dynamics of ecosystem service value caused by land use changes in manas river of xinjiang, china

this study aims to quantify the impacts of land use changes on ecosystem service value during large scale land development, and to provide key information for both economic development and policy makers for eco-environmental protection. the study area locates in manas river watershed which is a typical land development region in northwest china. landsat mss/tm/etm+ images in 1976, 1989, 1999 and 2008 were applied to estimate ecosystem service value based on land use, and subsequently ecosystem service value dynamics were analyzed in response to land use changes. it is found that the built-up area and cultivated land increased significantly from 1976 to 2008. the decreasing ecosystem service value (from 17362.2 million yuan in 1976 to 16975.0 million yuan in 2008) is mainly caused by the reduced grassland. the combined ecosystem service value of water body and grassland is over 60% of the total value. functions of water supply, waste treatment, soil formation and retention and biodiversity protection contributed to over 70% of the total service value. the results suggest that a reasonable land use plan should emphasize protection of water body, woodland and grassland as they have the highest ecosystem service value.