Response of ecosystem service flows to the ecological restoration project of Loess Plateau in northern Shaanxi Province

Abstract: Clarifying the complex dynamics of ecosystem service (ES) flows and identifying the key locations of the ecosystem service supply-demand chain is crucial for achieving sustainable management of ecosystem services. However, the understanding of how ES flows respond in ecological restoration projects is in urgent need of deepening. Taking the Loess Plateau in Northern Shaanxi, China as an example, this study quantitatively analyzed the effects of the Grain-for-Green Program, the world's largest vegetation restoration project, and the check-dam construction, the key soil and water conservation project.

       The results show that between 2000 and 2020, compared to the sum of the benefits generated by the two projects implemented separately, the inter-regional ES flows in the areas where these two projects were jointly implemented increased significantly (p<0.01) in terms of carbon sequestration, water source conservation, flood regulation, and soil water retention. The ES carbon flow increased year by year and then tended to stabilize, while the ES water flow showed a fluctuating downward trend with the increase of years, the trend degree of water flow rate change is -1.33×10³ m³/(km²·a). The impact of different projects showed spatial heterogeneity across the entire region, with a significant increase in regional ES flows observed in the western areas. Quantitative analysis indicated that when the Grain-for-Green Program and silt dam construction were jointly implemented, the regional ES flows of all services were higher, and the synergistic fields were more extensive. The research results can provide references for the ecological protection and restoration of the Loess Plateau region.

Keywords: Ecosystem Service Flows; Ecological Restoration; Soil and Water Conservation; Supply and Demand