Understanding the contribution of ecosystem services to urban metabolism assessments: An integrated framework

The growing evidence-base demonstrating that cities are responsible for accelerated natural-resource erosion and the exacerbated impacts of atmospheric emissions on climate change suggest the need for more systemic resource-use mitigation strategies at the urban scale. Nowadays, ecosystem service analysis provides an extensive reservoir of techniques and strategies to optimize the metabolism of cities through enhanced resource cycling and emission abatement. However, this reservoir is largely untapped in urban metabolism research despite substantial progress in ecosystem service knowledge and classification. In response to this knowledge gap, in this article we propose an integrated urban metabolism and ecosystem service framework to extend Economy-Wide Material Flow Analysis (EW-MFA). The framework utilizes "Pressures", "Drivers" and "State" indicators to describe the relationships between anthropogenic and natural systems. A set of indicators was compiled from previous urban metabolism and ecosystem service studies to provide a shared and adaptable set of assessment categories across the two areas to jointly measure ecosystem services and resource flows. Through the proposed framework, interdependencies and causal relationships between ecosystem service assessment and EW-MFA flow categories can be identified. The focus of the paper is on elaborating the conceptual foundations of the framework and its analytical characteristics.