Abstract: Danjiangkou Reservoir is the water source of the middle route of the South to North Water Transfer Project. The change of water level caused by the heightening of reservoir dam has profound impacts on ecosystem function in the water-level-fluctuating zone of the reservoir area. In this study, we collected soil samples under different land use types in the new water-level-fluctuating zone before and after flooding, and examined the effects of flooding on soil nutrients. The results showed that flooding affected soil nutrient contents of different land use types across different elevations in the new water-level-fluctuating zone. Before flooding, soil comprehensive nutrient index of different land use types belonged to levels I and II, with an order of abandoned farmland area > natural restoration area > arbor area > shrub area > farmland area. After flooding, soil comprehensive nutrient index increased to levels II and III. The arbor area had the highest value, followed by shrub area, farmland area, natural restoration area, and abandoned farmland area. The spatial distribution of soil comprehensive nutrient index indicated that elevation and land use types affected soil quality in the new water-level-fluctuating zone. The artificial vegetation restoration based on nature is beneficial to the rapid restoration of ecological function of the new water-level-fluctuating zone and the safety of water quality in the reservoir area.

Key words: water-level-fluctuating zone, Danjiang River wetland, vegetation restoration, soil nutrient, returning farmland to wetland