Effects of land use and cover change on terrestrial carbon stocks in urbanized areas: a study from Changzhou, China

Land use and cover change is the key factor affecting terrestrial carbon stocks and their dynamics not only in regional ecosystems but also in urbanized areas. Using the typical fast-growing city of Changzhou, China as a case study, this paper explored the relationships between terrestrial carbon stocks and land cover within an urbanized area. The main objectives were to assess variation in biomass and soil carbon stocks across terrestrial land covers with different intensities of urban development, and quantify spatial distribution and dynamic variation of terrestrial carbon stocks in response to urban land use and cover change. On the basis of accurate spatial datasets derived from a series of Landsat TM images during the years 1986 to 2011 and reliable estimates of urban biomass and soil carbon stocks using the InVEST model, our results showed that carbon stocks per unit area in terrestrial land covers decreased with increasing intensity of urban development. Urban land use and cover change and sealing of the soil surface created hotspots for losses in carbon stocks. Total carbon stocks in Changzhou decreased by about 30% during the past 25 years, representing a 1.5% average annual decrease. We suggested potential policy measures to mitigate negative effects of land use and cover change on carbon stocks in urbanized areas.