Requirements for the selection of ecosystem service indicators - The case of MAES indicators

Although the concept of ecosystem services (ES) has thrived over the last ten years, its operationalization is still in its infancy. A major challenge in operationalizing ES is the selection of scientifically defensible, policy relevant and widely accepted indicators. Here we examine how conceptualizations of ES influence indicator selection, and what criteria (such as validity and relevance to a policy issue) are applied in this process. We analyze how the ES concept is framed in the "Mapping and Assessment of Ecosystems and their Services" (MAES) working group and which indicator selection criteria are used in this project. Our findings indicate that there is still room for improvement in the selection of ES indicators, especially with regard to specific criteria (e.g. validity), and for linking indicators to policy issues.