Ecosystem services modeling in the changing landscapes

Ecosystem sevices are the benfits people obtain from ecosystems. The ecosystem sevieces of 60% are degradation in the world. The one of major challenes facing the worlds people are meeting the needs of people today and in the future, and sustaining atmosphere , water, soil and biological products which provieded by ecosvstems the loess plateau of china, an area suffered from severe soil erosion in the world was the study area. the changes of the relationships between and trade off were analysed. based on the understanding of the relationships between ecosystem processes and services at multiple scales we develop an integrated ecosystem service assessment system. it is a spatially explicit assessment and optimization tool for regional ecosystem sevices, including dateabase compilation, ecosystem services assessmentm scenario analysis, tradeoff analsis and integrated optimization. the changes in four key ecosystem services including water regulation, chineses governments implementation of the grain to green program GTGP we find that significant coversions of farmland to woodland and grassland have resulted in enhanced soil conservation and carbon sequstration. however the water yield of region is decrease and the climate becoming warmer and drier. the total grain production increased in spite of a significant decline in farmland acreage, resulting in improved overall socioeconomic conditionsconditions in the region. these seemingly contradictory relations have been attriuted to the strong socieconomic incentives embedded in the ecological rehabilitation policy should be adopted, with a focus on the dynamic interactions between people and their environments in a changing world.