Estimate of total CO2 output from desertified sandy land in China

Soil is an important factor in regional and global carbon budgets because it serves as a reservoir of large amount of organic carbon. In our study, using remote sensing data of different periods we analyzed the development and reversion of desertification in China, calculated the variations of organic carbon contents of the desertified lands in China. The results showed that the total storage of organic carbon in 0-50 cm soil layer of the desertified lands is 855 Mt. In recent 40 yr, the total CO2 amount released by land desertification processes to the atmosphere was 150 Mt, while the CO2 amount sequestered by desertification reversing processes corresponded to 59 Mt C. Hence, the net CO2 amount released from desertified lands of China corresponded to 91 Mt C, about 68.42% of the 133 Mt C of annual CO2 release in the global temperate and frigid zones, Simultaneously, it indicated that CO2 amount sequestered by desertification reversing processes in desertified land had greater potential than the other soils. (C) 2001 Elsevier Science Ltd. All rights reserved.