Do urban ecosystem service models account for ecosystem condition and biodiversity?

Urban ecosystems provide essential ecosystem services (ES), a supply that is dependent on ecosystem condition (EC). Statistical frameworks like the UN SEEA-EA explicitly link ES flows to the extent and condition of ecosystem assets. Yet, the concrete role of EC in shaping the ES flows remains only partially understood, as their relationship is complex and varies across services. Consequently, the operational integration of EC into urban ES assessments remains fragmented. Through a systematic review of 110 eligible studies (2005-2024), we evaluated how and to what extent EC has been incorporated into urban ES assessments. For each study, we examined ES assessment methods, types of EC variables, spatial and temporal explicitness, flow types (potential vs. actual), and sustainability considerations. We found that in most studies (87%) EC variables are integrated as inputs in ES methods, particularly for regulating services. However, this integration remains limited, relying on static methods, focusing on potential over actual flows, and favoring easily measurable abiotic and structural state variables over functional, compositional, or landscape ones. While spatial explicitness is common (45%), dynamic models are a minority (20%), and assessments rarely leverage EC to evaluate ES flow sustainability. Addressing these gaps, by broadening types of EC variables, increasing temporal dynamism, and linking condition to both actual flows and sustainability, will enhance the capacity of urban ES assessments to support the planning and adaptive management of urban greening. It will also help advance the development of urban condition and service accounts, thereby increasing the relevance of urban ES assessment knowledge.