Associations Between Urban Green Space Quality and Mental Wellbeing: Systematic Review

With the rapidity of urbanisation, concerns about citizens’ mental wellbeing issues are on the rise, and simultaneously, the issue of land use conflicts is becoming increasingly prominent. As a nature-based solution, the role of urban green space has been continually emphasised in the past decade. In urban areas facing scarce land resources, improving the quality of green spaces appears to be an important approach. This review aimed to systematically elaborate the studies regarding the associations between urban green space (UGS) qualities and mental wellbeing, following the Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Twenty-two articles were included, and most of them had a cross-sectional design. From the analysis of the data, it emerged that the definition of the quality of green space is heterogeneous. Natural elements, particularly vegetation diversity and water features, consistently showed positive associations with mental wellbeing, while the effects of spatial features like accessibility showed mixed results. The impact of facilities and amenities appeared more complex, with their benefits heavily dependent on the design and maintenance. More evidence is needed to determine the mental wellbeing benefits of maintenance and the development of facilities and amenities for UGSs. In addition, the assessment of mental wellbeing relied on various self-reported scales, with different scales targeting different aspects. Instrumental measurements were rarely employed. Future research should employ more rigorous experimental methods and standardised quality assessment tools.