Review of Multicriteria Methodologies and Tools for the Evaluation of the Provision of Ecosystem Services

An ecosystem is defined as an area, place or environment where organisms interact with the physical and chemical environment. Ecosystems provide a variety of benefits to people that are divided into market and non-market ecosystem goods or ecosystem services (ES) and classified in multiple ways. A wide range of methodologies is available to value changes in ES. The type of valuation technique chosen depends on the type of ES to be valued, as well as the quantity and quality of data available. Since ES provide multiple benefits, they are valued for a range of reasons and researchers must employ valuation methods that better match this diversity. How to compare objects with multiple characteristics has been the focus of Multi-Criteria Decision Analysis (MCDA). In this paper, a literature review has been performed that covers an overview of various methodologies that seek to improve the knowledge base of existing tools and methodologies in ES evaluation. The focus will be on studies that used MCDA for an ES assessment; attempting to cover a representative sample of case studies of ES assessments through MCDA. We also discuss advantages and disadvantages of different methodological choices in ecosystem service evaluation. We conclude that the ES concept is currently used in a range of studies with widely differing aims creating difficulties for policy makers as well as researchers since it makes it difficult to assess the credibility of assessment results. MCDA techniques can indeed help structuring the problem and supporting a more transparent decision-making.