The Research Of CITYgreen Software In Assessing Ecological Benefits Of Urban Forest In Changsha

Urban forest is the lung of city, is the main part of urban ecological construction, and is the important point of building a harmonious city. Urban forest has the ability of declining of air quality, photoelectric noise, serious bacteria pollution, shortage of water resource and so on. The city group which includes Changsha, Zhuzhou and Xiangtan is the experimental field of resource conservation and friendly environment social, and urban forest plays important role in constructing the two types of social. So, to study the ecological benefits of urban forest ecosystem in Changsha has important demonstration and practical significance.This article takes the Tian Jiling National Forest Park in Changsha as study object uses Arcview software and CITYgreen model, with the combined method of remote sensing imagery and field work to analyze the ecological benefits and relevant economic values of carbon storage and absorbing, air quality and stormwater runoff of Tian Jiling National Forest Park on the ecosystem scale, and analyze the ecological benefits and relevant economic values of carbon storage and absorbing, air quality of Pinus massoniana Lamb., Cinnamommum camphora, Liquidambar formosana Hance and Cunninghamia lanceolata (Lamb.) Hook, amount to 12 sample sites,2026 trees on the community scale. The results showed:1.Through field work and Arcview GIS software and CITYgreen model to digitize the study area and trees, it established the trees and land cover type database, constructed informational system of urban forest management.2.The raster data of ecosystem scale based on CITYgreen model showed that the carbon absorption and carbon sequestration rate of Tian Jiling National Forest Park was 6896.36 tons and 53.69 tons per year, respectively. The corresponding cost was saved for 1.73×1l06 yuan and 1.35×104 yuan per year, and removal quantities for O3, SO2,NO2, PM10, CO was 2331.08kg,782.24kg,1207.51kg,2162.77kg and 258.08kg respectively, and saved 2.52×105yuan per year. The peak flow was 164.63m3/s, and stormwater runoff volume of the Park Forest was 5.7×104m3, which saved 5.7×104 yuan.3.The vector data of community scale based on CITYgreen model on the Pinus massoniana Lamb., Cinnamommum camphora, Liquidambar formosana Hance and Cunninghamia lanceolata (Lamb.) Hook, amount to 12 sample sites, showed that in Pinus massoniana Lamb. community, the total economic value of removing air pollution was 1336.45 yuan, the strongest ability was Pinus massoniana Lamb. and the weakest was Melia azedarach, the single economic value was Pinus massoniana Lamb.> Liquidambar formosana Hance>Cinnamommum camphora>Melia azedarach, the total carbon storage of Pinus massoniana Lamb. was 32.27t which valued 8111.42 yuan, the carbon sequenstration was 0.74t/a which values 186.67 yuan.In Cunninghamia lanceolata (Lamb.) Hook community, the total value of removing air pollution was 948.95 yuan, the strongest ability was Symplocos caudata Wall., and the weakest ability was Sassafras tsumu, the single economic value was Symplocos caudata Wall.>Cunninghamia lanceolata (Lamb.) Hook>Cinnamommum camphora>Clerodendrum cyrtophyllum Turcz.> Sassafras tsumu. The total carbon storage of Cunninghamia lanceolata (Lamb.) Hook was 10.74t which valued 2700.04 yuan, the carbon sequenstration was 0.24t/a which valued 59.13 yuan.In Cinnamommum camphora community, the total value of removing air pollution was 464.91 yuan, the strongest ability was Pinus elliottii, the weakest ability of removing O3,SO2,PM10 was Schima Superba, of wich removing NO2,CO was Clerodendrum cyrtophyllum Turcz., and the single economic value was Pinus elliottii> Cinnamommum camphora>> Liquidambar formosana Hance> Paulownia fortunei> Symplocos caudata Wall.> Aphananthe aspera (Thunb.) Planch.> Elaeocarpus sylvestris (Lour.) Poir.> Clerodendrum cyrtophyllum Turcz.> Magnolia grandiflora> Schima Superba. The total carbon storage of Cinnamommum camphora was 8.28t which valued 2081.59 yuan, the carbon sequenstration was 0.05t/a which valued 11.31 yuan.In Liquidambar formosana Hance community, the total value of removing air pollution was 809.69 yuan, the strongest ability was Schima Superba, the weakest was Clerodendrum cyrtophyllum Turcz, and the single economic value was Schima Superba> Castanopsis sclerophylla (Lindl.) Schott.> Liquidambar formosana Hance>Cinnamommum camphora> Symplocos caudata Wall.> Cyclobalanopsis glauca (Thunb.) Oerst> Clerodendrum cyrtophyllum Turcz. The total carbon storage of Liquidambar formosana Hance was 7.83t which valued 1967.41 yuan, the carbon sequenstration was 0.06t/a which valued 14.51 yuan.4.It compared the economic values of removing air pollution of the same species in different communities. The single Cinnamommum camphora economic values of removing air pollution were Cunninghamia lanceolata (Lamb.) Hook community> Cinnamommum camphora community> Liquidambar formosana Hance community> Pinus massoniana Lamb. community, the single Liquidambar formosana Hance was Pinus massoniana Lamb. community> Cinnamommum camphora community> Liquidambar formosana Hance community, the single Symplocos caudata Wall. was Cunninghamia lanceolata (Lamb.) Hook community> Cinnamommum camphora community> Liquidambar formosana Hance community, the Clerodendrum cyrtophyllum Turcz. was Cunninghamia lanceolata (Lamb.) Hook community> Cinnamommum camphora community> Liquidambar formosana Hance community.5.Using the CITYgreen model to analyze the four trees ecological benefits of carbon storage and absorbing and air quality of four species, the results showed that Pinus massoniana Lamb.> Cunninghamia lanceolata (Lamb.) Hook> Cinnamommum camphora> Liquidambar formosana Hanc.