Forest|Health: a pilot study on feasibility and exploratory outcomes of a modular forest therapy intervention in Mecklenburg-Western Pomerania.

INTRODUCTION: Nature-based interventions aimed at promoting health, enhancing well-being and supporting medical treatment have long been a focus of public health research. In particular, forest therapy and forest bathing are well established in Asia as evidence-informed approaches to stress reduction. In Europe, research on forest therapy is expanding although the field remains comparatively young. Existing studies have mainly focused on the short-term effects of single forest visits while evidence on multiweek interventions and potential medium-term to long-term effects remains limited. The project Forest|Health (Wald|Gesund), embedded within the research consortium T!Raum-Initiative One-Health-Region Pomerania located in northern Germany, aims to address this gap by developing a structured forest therapy intervention tailored to three different target groups.

METHODS AND ANALYSIS: The study protocol describes a pilot study to evaluate a modular forest therapy intervention with regard to feasibility indicators as well as stress-related and symptom-related exploratory outcomes. A total of 120 participants will be recruited across three target groups: community-dwelling adults aged 65 years and older, adults with arterial hypertension and adults with depressive symptoms recruited from treatment waiting lists. Using a multimethod approach, two preliminary studies were conducted: a survey of community-dwelling individuals in the region and focus groups with regional stakeholders. Additionally, a 2-week pilot study of the intervention was conducted. Based on these findings, a 4-week modular forest therapy intervention will be implemented. Participants will be assigned to intervention modules with distinct content using a quasi-randomised procedure. The intervention will follow a pre-post design with follow-up assessments. Feasibility indicators will be assessed as key process outcomes. The primary exploratory outcome will be stress while secondary exploratory outcomes will include psychological and physiological health-related measures.

ETHICS AND DISSEMINATION: The study was approved by the Ethics Committee of the University Medicine Greifswald. Participants will provide informed consent, receive information about potential risks and support options. The results will be disseminated through scientific publications, conferences and public outreach.

TRIAL REGISTRATION: This study protocol is preregistered on the Open Science Framework (OSF; Registration DOI: 10.17605/OSF.IO/C2D5P; last update 16 December 2025).