantages of alien tree species, the principia of selection and planning of alien tree species was put forward.Thirdly, from the demonstration analysis point of view obtaining, actuality of tree species planning in our urban green space was studied. Controlled with ecology theory contained in zonal vegetation and taken tree species planning text of Changchun, Qingdao, Nanjing and Liuzhou as study object, issue about tree species selection and proportion configuration in the urban green space ecosystem was analyzed. The results showed that application of zonal tree species in the administration scale of city accounted for a low proportion in the tree species planning text of urban green space though the planning floristic species showed their zonal characteristic. Planting trees on the suitable sites condition was difficult to realize. The diversity of tree species with less kind was not abundant and the variety was single. There was not constructive species and dominant species and companion species of artificial community in the tree species planning text. The tree species proportion didn't accord with the rule of natural vegetation.Finally, from the question discussion point of view obtaining, the content compilation of tree species planning was studied in the urban green space ecosystem construction. Based on the analysis of advantages and disadvantages of predominant and backbone tree species and the absent direction basis of tree species proportion configuration application, the content compilation of tree species selection and proportion configuration should be farther studied in the urban green space ecosystem construction.In this paper the results showed that the function of zonal vegetation should be noticed in the urban green space ecosystem construction and the ecological theory contained in the zonal vegetation should be consulted in the tree species planning.