May 1999 - Vol.
Many benefits are quantifiable.
Evergreen trees block winter winds and can save 20 percent on a home's winter heating needs. One acre of trees can remove 40 tons of carbon dioxide, a gas that contributes to global warming, a year. One acre of trees annually produces enough oxygen to sustain more than 1,000 people. Trees reduce stormwater flow by intercepting rainwater on leaves, branches and trunks. Some of the intercepted water evaporates back into the atmosphere, and some soaks into the ground, thereby reducing the total amount of runoff that must be managed in an urban area.