Greenspace and mental health research – the question of scale

Abstract Background Greenspaces have been proven to promote mental health and wellbeing. Research is conducted in diverse fields with various methods. However, studies and theoretical concepts frequently fail to address or define the scale of the environment in question. Furthermore, the different types of greenspace at the same scale are often inconsistently or inaccurately defined. Such limitations may impede the comparability of results and interdisciplinary understanding. The aims were therefore: 1. To provide a quantitative overview of the combinations of greenspace and mental health measures used at the ecological scales; 2. To embed the results in the existing theoretical background. Methods A systematic search and a scoping review were conducted, applying an PEO framework. The data was charted with an extraction table and analysed with regard to the ecological scales which are: landscapes, ecosystems/land-use types, and species/natural elements. Preliminary Results Generally, distinct greenspace measures are used at different scales, while the mental health measures do not show such a clear pattern. The “landscape” scale is most often assessed via GIS approaches. The scales “ecosystems” and “species” are mostly investigated via interventions. Overall, the “ecosystems” scale is the most frequent in both research and theory. Qualitative mental health measures often focus on ecosystems. However, the qualitative theoretical concepts are based on landscapes, e.g. Therapeutic Landscapes. Species and natural elements are rarely directly addressed by both studies and theories. Conclusions We propose increased attention to the types and scales of green and nature at both the theoretical and the practical research level. Established ecological scales can provide a common basis for interdisciplinary research and improve the comparability of studies. This can elucidate the potential differences in the impact of the diverse forms and dimensions of nature on human health. Key messages • The methods employed to assess the relation between greenspace and mental health vary according to the ecological scale. Ecosystems are the main focus in research and theory, species the least. • The type and scale of nature should be considered in environmental health research and theory. Established ecological scales can provide a basis for interdisciplinary comparability and understanding.