A comprehensive framework for quantifying ecosystem service flow focusing on social-ecological processes

Ecosystem service flow refers to the whole process of ecosystem service production, delivery and utilization, which is closely related to social-ecological processes. However, quantifying the entire ecosystem service flow process remains challenging, placing limits on the management of social-ecological systems to improve human wellbeing. Here, we explored the relationship between social-ecological processes (e.g., product transfer, matter cycling, energy flow and information delivery) and the spatial flow of ecosystem service. Then, we reviewed methods quantifying the spatial flow of ecosystem service. Finally, we proposed a comprehensive framework for quantifying the whole process of ecosystem service flow in terms of social-ecological processes. The framework consists of the quantification of ecosystem service supply and demand, the spatial flow of ecosystem service between suppliers and consumers, and the quantification of utilized ecosystem service. To better quantify the whole process of ecosystem service flow, we need to further understand the factors impacting ecosystem service flow, develop process-based models integrating beneficiaries and infrastructure, and establish social-ecological approaches to inform ecosystem service flow governance.