Ecosystem services assessment from capacity to flow: A review

Ecosystem services are the basis for human survival and development and act as a bridge between nature and society. In recent years, ecosystem service flows have become the focus and primary challenge of ecosystem service research, with development in research efforts toward quantification and spatialization. This review explains the necessity of ecosystem service flows, discusses the progress of research in this area over the last decade, and compares the theoretical and representative research approaches from two conceptual perspectives on ecosystem service flows. One of these approaches focuses on processes, treating ecosystem service flows as the spatiotemporal association between ecological service provision areas and service benefit areas, and the other emphasizes final utility, considering ecosystem service flows as the actual supply of ecosystem services to beneficiaries in different areas. On this basis, the research gaps in theoretical principles, assessment methods, and applications are summarized, and future research perspectives on ecosystem service flows are proposed, with a focus on optimizing ecosystem service benefits and promoting cooperative development of systemic human–nature relationships.