Impacts of Land Use Change on the Vegetation Carbon Storage in the Region around Taihu Lake, China

Land use/cover change is the main drive factor for the change of ecosystem carbon storage. To understand and appraise the carbon source/sink function of terrestrial ecosystem accurately, it needs to evaluate the impact of land use changes on carbon storage firstly. Based on data from remote sensing TM imageries in 1980, 1990 and 2005 in the region around Taihu Lake in China, the process of land use/cover change which divides to cropland, forest land, wetlands, grassland, settlements and other land had been explained, then the conversion matrix of land use change had been analyzed by GIS technology. Under the above, the paper calculates the change value of vegetation carbon storage in this area which caused by land use change with the method supplied by the 2006 IPCC Guidelines for National Greenhouse Gas Inventories. The main results as follows: (1) The area of cropland, forestland and grassland had decreased by 223.26km(2), 1,182.50km(2) and 178.90km(2) during 1980-1990, and the cropland had translated out to forest land and settlements mainly, the land types transferred into cropland includes forest land, grassland and other land, among which 1,463.90km(2) of forest land was transferred into cropland. The area of grassland had increased by 1,270.47km(2), adversely, the cropland and forest land had decreased by 5,929.51km(2) and 1381.94km(2) during 1990-2005, and the transferring-out object of cropland includes wetlands, forest land, grassland, settlements and other land, with only 59.95% of the original cropland remain unchanged. (2) The vegetation carbon storage had decreased by 642,171.27Mg because of land use change during 1980-1990, and the transferring from forest land to cropland has caused a decrease of 775,867Mg in vegetation carbon storage, that from cropland to forest land has caused a increase of 113,261.43Mg, that from grassland to cropland has caused a increase of 8,129.36Mg, and that from grassland to forest land has caused a increase of 12,304.94Mg; The vegetation carbon storage had decreased by 683,125.18Mg during 1990-2005, and the transferring from forest land to cropland has caused a decrease of 285,034Mg, that from forest land to grassland has caused a decrease of 417,617.73Mg, that from cropland to grassland has caused a decrease of 40,938.65Mg, while that from cropland and grassland to forest land has caused a respective increase of 52,856.61Mg and 7,608.59Mg. (3) The results of vegetation carbon storage change which calculated by the IPCC method had some errors in number value to other domestic research results, so the paper suggests the government of China should compile the greenhouse gas inventories which accord with it's own situation.