Our urban forest is more than just our ravines and remaining natural areas. It includes the trees and under storey plants growing along streets and even in your backyard. A healthy urban forest is diverse, both in species and age, and supports a wildlife population. Some parts of the urban forest are 'geriatric', with many older trees reaching the end of their life span but few young trees to replace them.
In new developments, there are very few trees at all. In other areas, one tree species may dominate the landscape. In addition to these imbalances, our urban forest faces many stresses imposed by dense human settlement. These include excessive paving, compacted soil, air pollution, salt, above- and below-ground utilities and lack of space.