Trees Aren't Just Good-Looking

Trees do more than add beauty to a landscape; they reduce pollution and conserve energy, as well as enhance the environment in a number of other ways.

Urban areas, in particular, can benefit from trees, according to the U.S. Forest Service. Besides providing attractive color, form, shapes and texture, trees screen harsh scenery and provide privacy. They muffle noise, trap pollutants such as dust, ash, pollen and smoke, and reduce air pollution by utilizing carbon dioxide and releasing oxygen.

"Trees absorb carbon dioxide for growth and, in so doing, they reduce the amount in the atmosphere and release oxygen," said Andrew Gillespie, assistant professor of silviculture in the Purdue University department of forestry and natural resources.

Gases created by human activities build up in the atmosphere, Gillespie explained. Then, when sunlight enters, it is prevented from radiating back into space by the layer of gases. The resulting heat buildup, referred to as the greenhouse effect, threatens to raise global temperatures to an unprecendented level.

"We can make the problem worse by cutting trees down," Gillespie said, "but to actually improve the problem, we'd have to plant an area the size of Australia."

Harvey Holt, Purdue professor of forestry, said trees are frequently called nature's air conditioners.

When trees shade homes and offices, air conditioning needs are reduced by as much as 30 percent in hot months, according to the U.S. Forest Service brochure, Benefits of Urban Trees. Trees also serve as windbreaks in winter, reducing heating needs by as much as 50 percent, according to the Forest Service. Both shade trees and windbreaks result in a reduction of fossil fuels burned for energy, which is good for the environment and economical for the consumer.

Deciduous trees should be planted for shade so they will block the sun in the summer months, yet drop their leaves in the fall to allow sunlight through in winter months, Holt said. They should be planted on the south and west sides of buildings.

In inner cities where heat is absorbed by concrete, especially beneficial for their cooling effect, Holt said. In addition, they reduce glare on sunny days and reduce wind speed.

Evergreens are the trees of choice for windbreaks because they retain their needles year round. They work best on the north side of a building.

In addition to their environmental and energy saving advantages, trees also increase property values. The Forest Service states that healthy trees can add as much as 15 percent to residential property value. And office space in a wooded area is in more demand, making it more valuable to sell or rent.

This article was featured in The Farmer's Exchange.