A Tree for Every Space

The social and ecosystem benefits provided by urban trees more than justify the little effort needed to use more places for trees. 

When Dr. Gregory McPherson of the U.S. Forest Service and his colleagues studied the inventory data gathered from cities in California, they found that nearly 64% of the city streets had vacant planting sites. This amounts to some 16 million places where trees could be planted. The researchers also pointed out that the annual air-cleansing service alone of existing trees was equivalent to taking 120,000 cars off the road! When all ecosystem services are considered, California’s street trees contribute $110.63 each — every year. Imagine how these numbers would change if trees were added to the 16 million empty spaces. 

The above example reflects the situation in many U.S. cities, but opportunities for planting go far beyond our streetscapes. While streets offer excellent opportunities for municipal officials to increase the urban tree canopy, adding more trees is something every resident and many business owners can do on their own property. Included in this issue are examples of how even small spaces can be used to provide more trees and more benefits.