Research On Plant Community Landscape Of Public Park In Changsha City

Public park is an important part of urban green space, at the same time the plant community is the basic component units of urban green space whose structure determine the plant landscape quality and the ecological function of urban green space. Construction of scientific and reasonable plant communities will make green areas development efficiently, stably and healthily, which plays a big part in protecting and glorifying environment, heightening park landscape effect and maintaining the city ecological equilibrium.Attention is concentrated on 3 representative parks in Changsha city:Martyrs Memorial Park, Dawn Park and Hunan Forest Botanical Garden. In these parks, the species composition, community type, ecological structure and species diversity of 98 relatively stable plant communities have been investigated and analyzed.The specific results are as follows:1. Changsha city parks have abundant species and rich in local vegetation which compared to its final total are extremely low. Changsha city parks have 122 woody plants, respectively belonging to 48 familia and 84 genuses in 98 plots which are accounted for 45.86 percent in existing plant species of Changsha region. There are 75 local plants belonging to Hunan, which is about 61.5 percent in all species of investigative range. In arbor layer native plants have large proportion taking 77.4 percent and in ground layer exotic plants and cultivated plants have higher proportion.2. Varied in multiple types, plant communities in Changsha city parks have a kind of zone characteristics but transitional vegetation types have obvious advantage. There are 5 community types in sample communities and the transition vegetation type-evergreen-defoliation broadleaf forest is distinct, taking 29.59 percent in all types. The zone vegetation type-evergreen broadleaf forest taking 18.37 percent in the total communities.3. The amounts of constructive species and dominant species are rich in Changsha public parks, but most of them are not widely used. Whether in the arbor layer or shrub layer, the species with highly use frequency are just only concentrated on a few species.4. The structure of plant communities is multiple structure combined with arbor, shrub and herbaceous on the whole in communities of Changsha city parks. The species density of shrub layer is denser than the arbor layer in the communities. The plots that evergreen trees are dominant in importance value occupy 65.89 percent and 75.61 percent in the arbor layer and shrub layer respectively.5. There is no regularity on species diversity distribution in different parks of Changsha city. In the different layer of plots community, the richness index and Simpson index:arbor layer>shrub layer>herbaceous layer; Shannon-Wiener index:arbor layer> herbaceous layer>shrub layer; Pielou index:herbaceous layer>shrub layer>arbor layer; The species diversity index has obvious discrepancy by reason of difference in park function and conservation and management measures.6. The result of comprehensive evaluation showed the communities withâ… -grade landscape quality take 7 percent in all appraisal communities, meanwhile, the overall plant community are in the middle level and high-quality plant landscape are relatively few.7. There are some approaches of optimizing the structure of city park greenbelt including enriching the existing plant species, increasing the diversity of ornamental plants, expanding the application of local vegetation. At the same time, referring toâ… -grade community, the ratio of trees and shrubs, evergreen and defoliation can be regulated. Attention should be both paid to the biodiversity protection and plant community landscape design properly.