A theoretical rethinking of ecosystem services from the perspective of social-ecological system

Ecosystem service (ES) research has grown rapidly, but emergent concepts such as disservices, supply-demand, relationships, and flows remain fragmented. An increasing consensus emphasizes that ecosystems cannot deliver services without human inputs, positioning ES as coproducts of coupled social-ecological systems (SES). This necessitates a theoretical rethinking of ES concepts from an SES perspective to advance comprehensive ES science. Through the SES lens, ES quantity and value are redefined as interactions between ecosystem supply and human demand. ES relationships are clarified by distinguishing inherent bundle characteristics from SES-level equilibria, which underpin cross-system flows. The framework integrates these advances by grounding ES in human-ecosystem interdependence, linking supply-demand dynamics to ES realization, resolving ambiguities in relationships through equilibrium analysis, and framing flows as outcomes of SES equilibria. By unifying these concepts, the framework addresses current inconsistencies and charts future research priorities: optimizing supply-demand balance, analyzing SES equilibria mechanisms, and modeling cross-system flow pathways.