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

Abstract

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 ES supply 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 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 condition variables, spatial and temporal explicitness, flow types (potential vs. actual), and sustainability considerations. We find that integration is decisively underway, with most studies (87%) using EC variables as inputs, predominantly for regulating services. However, this integration is narrow: it relies on static methods, focuses on potential over actual flows, and favors easily measurable abiotic and structural state variables over functional, compositional, or landscape ones. While spatial explicitness is common (45%), dynamic models are rare (20%), and assessments seldom 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 ecosystem condition and service accounts, thereby increasing the relevance of urban ES assessment knowledge.