Introduction
The use of trees for windbreaks serves multiple purposes. In our area we are accustomed to seeing these types of establishments. They are considerably helpful if made and used in the right way. I will share a few of their major purposes as well as some important considerations in planting and creating windbreaks or shelterbelts. I will also provide links to finding additional information. |
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Purpose
The general purpose of windbreaks is to simply reduce the wind. Windbreaks alter the course of the wind. They can stop a large percentage of wind and force it over the tree line. It may also go around the ends of the windbreak. Therefore, strategic placement is critical. Shelterbelts are a frequent sight in rural areas. There purpose may be to keep wind away from buildings or homes. Windbreaks for this purpose help in many ways. Not only to the keep the wind out, but they keep energy costs down in the homes they surround. They provide a nice shaded boundary during summer for the residence and keep out cold wind and snow during the winter. However, they can also provide protection for livestock, fruit and vegetable crops as well as field crops. While in areas along roads they can be used to reduce the amount of snow buildup on the roads. This makes winter time less dangerous and creates easier mobility for transportation using the roads. Snow gets caught in the windbreaks instead of collecting on the roadways if they are placed correctly. An additional fun reason for having windbreaks is that they become homes to wildlife. This can add character to the area with additional wildlife animals.
Creating Windbreaks
Establishing windbreaks takes planning to make them beneficial to specific areas. The first thing to consider is the main purpose of the windbreak. Then you can consider some of the major factors there are the spacing from roads or driveways, buildings, utility lines and draining ditches.
Height of trees and Length of the windbreak
After this has been determine consideration needs to be placed on the spacing between the actual rows. Windbreaks should consist of trees that can be easily grown in that area. The height of the windbreak will grow as the trees do and protect a larger area as they grow. The ultimate height should be considered. If immediate results are expected taller or faster growing trees may need to be planted. When determining the length of the rows the height should also be taken into consideration. Considering that the taller the trees and the longer the windbreak the more area they protect. By taking the expected height and multiplying times three you will get the desired minimum length to be effective. This can be altered to meet the needs of the area.
Density and Formation of Windbreaks
Another way to create additional cover from a windbreak is two make two windbreaks at different angles come together. Connecting several one directional, straight windbreaks together at an angle will produce a larger sheltered area. These are called legs of a windbreak. A prevailing wind direction is taken into consideration, especially for any breaks in the tree fence or a one legged windbreak. Any openings in the windbreak should not be straight through with the prevailing wind direction, they should include bends or start at a different angles. The prevailing winder direction should not match any of the openings.
Another crucial factor is the density. Density can improve or hinder the effectiveness of a windbreak. In windbreaks with a very dense population of trees a buildup of air can occur on the windward side. Then on the leeward side an area of low pressure develops. Then the buildup from the windward side pushes the wind over top of the tree line and the leeward side of low pressure pulls the air downward. This in turn reduces protection downwind and also creates turbulence. The spacing of trees can also alter the effectiveness of a shelterbelt. Spacing is a factor between tree rows and between individual trees. However, I did not find a definite answer for correct spacing due to variance in characteristics of landscape, trees, and type of shelterbelt. Smaller trees should be placed closer together as long as there is adequate room still available when they are full grown. The maximum size is what the spacing should be based on. Larger trees are farther apart. This various with the specious used and the landowners intent for the windbreak. According to multiple websites, spacing rows 20ft apart is usually ideal, but can also be altered.
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| Newly planted Windbreak | Unique curved windbreak sytem |