Vegetation Restoration And Its Impact On Ecosystem Services In Mu Us Sandy Land

Combating desertification is critical to China's protection of natural resources and sustainable development,but the fragile ecological environment and accelerated human activities have greatly increased the overall difficulty.In order to mitigate the impact of environmental degradation,China has spent a lot of time,money and manpower on a series of large-scale ecological protection projects.Therefore,the systematic investigation and long-term monitoring of the vegetation after the project implementation,and the assessment of its vegetation restoration and its impact on the corresponding ecosystem services are of great significance for the evaluation and guidance of ecological engineering.This paper aims to reveal the change of vegetation after the implementation of large-scale ecological engineering in Mu Us Sandy Land by using the method of land cover change and NDVI change trend analysis,further explore the impact of vegetation change on ecosystem services,and carry out the research on the coordination and trade-off relationship of ecosystem services.It is expected to provide decisionmaking basis for ecosystem service management,and provide scientific and reasonable reference for future vegetation ecosystem restoration Mu Us Sandy Land and even other areas.The main conclusions are as follows:(1)After 2000,vegetation recovery was obvious in Mu Us sandy land,and NDVI showed an overall upward trend.The area covered by the area with a significant increase(P < 0.05)reached 67.73%,while the area occupied by the area with a significant decrease(P < 0.05)was very small,only 0.23%.In terms of land use change,the expansion of construction land is serious,which is mainly caused by the transfer of grassland,cultivated land,water area and wetland;in terms of area change and change intensity,grassland is the main land type of sand transfer.(2)Most of the places where NDVI changes significantly occur in the areas without land conversion,and the increase of NDVI is mainly due to the improvement of vegetation in sandy land,low-coverage grassland,cultivated land and medium coverage grassland,and the second is due to the mutual transformation between cultivated land and low coverage grassland.A small part of the decline in NDVI was due to the deterioration of vegetation between sandy land,cultivated land and low-coverage grassland,and shifting of cultivated land,sandy land and high-coverage grassland to construction land.(3)The six ecosystem services quantified in this paper: grain yield,meat supply,water production service,carbon sequestration service(NPP),soil conservation and forest leisure show different characteristics of time and space.(4)There is a stable trade-off relationship between water production services and soil conservation services;food production and all services except water production services show a synergistic relationship;NPP and soil conservation services have always shown a good synergy;the forest recreation in cultural services and the three supply services(water production services,food production and meat supply)have shown a stable synergy relationship;the interaction between ecosystem services from 2000 to 2015 has a strong similarity,which is not clear Manifest change.(5)Mu Us Sandy Land is divided into four ecological functional areas,and corresponding management suggestions are put forward.Among them,"high delivery area of ecosystem service" should pay attention to the establishment of ecological agriculture and animal husbandry development mode;"soil erosion area of middle sandy land" should pay attention to the management of sandy land and improve the ability of soil conservation;"low delivery area of ecosystem service" should emphasize the combination of ecological balance protection,rational management and full development and utilization of grassland;"high vegetation restoration area" should give full consideration to the shortage of water resources,avoid overexploitation of groundwater resources to achieve the sustainable development of the economy and society in the sand area.Vegetation restoration directly affects the interaction between the ecosystem services,and further affects the changes in ecological function zoning.With the restoration of vegetation,other areas are gradually transformed into "high vegetation restoration area".