The Evaluation Of Ecosystem Services Provided By Urban Forest Based On CITYgreen

With the acceleration of urban development, the ecological problems become more and more servere. With the proposed strategy of sustainable development, the public awareness of forest ecosystems is also deepening and people gradually acknowledge the importance of the urban forest ecosystem. In this paper, we studied the significance of the urban forest ecosystem services based on the evaluation of ecosystem services provided by the Purple Mountain forest in Nanjing. Quantitative evaluation of urban forest construction was discussed, and we also aimed at enhancing awareness of forest ecosystem services, understanding of urban forest planning and construction, and providing a scientific fundamental for the national "green GDP".This paper studied the evaluation of ecosystem services provided by the Purple Mountain forest of Nanjing. The results were based on the forest resource Inventory vector data of the Purple Mountain between 2002 and 2012. We have done field survey and applied the CITYgreen5.4 and ArcGIS function module of the ArcView software. The results showed that:(1)Compared with those in 2002, the tree canopy of study area in 2012 decreased 171.71 hectares. Meanwhile, farmland area, grassland area and the water area decreased 74.03, 6, 7.32 hectares respectively for the non canopy floor area. The impermeable layer increased 259.06 hectares.(2)The total amount of ozone(O3), sulfur dioxide(SO2), nitrogen dioxide(NO2), particulate matter(PM10), carbon monoxide(CO) removed by the Purple Mountain in 2002 and 2012 was 472.5t and 400.98 t respectively. The total economic value was 15.32 million yuan(2002) and 12.93 million yuan(2012), reduced 2.39 million yuan.(3)The total amount of carbon storage and carbon sequestration produced by the Purple Mountain was 363230 t in 2002, 319645 t in 2012. The total economic value in 2002 and 2012 was 44.46 million yuan and 38.35 million yuan respectively, reduced 6.10 million yuan.(4)The total amount of storm water control produced by the Purple Mountain was 5.11×106t in 2002,and 4.32×106t in 2012. The total economic value was 31.22 million yuan(2002) and 26.39 million yuan(2012), reduced 4.82 million yuan.(5)From 2002 to 2012, averagely with trees layer of the Purple Mountain reduced by every one hectare, the economic value of air pollution removal, carbon storage and carbon sequestration and stormwater runoff reduction decreased by 13961 yuan, 35552 yuan and 28114 yuan respectively.(6)Based on the results of CITYgreen model and considering modern concept of ecological civilization, we discussed the current status of urban forest construction of urban forest construction, found deficiencies of the current construction of urban forest and made planning recommendations to ensure the smooth construction of the urban forest.