Study On Composition Structure And Dynamic Of Typical Community Of The Green Lands Of Parks In Shanghai

Green space in park is an important part of urban green space, and the plant community is the basic component of urban green space. Structural characteristics of the plant community decide the quality of landscape of plants and ecological functions in parks. A scientific and reasonable structure of plant communities plays an important role in the process of protecting and beautifying the environment, enhancing the effect of landscape in parks and maintaining ecological balance in urban. This paper studies the species composition, quantitative characteristics,structure characteristics, species diversity, dynamics of plant communities in parks of Shanghai, and evaluates quality of landscape of plant communities in the survey. Finally, based on the study of plant community, This paper proposes suggestions about further optimization of present plant communities of parks in Shanghai.The results were as follows:(1) There are a total of 247 kinds of plant species in the 136 surveyed field of 38 city parks,belonging to 101 families.The application of plants is single. The tree layer with dominant species of Cinnamomum camphora,Metasequoia glyptostroboides, Taxodium ascendens, Trachycarpus fortunei, Ligustrum lucidum whose important values (IV) were 16.78,10.09, 8.43,4.49 and 4.44 respectively; second, the shrub layer that was dominated by Gardenia jasminoides, Fatsia japonica, Osmanthus fragrans,Rhododendron simsii,Pittosporum tobira whose important values (IV) were 9.49,9.02,8.37,5.71 and 4.90 respectively. In aspects of source of plants,there are 125 local plants by 40.32% and 185 exotic species by 59.68% which show that the types of distribution dominated by exotic species and assisted with exotic species in plant community of parks in Shanghai. Distribution of families constitutes main part of tropical families which have 42 families by 41.58%. Distribution of genera mainly is generals in north temperate zone by 24.5% and extensive tropical generas by 21.5%. It embodies that it is North subtropical climate in Shanghai and shows that it transitions from the subtropical to temperate.(2) Anglicizing structure of plant community of selected typical samples. Level structure is divided into two kinds of pure forest communities and nitrogen fixation of forest communities which is given priority to communities mixed with evergreen and deciduous broad-leaf trees.The zonal features is obvious. Vertical structure is divided into 5 types witch are arbor-shrub-herb communities, arbor-herb communities, shrub-herb communities, arbor-shrub communities and arbor communities. Arbor-shrub-herb communities have the largest number. The tree layer dominated by deciduous trees tree species, shrub layer is in the ascendant with evergreen tree species.(3) Comparatively analysising the diversity of species from the angle of the community structure and park types. It is concluded from community level structure perspective that the diversity of species increases with the increasing of the number of plant species. In community vertical structure,the order of the range of diversity of species is arbor-shrub-herb> arbor-herb> arbor-shrub> arbor> shrub-herb. In six types of park comparison, the order of the Shannon-Wiener index of diversity of species is botanical garden> zoo sorting> memorial park > forest park> comprehensive park> sports park; the order of the Smipson index of diversity of species is botanical garden> zoo sorting> memorial park> sports park> forest park> comprehensive park; the order of the Pielou index of diversity of species is botanical garden> zoo sorting> sports park> memorial park> forest park> comprehensive park. The discretion of the species diversity in parks has particular relations with the nature and function of parks.(4) Analysis of forests update shows that community of plant in Shanghai parks will grow steadly in a long period and will be succeeded naturally by the communities mixed with evergreen and deciduous broad-leaf trees witch with dominant species of Cinnamomum camphor a and Ligustrum lucidum finally without human interference.(5) Assessment on the quality of landscape of plant typical community in Shanghai parks by AHP and fuzzy evaluation shows that the bad taking up 2.21%, medium taking up50.74%, and good taking up 47.05%. This show that the quality of landscape in Shanghai parks is in above the average overall level.