The potential of participatory citizen science for assessing ecosystem services in support of multi-level decision-making – Insights from Switzerland

The importance of forests for the provision of ecosystem services is uncontested. Monitoring these services' availability is a key process to discuss sustainability, planning and management measures and provide information for decision-making at different policy levels. Particularly forests close to or in urban areas are predominately intensively used by various stakeholder groups, who benefit from the provided services. The development of an assessment tool to track the ecosystems' key variables would help to secure the sustainable provision of most ecosystem services according to the needs of the local users, improve the data basis for decision-making processes and allow comparisons between different forests. Recreational forest visitors could support the data collection process through, e.g., citizen science approaches. Thus, this study aims to investigate how citizen science has been applied to assess forest ecosystem services so far and based on this information, collect professionals' opinions and attitudes regarding society's participative integration in ecosystem services' assessment and monitoring. To reach these research objectives, an exploratory literature review (53 documents for final analysis) and eighteen semi-structured interviews with practitioners from different fields, e.g., nature conservation and education, were conducted. This research reveals that society's active integration in forest ecosystem services' assessment and monitoring would foster the transition to more sustainable and healthier forests and ecosystem services and raise society's awareness of the importance and maintenance of forests. Additionally, this would create a data basis for decision-making on regional planning and policy levels that represents and combines opinions and voices of experts and society. • Participation could raise public awareness of forest ecosystem services (FES). • Citizen science is a suitable tool for assessing and monitoring certain FES. • Experts support involving the public in assessing some FES.