Ecological Evaluation And Optimization Strategy For The Green Space In Chongqing Metropolitan

This paper has researched landscape species in the parks, residential area and theroadside green space of Chongqing metropolitan. The species composition, life-formand origination of landscape species in Chongqing metropolitan were analyzed,expecting to analysis the time evolution and the different rank of green space in twoaspects. The species diversity and different configuration of landscape species indifferent time were compared, and different area park, different types of residential area,different ranks of roadside green space were compared too, to make the ecologicalevaluation and give the optimization strategy at the same time. Useful suggestions forthe planning of green space and the protection of biodiversity are gaved. The mainconclusions of this study are below.â‘ The landscape species in Chongqing metropolitan were recorded in200,belonging to74families140genus. The distribution of Family, genus and species has ahuge difference. The single species and the single genus hold a big propotion, and theguarantee of urban species diversity be at a disadvantage. The number of tree,shrub,vineand bamboo species are107,74,9,10. The ratio of tree species and shrub species is1.4:1. The number of evergreen tree and deciduous tree are101,80, and the ratio is1.3:1.The number of native species is126, and74of alien species. Alien species occupies37%proportion in the total number of landscape species. Alien species occupies a highproportion in green space of Chongqing metropolitan, is not conducive to the formationfor the regional characteristics of chongqing about urban landscape.â‘¡In different periods, the configuration of landscape species existed certaindifferences in Chongqing metropolitan. The number of landscape species is189in thegreen space before2000, compared with the green space before2000, the proportion ofshrub species has reduced in the green space after2000, and the deciduous species hasincreased. Though the proportion of alien species has reduced in green space after2000,has a high proportion.â‘¢The landscape species in park green space has recorded in178,150to theresidential area, and64to the roadside green space. The species of roadside green spaceis not rich enough, and the configuration is poor as well. No obvious law is foundbetween the parks with different area. So the main factor influencing speciesdistributions is man-made. For different types of residential area, the high-grade has the most species, but the old residential area has the least. The different form of roadsidegreen space is single, and the diversity of vertical structure is poor. At the same, thespecies and configuration of the roadside trees is monotone. In general, the evergreentree is lack in three types of Chongqing metropolitan, alien species has a highproportion in the three types of green space.â‘£In this survey, rare species (frequency less than10%) which contains about107kinds has a proportion about59.1%in the applied frequency. At the same time, thecharacteristic is rich for the ornamental species.The florescence of flower ornamentalsmain distributes in spring season,and in autumn for fruit ornamentals. In this survey,only9kinds of vine species,with a low frequency, are recorded, so we should pay moreattention on the application of the native vine species in urban green space.