Evaluation and optimization of ecosystem services under different land use scenarios in a semiarid landscape mosaic

Ecosystem services are usually influenced by physical land use changes and climate changes. The significant land use changes and polices in Inner Mongolia mainly include urban development and the ecological restoration programs of Forest Protection, the Grain for Grass and Vegetation Recovery. This study used the Dyna-CLUE model to simulate 2030 land use changes in the Central and Western Inner Mongolia, and then explored key ecosystem services and the ESs-Balanced index under four land use scenarios with the above changes. Compared with the urban development scenario, Vegetation Recovery increases NPP, soil conservation, sand fixation, the surface and bottom soil moisture by 10.84 %, 0.76 %, 4.35 %, 1.52 % and 0.12 % respectively, but it decreases water yield by 6.56%. The Grain for Grass Program increases NPP (1.12 %), soil conservation (0.43 %) and sand fixation (3.96%) at the expense of other ecosystem services, while Forest Protection only increases NPP and the surface soil moisture narrowly. The study further provided the spatially explicit land use optimization by comparing the ESs-Balanced index under four scenarios. Vegetation Recovery suits most west and south areas covered by the sandy land or Gobi, while the Grain for Grass Program is only supportable with the western sandy farmland. The results are instructive to promote key ecosystem functions and services related to serious local ecological problems, and deal with the contradictions between ecological conservation and human development in other similar arid and semiarid regions.