Environmental Protection Agency Region 6 - Trees, Plants & the Environment

Green Is the Color of Pollution Prevention

If your city hasn't already passed a "green" ordinance or a tree or landscape code, it probably will do so very soon.

According to the National Arbor Day Foundation, cities like Rogers, Arkansas; Midwest City, Oklahoma; Roswell, New Mexico; New Orleans and Fort Worth have been "Tree Cities" for 20 years, and now many other cities are waking up to the greatness of green.

Little Rock now has a land alteration code that requires post construction landscaping and has set standards for site grading, tree preservation and landscape plan preparation. Baton Rouge has a staff landscape architect, an arborist, and a Tree and Landscape Commission. The city has set standards for open spaces, street yards and buffers. Austin has a variety of green laws that cover everything from tree protection and post construction landscaping to erosion control. Louisiana State University's study on green laws lists local tree and plant ordinances at hundreds of other cities.

So what's happening? For years almost every city in the nation recorded a decline in the number of trees along its streets due to development, pollution, disease and neglect. Why suddenly has everyone decided trees are cool?

Glad You Asked

Because trees are cool C cool to look at and cool to sit under. Especially in the summer. Trees, shrubs and other plants shade buildings, intercept the sun's radiation and cool the air.

A single mature, properly watered tree can evaporate up to 40 gallons of water a day, which is like removing all the heat produced in four hours by a small electric space heater.

Trees, bushes or vines not only shade your home, but also your air conditioner unit, which works more efficiently when kept cool.

Helping Cool the Cities

Planting programs can help reduce temperatures and make cities greener. By the time a tree grows to a useful size, heating and cooling costs can be reduced by an average of 10-20 percent. Over their lifetimes, trees can be much less expensive than air conditioners and the energy needed to run them.

Working for People

Trees are always working to help people. The Louisiana Department of Environmental Quality points out the following:

Trees improve air quality by trapping and holding dust particles that can damage human lungs. Tree leaves absorb carbon dioxide and other poisonous gases and, in turn, replenish the atmosphere with oxygen for us to breathe.

Trees attract and keep businesses in a community. Studies show people linger and shop longer along tree-lined streets. Apartments and offices in wooded areas rent faster and tenants stay longer.

Trees create feelings of relaxation and well-being. Some medical studies indicate patients assigned to rooms with a natural view of trees and green open spaces have shorter hospital stays after surgery.

Trees and plants improve water quality by reducing the impact of billions of raindrops, resulting in less runoff and erosion. Also, wooded areas help prevent runoff from washing sediment and chemicals into streams.

Trees and other plants provide food and protection for animals and birds.

Trees reduce noise pollution by absorbing unpleasant sounds.

And if all that's not enough, trees are pretty.

And cool.