Abstract: In order to understand the carbon sequestration of ecological forests in Loess Plateau, a comparative study was made on the organic carbon density (OCD) of soil, litter, and plant organs in an 8-year-old Robinia pseudoacacia plantation and nearby barren land. Comparing with the barren land, the young R. pseudoacacia plantation had a decrease (0.26 kg·m^-2) of soil OCD, but the OCD in its litter, root system, and aboveground organs increased by 121.1%, 202.0%, and 656.7%, respectively, with a total carbon sequestration increased by 3.3% annually, which illustrated that R. pseudoacacia afforestation on Loess Plateau had an obvious positive effect on carbon sequestration.

Key words: C sequestration, ecosystem, Robinia pseudoacacia plantation, Loess Plateau, tobacco field, soil nutrient, spatial variability, management zone.