An ANP-BOCR model for the evaluation of urban forestation projects in the Bonagia district of Palermo (Italy)

Thousands of trees will be planted in Italian towns over the coming years as part of the Urban Forestation Plan launched by the Italian Ministry of Environment in 2021. This initiative aims to mitigate global warming, improve urban health, satisfy the increasing desire for nature, and build fairer cities. Traditionally, urban public spaces were found in historic squares, but they are now also emerging in open, originally agricultural, areas and near natural geographical features. This evolving trend inspired “The Right Tree in the Right Town. Urban Forestry for People in Naples and Palermo” research, financed by MUR PRIN PNRR - funds in 2022. The research focuses on architectural projects that generate ecological infrastructures and enhance the spatial quality of new trees, examining the northern slope of Monte Grifone in the city of Palermo (Italy). Based on the exploration of relationships between the mountain and the Oreto Valley, a project proposes a complex of public areas and buildings in the Bonagia district aiming to reestablish an ancient connection between residual rural areas and envision a new urban forestry. This paper presents the development of an Analytic Network Process - Benefits Opportunities Costs Risks (ANP-BOCR) model for the evaluation of urban forestry alternatives in terms of certain and immediate, potential and deferred effects at both the district and urban scales from the perspective of environmental, economic and social sustainability. This model can support public decision-making, even when representatives of local communities, who have their own system of values, are involved in the decision. The diversity of the results obtained from its application demonstrates the need for greater direct involvement of residents in the development of urban forestry projects, as well as dissemination of environmental culture on which to base social cohesion and new identity values.