Citizen science for forest ecosystem services assessment–Insights from co-creation in Switzerland

Forests play a critical role in climate regulation by storing carbon and delivering a wide range of ecosystem services. Sustainable forest management is essential to maintain these services, however current monitoring and assessments frameworks tend to prioritize easily measurable and economically relevant forest ecosystem services, often neglecting cultural and locally relevant aspects. In Switzerland, for example, data gaps and low temporal resolution of existing monitoring systems limit site-specific, local decision-making and a holistic ecosystem service assessment. Citizen science offers a promising approach to address these gaps by engaging diverse forest users in the assessment and monitoring of local forest ecosystem services. Building on existing studies, we aim to (i) identify which forest ecosystem services can be effectively assessed through citizen science and (ii) develop a guiding framework for systematic and efficient data collection. Thus, we conducted three co-creation workshops with eleven forest professionals, complemented by additional expert consultations. Our results indicate that cultural services show the highest suitability for assessment with the support of citizen scientists. For certain regulating and provisioning services, monitoring data already exists (e.g., protective forests), whereas others require expert knowledge and modelling (e.g., oxygen production), making citizen science involvement less appropriate. These findings highlight the importance of (i) identifying locally relevant ecosystem services, (ii) reviewing existing data sources, (iii) defining appropriate indicators, and (iv) designing data collection and evaluation procedures prior to involving citizen scientists. Overall, our research contributes to the integration of cultural and locally relevant forest ecosystem services into sustainable forest management through citizen science and provides guidance for forest-related policymakers to promote participatory and future-oriented decision-making.