The large-scale and cross-regional payment for ecosystem services (PES) contributes positively to ecology-economy balance and thus helps prevent environmental challenges such as "sand storm". However, existing PES programs often overlook the connection between service-providing areas (SPAs) and service-benefiting areas (SBAs). Here, we developed an interregional PES framework based on the theory of ecosystem services flow and applied it to the largest Chinese grassland nature reserve, Xilingol Prairie, to quantitatively identify SPAs, SBAs, and flow paths of the ecosystem wind erosion prevention service (WEPS). We showed that, from 2000 to 2020, the grassland ecosystem of Xilingol Prairie had brought an annual WEPS benefit of 1.21 × 108 t/a and economic value of 12.44 × 108 CNY/a, accounting for approximately 107.71% of the GDP in the same area and year and with a slightly increasing trend in most areas. We reveal obvious seasonal (over half in the spring) and interannual variations in the benefit and that Inner Mongolia, Hebei, and Northeast China are the most important beneficiaries of WEPS, rather than Beijing and Tianjin as traditionally thought. Our results warn that the WEPS supply capacity will not last long and call for finer spatial (e.g., among cities) and temporal (e.g., focus on the spring) resolution for PES policy design.
Keywords: HYSPLIT model; ecosystem services flow; grassland nature reserve; payment for ecosystem services; wind erosion prevention service.