With houses being built closer and closer together, people are more concerned about noise pollution than ever before. There is much talk about planting trees and shrubs between the homes to reduce noise levels, both people noise and traffic noise. How effective are trees in reducing noise?
Trees will reduce noise pollution levels, but only if planted correctly.
Noise is the vibration of air molecules, a kind of wave effect in the air. You would think that as this wave of noise reaches a tree that is in full leaf, the wave would stop, and the noise would not go past the tree. After all you can’t see any light through the tree. Unfortunately, that is not what happens. Waves can actually travel around objects. As the noise wave hits a leaf, it goes around the leaf and continues on.
I know this is a bit scientific, but the net effect is that a single tree or bush has very little effect on noise levels. If you need to reduce noise from a neighbor and your homes are close together, the only thing that really works is something solid, like a fence. Even fences with a lot of holes or spaces in them have limited effect on noise pollution.
Are Trees Effective?
In some situations trees will reduce noise levels up to 50% but to be effective you need a tree barrier that is at least 50 feet deep. It also needs to be longer than you might expect, and it needs to consist of both trees and shrubs that start at ground level.
Trees can be used as a noise barrier, but not for the typical home owner. Plant trees to enjoy them, and learn to live with the noise from neighbors – or move!
1) Trees and Shrubs can Curve Noise Pollution: http://www.healthguidance.org/entry/8525/1/Trees-And-Shrubs-Can-Curb-Noise.html – link no longer working.
2) Photo Source: Mrs. Gregerson’s Biology Class Blog