Green Spaces over a Roof or on the Ground, Does It Matter? The Perception of Ecosystem Services and Potential Restorative Effects

Cities are becoming more vulnerable to climate change and need appropriate adaptation measures. Previous studies demonstrated that urban green spaces provide multiple ecosystem services, improving the health and well-being of urban residents. Yet different urban green spaces provide different services-provisioning, regulating, cultural, or supporting ones. This work aims first to understand if urban green space users perceive the different supplies of provisioning and regulating services offered by different types of urban green spaces. Second, this work seeks to determine if green roof type conditions, as well as vegetation type and access, affect the users' perceptions of the cultural ecosystem services. This work presents the results of an image-based online survey performed among 376 Portuguese undergraduate students between March and April 2021. The survey is based on nine alternative urban space designs, varying the roof access type and vegetation types. The results show a general preference for urban green spaces with more vegetation, regardless of the type of roof, and a general preference for green spaces with better accessibility. In addition, users' preference for no-roof conditions appears to be linked to the abundance of vegetation and quality of urban design and not to awareness of an existing roof structure and its influence on the natural processes.