Spatial Pattern Of Carbon Storage By Urban Trees In Shanghai,China

Global warming has received extensive concern on worldwide. Arguably, more than 80% of carbon dioxide emissions originate in urban areas. However, the role of human settlements in the biosphere evolution and in global carbon cycling remains largely neglected. Understanding the role of urban forest in carbon storage and global carbon cycle is crucial for estimating future trajectories of greenhouse gas concentrations in the atmosphere and can facilitate mitigation of climate change.In this study, we investigated the spatial pattern of carbon storage by urban forest in Shanghai, China. We established 4 transects radiating from the Shanghai urban core (The People’s Square) to the edge of the city. Urban forest inventory was conducted at 104 sites along the 4 transects, and each site covers at least 3 urban green spaces with an area about 400 m2. Each transect is composed of about 26 sites including 6 different land-use types (business area, residential area, educational area, park green space, arterial road, industrial zone and agricultural area).Urban forest inventory was conducted from Oct 2013 to Jan 2014. Then, the aboveground carbon storage of urban forest in Shanghai was estimated by combining the transect inventory data with remote sensing data of the high-spatial-resolution.The main conclusions are as follow:(1) Based on the urban forest inventory data from the 104 sites, the average aboveground carbon storage of urban forest in Shanghai was 25.92 t C/ha, with an decreasing in order of South Line> West Line> Northern Line> Eastern Line. Large difference in aboveground carbon storage of urban forest among different land use types, The highest vegetation carbon density occurred in green park which is 42.721 C/ha and the lowest was in the atrial traffic (18.04t C/ha). The average vegetation carbon density of all the 6 land decreasing in order of green park> educational district> commercial area> industrial zone> residential area> atrial traffic.(2)Model estimation results showed that during late 2013 to early 2014, the total aboveground carbon stocks of urban forest in the center district of Shanghai is 479344.68 t C and carbon density was 57.99 t C/ha. The aboveground carbon stocks in decreasing in order of Putuo District> Changning District> Yangpu District> HuangpuDistrict> Xuhui District> Zhabei District> Jing’an District> Hongkou District.(3)Policy orientation, major ecological greening projects such as "transplanting big trees into the city" and the World Horticultural Exposition were found to have important impact on the spatiotemporal patterns of aboveground carbon stock in Shanghai’s urban green space.