A Multi-criteria Framework for Climate Change Resilient Street Trees

Urban greenery can mitigate the urban heat island (UHI) effect by 2-4 degrees C. The right trees for urban streets are influenced by several factors including climate, water, soil, surrounding surfaces and plants' specifications. Currently, a variety of databases are used by governments and practitioners to select street trees. Current practices tend to overlook the impact of climate and spatial change in cities on health, performance and longevity of street trees. This study evaluates relevant criteria for street trees and develops a framework for selecting street trees for climate resilient urban spaces. The proposed framework divides into three selection categories: climate change impacted, biological related and built environment related criteria and include 15 sub-criteria: heat resilience, tolerance to drought, salinity, storm and frost, weed potential, allergenicity, climate zones, pests, soil type, watering and pruning needs, longevity in urban areas, cleaning needs, and nearby infrastructure and development, followed by descriptive information includes trees' physical characteristics of size, canopy shape, flowering and etc. The framework is accompanied by a sample database of 125 trees and tool for greater Adelaide metropolitan area. The provided framework and database assists decision-makers, planners and designers to select appropriate trees for urban development and infill projects to achieve more climate resilient urban streets.