Considerable efforts are made to integrate ecosystem services (ES) indicators into spatial planning practice. Although a lot of decision support systems already provide helpful functionalities, they are not yet integrated into everyday decision-making, mainly because they do not readily fit into planning processes in practice. There is an increasing awareness that the development should foster collaboration between interdisciplinary researchers and the end users of the tools to secure their suitability for such planning processes. Hence, user-oriented research and experimenting is seen as the appropriate approach for getting the tools ready for practice. Guidelines for conducting such processes are yet missing. Here, we contribute to the development of such guidelines by means of a practical case study. The focus is placed on how transdisciplinary (TD) research on spatial decision support systems should be designed for the integration of ES indicators into planning practice. In a TD project, a web-based visualization platform with indicators of relevant ES was developed to support municipalities of the Canton of Zurich, Switzerland, in assigning adequate watercourse corridors according to the revised Swiss Waters Protection Act. A preliminary as well as an enhanced version of the platform prototype were demonstrated to different actors for evaluating the platform's readiness for practice. We assessed the process design and the quality of the product in a discursive manner. Thereby, we implemented a set of assessment criteria derived from literature and adapted them to the case study at hand for the analysis of empirical material (participant lists, project schedule, meeting minutes and observation protocols). Finally, we discussed the lessons learned on developing significant ES indicators and their visualization and the conclusions drawn with respect to ensuring the quality of the platform development process. The results show that conceptualizing the ES indicators in strong collaboration with practice representatives increased their relevance to the actors' needs and therefore their legitimacy. Providing interfaces for collaboratively translating practical approaches into scientific models is, thus, crucial for the development of significant indicators. Furthermore, specifying the purpose of the visualization platform in planning processes requires prototyping and iterative conceptualization, because practice actors need concrete examples to express their specific demands. This also requires that the concept of developing the ES indicators and the spatial decision support systems should be treated rather as an open working paper than as a final document agreed on in the first collaboration phase. Hence, time scheduling and occupying skilled project managers for this iterative process should be taken seriously. (C) 2015 Elsevier Ltd. All rights reserved.
