What is known about what works in community-involved decision-making relating to urban green and blue spaces? A realist review protocol

BACKGROUND: There is now a relatively well-established evidence base suggesting that greener living environments and time spent in urban green and blue spaces (UGBS) can be beneficial for human health and wellbeing. However, benefits are not universal and there remain widespread social inequalities in access to such resources and experiences, particularly along axes of class, race, ethnicity, age and disability, and in relation to efforts to increase the availability and accessibility of such spaces. These injustices often relate to distributive, procedural and recognition-based processes. There is growing interest in how to ensure that efforts to increase access to or use of UGBS (whether through infrastructural or social programmes) result in equitable outcomes whilst minimising potential for exacerbating existing inequalities and injustices. Community engagement is considered an important step towards more inclusive UGBS decision-making, from planning and design to management and maintenance processes. It is thought to contribute to better and more widely trusted decisions, enhanced democracy, community satisfaction, civic interest and feelings of green space ownership, and greater longevity of UGBS projects. However, uneven representation and barriers to participation can create imbalances and undermine these benefits. METHODS: An iterative, multi-stage realist-inspired review will be conducted to ask what works, in what context and in what ways relating to the meaningful involvement of communities in UGBS decision-making, focusing on the skills, capacities and capabilities of different stakeholders and the role of contexts and processes. 'Effectiveness' (or what works) will be understood as a multifaceted outcome, encompassing both the processes and results of community engagement efforts. Following a scoping stage to identify initial programme theory, inclusion/exclusion criteria and derive search terms, relevant databases and grey literature will be searched to identify interdisciplinary literature in two phases. The first phase will be used to further develop programme theories, which will be articulated as 'if then' statements. The second phase searches will be used to identify sources to further explore and evidence the programme and formal theory. We will assess all includable evidence for conceptual richness, prioritising more conceptually rich sources if needed. DISCUSSION: The realist synthesis will explore the key context, mechanism and outcome configurations that appear to explain if and how different approaches to community-involved UGBS decision-making are or are not effective. We will consider factors such as different conceptualisations of community, and if and how they have been involved in UGBS decision-making; the types of tools and approaches used; and the socio-cultural and political or governance structures within which decision-making takes place.