Research On The Plant Diversity For Green Space System In The Main Urban Areas Of Chengdu City Based On The 3S Technology

China’s biodiversity is one of the particularly rich countries in the world,but per capita resources especially less,so the biodiversity has great significance to the production and living in China.And city as a special artificial systems,plant diversity in the area affected by man-made factors interference is stronger,and the development of the city constantly strengthened the stress on plant diversity,community was badly damaged by habitat and the situation is very serious..Therefore,this article using the 3S technology and based on field survey data of plant communities of the main area in Chengdu.using the principle and method of landscape ecology and the analysis method of biodiversity,then analyzes the influence and change of the plant diversity by the urbanization in the main city,and reveals the change rules of the green space landscape pattern and plant diversity under the influence of urbanization in the main city.The following conclusions:(1)From the result of land Type,the second is the green landscape,accounting for 22.2%of the total type;agricultural land is the largest amount of land use conversion in 15 years,it reduced 87.86 percent,and mainly in the urban-rural fringe area around the Third-ring Road.The main types of agricultural land transformed into construction land and artificial green space.(2)From the point of landscape features,overall of landscape fragmentation is abate,SHDI landscape diversity decreased;From each landscape type,green landscape fragmentation is the largest,and plaque is the most complex,PD value reached 4.71/hm2 in 2014,and lower than in 2000,shows that green landscape connectivity become better,and ecological function enhanced.(3)From the point of green plant community species diversity,there are 85 families,186 genera,264 kinds,including herbaceous species(102 species)>arbor species(89 species)>shrub species(73 species);species number of different circles is uneven distribution,the number of types of third ring road>second ring road>first ring road.(4)From the point of plant diversity index changes,the plant diversity of green space landscape shows that herb>arbor>shrub;the plant diversity among various spheres shows that third ring road>second ring road>first ring road.arbor species and shrub species diversity is higher in the Northwest of Jinniu district and Qingyang district and the southeastern of jinjiang district in,the diversity of herb.is higher in the northeast of Chenghua district.(5)the impact of urbanization on plant biodiversity mainly changes in landscape pattern,a large number of the introduction of exotic plant species for cultivation and the structure of ecological communities.where the Urbanization is higher,the distribution of native species is less,whereas higher.Statistical result show that the distribution of native species in Chenghua is best,but exotic species is less.