Carbon sequestration potential of the stands under the Grain for Green Program in Yunnan Province, China

The carbon sequestration potential in living biomass and soil organic matter under the Grain for Green Program (GGP) in Yunnan Province, one of the most important target provinces of the GGP in China, was estimated in this paper using empirical curves and factors. The area of tree species planted during 2000–2007 was collected, and four scenarios for the annual area of GGP-stands to be planted during 2008–2010 and harvest options were schemed. Empirical growth curves for different tree species were developed based on data about the growth of existing plantation in Yunnan Province from National Forestry Inventory, and were used for the estimation of the carbon stocks in the tree biomass pools by incorporating with basic wood density, biomass expansion factors and carbon fraction. Empirical factors were introduced to estimate the stock change in soil organic carbon (SOC) under the GGP. The results show that the carbon stock in the GGP-stands in Yunnan Province will increase by 12.474–12.608 TgC, 33.016–35.161 TgC, 38.119–47.100 TgC, 43.057–53.626 TgC and 49.918–56.621 by the year 2010, 2020, 2030, 2040 and 2050, respectively. The annual carbon stock change in the GGP-stands will peak at 2.342–2.536 TgC per year in 2013, followed by a gradual decrease. The estimated potential carbon sequestration by GGP-stands amounts to 10.82–12.27% of the carbon stocks of forest ecosystems in Yunnan province in the 1990s.