Studies And Assessments On Vegetation Characteristics In Urban Forests Of Shanghai

In this paper, we did research on types and characteristics of plant communities in urban green by using the methed of French-Swedish survey procedure, and established the classification system of plant communities in Shanghai urban-green space, then,compared with the artificial plants types of the She mountain and the Da jinshan island beside Shanghai. On the base of comprehensively research on urban green space in Shanghai urban area, an indices system was built by using the methods of Stratified analysis and Delphi. Some useful results are given as follows:(1).After more than 80 green units have been investigated on forests in the center of Shanghai,we investigated 489 plant-communities. 6 vegetation type groups, 17 vegetation types and 184 plant formations were classified according to the vegetation five class classification system"vegetation type group, vegetation type, vegetation subtype, plant formation, plant association".The results showed:Deciduous broad-leaved forest and evergreen broad-leaved forest are the main types of the artificial vegetation in Shanghai urban area.(2)The constitution of the city forest vegetation. In 362 kinds of plants of the articial plant-communities of Shanghai city forests, the tree is the most for 113 kinds , the percentage is for 31.2%, among them being known as the majority of the deciduous tree again, total 72 kinds about 200% of the evergreen tree in count.But among in the nature distribute of plant of Shanghai,the trees for about 39 kinds,are only 4.1% of the total amount.The bushes are 85 kinds in total, for 23.5% of the total amount, including the evergreen is 38 kinds and deciduous is 47, which are very abundant in category.Rattan and water or the marsh plant are for 16 kinds,15 and 14, which are comparely less in category.(3)The Shannon-Weiner analysis of the different plant-communities types. In the Shannon-Weiner analysis on the road, the more early period of constructing is higher than the more later. There are singler in the tree category and less in the quantity on the living green area, that is probably relevant with the scale of smaller living area; the tree and living environments always exist the contradiction. The more early period of constructing is higher than the more later in the Shannon-Weiner;Among the early period of constructing parks-Changfeng park ,Zhongshan park and Zoo, for 4.5,4.25.2.8 respectively on the tree layer .The Shannon-Weiner of the different type is different, theliving area > the park > the road.(4)The structure of plant communities can be classified two types: monolayer-community pattern and multilayer-community pattern which appear to be 77%. The percentage of communities with tree-shrub-herb structure accounted is 48%, and the percentage of communities with tree-herb layer and communities with tree-shrub layer are 17% and 14%. Shrub-herb layer and Monolayer-communities' appearance frequency are both lower for 6% and17%.The results show us that multilayer-communities with tree-shrub-herb structure are the main component of Shanghai urban forest. Species belonged to the families , the tropical zone, north temperate zone and East Asia are the dominant components of Shanghai urban forest.(5)Comprehensive assessment of urbanforest in Shanghai.The indices system was established by using the methods of Stratified analysis and Delphi. Comprehensive scoring method was used in this thesis to estimate plant communities from natural degree, aesthetic degree, healthy degree, green-nearness degree and management degree. The high plant-communities of coordination degree are 67, having 16.5% of the total amount;the higher plant-communities of coordination are at most, there are 130, having 32.1% of the total amount. Evaluated to be excellent and good plant-communities are above half that show most plant-communities of center area of Shanghai to carry out the view performance and the ecosystem performances to combine effectively currently.Seeing from single-item evaluation, the healthy degree and the aesthetic degree evaluation for the excellent plant-communities are at most, having 44.4% and 28.6% of the total amount respectively.The next in order, 84.4% and 73.5% of the total amount respectively for the excellent and good.The green-nearness degree are 25.2% and 32.6%s of the total amounts for the excellent and good respectively, both in total have 60% of the total amount. The management degree for the excellent Keep less, having only 16.1% of the total amounts.Therefore, the thesis provided basic information on Shanghai urban artificial vegetation for governors according to research on plant community types, and the indices system can be used in the work of planning,management and assessment of urban forests.