Accounting of surface soil carbon storage and response to land use change based on GIS

Land use change is a main driving factor to the change of soil organic carbon (SOC) storage, in order to make a further study about the effects of land use change on SOC, based on the soil sampling data, soil type map and land use map of Jiangsu, this paper analyzed the spatial changes of the surface SOC density from 1985 to 2005 in Jiangsu and the effects of land use change on surface SOC density and SOC storage, the main conclusions are as follows: 1) The spatial changing trend of the surface SOC storage from 1985 to 2005: The changing trend in Huanghuai plain district differed too much from north to south, the Northern Yimusi plain mainly increased, while the lower reaches of Huaihe plain decreased mostly in the South; The changes in coastal beaches and ocean districts were not obvious; There presented greatly differences in Yangtze river delta plain district about SOC changes: districts covered with plain and hill along Yangtze river mainly increased, but in the Maoshanyisu hills and Taihu lake districts it both decreased. 2)The surface SOC density of different land uses all increased from 1985 to 2005, land use changes such as from cropland to woodland and grassland; grassland to woodland and construction land; construction land to cropland, woodland, grassland; wetland, construction land to other land uses can increase SOC storage, while other type of land use changes may lead to carbon emission.