Justifying investment in urban greening requires a balance of evidence about the supply of services that healthy, well structured urban forests provide and community demand for those services.
There is no doubt that research (and software tools) that began in 1990s and continues today on linking urban forest structure to function and value in ecosystem services has been a “game changer” in improving our capacity to quantify and value the supply of a broad range of urban forest services/disservices, outcomes and benefits. However, without demonstrating demand for those services or some other community attachment to those services, then the case for urban greening may not be appealing enough to decision makers and investors
Decision-making processes in urban forest management are “drenched in human values” (Ives and Kendal 2014). Drawing out evidence about the preferences and values of communities – the DEMAND for (or against) trees, is essential to make a locally relevant case. Revealed preference techniques, such as hedonic price models, provide powerful context-specific evidence. My Brisbane studies provided both an economic valuation of existing tree cover (to compare to costs), AND a policy evaluation of footpath tree shade targets. Proof of community preference/DEMAND for leafier streets and thresholds of tolerance for species diversity (separately published) offered an important alternative source of evidence for shaping the way urban greening and urban forest resilience is justified in Brisbane.