A single tree on your property can increase the value of your home and help keep it cool. A neighborhood filled with hundreds of trees is a more desirable place to live, and a tree-lined shopping district feels more pleasant and earns higher profits than a barren strip mall.

Plant a thousand trees and you begin to see benefits on a broader scale. Trees improve air quality across large areas by filtering out pollutants and slowing the formation of ground-level ozone. They reduce flooding by absorbing water and improving the quality of storm runoff entering rivers and streams.

– from "Tending the Urban Forest," Pennsylvania Horticultural Society