8Watson R T, Noble I R, Bolin B, et al. Land use, land use change and forestry: a special report o{ the Interg- overnmental Panel on Climate Change[M]. Cambridge UK.. Cambridge University Press,2000.
9Lal R. Soil carbon dynamics in cropland and rangeland [J]. Environmental pollution, 2002,116 (3) : 353-362.
10West T O, Marland G. A synthesis of carbon sequestra tion, carbon emissions, and net carbon flux in agriculture comparing tillage practices in the United States[J]. Agricul ture, Ecosystems g> Environment,2002,91(1) :217-232.
