Temporal and spatial variation in garden and street trees in six eastern Australian cities

Trees are an economically, socially and culturally important component of cities, yet, in single city studies, appear to be less dense in areas of low income and educational status than in areas of high income and education status. We found that this pattern occurred in six Australian cities over the period 1961–2006, with conditions in 1961 predicting those in 2006. Tree presence in gardens conformed similarly to predictors between cities, but the presence of street trees and the type of both street or garden trees did not. Our data suggest that it would be possible to plan to double the number of street trees in Australian cities in present circumstances, but that significant increases in garden tree numbers would depend on increasing the income and higher education attainment of lower socioeconomic groups.