variations in ecosystem service value in response to land use changes in the loess plateau in northern shaanxi province, china

in this paper, we report an investigation of changes in land use and ecosystem services on loess plateau in northern shaanxi province from 1978 to 2004. we used three landsat tm and/or etm data sets to estimate changes in the size of five land-cover/land-use categories, and we also used previously published value coefficients to estimate changes in the value of ecosystem services delivered by eachland category. finally, we ranked the contribution of various ecosystem functions to the overall value of the ecosystem services. we have estimated that the annual value of the ecosystem services is 56.95 billon rmb in the loess plateau in northern shaanxi province in 2004. in the loess plateau in northern shaanxi province, from 1978 to 2004, the economic value of the fixing carbon are higher, the economic value of water conservation are lowest, but the economic value of the npp, fixing carbon and supplying oxygen account for total value above the ninety percent, obviously the vegetation own created the biggest ecosystem service value.we conclude that future land-use policy formulation should give precedence to the conservation of these ecosystems over uncontrolled reclamation, and that further land reclamation should be based on rigorous environmental impact analyses.