| The vegetation on riparian zone is the most important part of urban green space system, called "Greenways" visually. It plays a crucial rule in improving city environment, facilitating the exchange between water and land, protecting the biodiversity, constructing beautiful landscape and so on. The functions of the riparian zone are depending on the plants, so the paper has done some researches on this point of view, in order to know the status quo and characteristics of the vegetation on riparian zone in Shanghai in order to guiding the greenization..The paper has investigated 201 sample plots among 84 rivers belong to 12 districts in Shanghai, then did some researches on their types and characteristics. On these bases, We established an approporate evaluation system by using the method of AHP. Then we evaluated the vegetation types and gave advices in constructing plants community. The conclusions are as follows:1. The plants communities can be divided into 6 groups of vegetation, 13 Vegetations and 67 Formations. The most common three types are Salix babylonolica Form of Deciduous Broad-leaved plants, Phragmites communis Form of Emerging plants and Yucca filamemtosa Form of Summer-green coniferous plants. But bamboo community and grass community are few.2.There are some rules in the distribution of vegetation types. Location and retaining wall are two factors which effect the distribution. Evergreen shrub, Deciduous shrub, Broad-leaved and coniferous mixed community and Evergreen Broad-leaved community are growing in old district; Evergreen and deciduous Broad-leaved community and grass community are growing in new district, Emerging plant community is growing in countryside; the number of vegetation types in suburb are fewer than in other district.There are more vegetation types along rigid retaining wall than that along soft retaining wall. Most of Deciduous Broad-leaved community and Evergreen shrub are growing along rigid retaining wall, Emerging plant community are always grow along soft retaining wall.3. During the investigation, 165 species which belongs to 135 genera and 70 families were detected. Gramineae is the biggest family, Rosaceae,Oleaceae Compositae,Leguminosae and Salicaceae families are also have many species. Most of them are local species and grow well, but the most widely used ones are still few, there are some species have plant diseases and insect pests detected. 4. Tree-shrub-herb structure and tree-herb structure are the two patterns of disposing which account for large percentage. Most values of species richness and biodiversity are moderate, the highest or the lowest ones are few. The values of species richness and biodiversity in old city and new city sample plots are higher than the value in suburb and countryside. The value of Broad-leaved and coniferous mixed community and Evergreen and coniferous mixed community are high, Bamboo and grass community are low.5. Seventy Two representative sample plots including all types had been evaluated, the results indicated that most of them are fitting, staying in level II orIII. The community which has many species or more local species will get high scores, Emerging plant communities also evaluated as good vegetation types in riparian zone, But the types which are bad always have simple community structure and few appropriate species6.According to the characteristics of rivers and riparian zone in Shanghai, We have done some researches in improving artificial vegetations on Shanghai riparian zone to make them adapted to the location, function and retaining wall of the river, so they can be brought into play its ecological fuctions.
|
PDF Full Text Request