Tension Wood – Definition & Detailed Explanation – Tree Wood and Lumber Glossary

What is tension wood?

Tension wood is a type of abnormal wood formation that occurs in certain tree species in response to mechanical stress. It is characterized by its distinctive properties, including high levels of cellulose and low levels of lignin, which give it unique physical and mechanical characteristics.

How is tension wood formed?

Tension wood is formed in response to mechanical stress, such as wind or gravity, that causes the tree to bend or lean in a particular direction. In order to counteract this stress, the tree produces tension wood on the upper side of the leaning or bending stem. This wood is characterized by its high cellulose content, which causes it to shrink and swell more than normal wood, helping to straighten the stem and restore its vertical orientation.

What are the characteristics of tension wood?

Tension wood is easily distinguishable from normal wood due to its unique characteristics. It is typically lighter in color and weight than normal wood, and has a higher cellulose content and lower lignin content. Tension wood also has a distinctive appearance, with fibers that are more closely spaced and oriented at an angle to the stem axis, giving it a ribbon-like appearance when cut.

How does tension wood affect lumber quality?

Tension wood can have a significant impact on the quality of lumber produced from trees that have developed it. Because of its unique properties, tension wood is more prone to warping, twisting, and splitting than normal wood, making it less desirable for certain woodworking applications. However, tension wood can also be stronger and more flexible than normal wood, making it suitable for specific uses where these properties are advantageous.

How is tension wood used in woodworking?

Despite its potential drawbacks, tension wood can be used in a variety of woodworking applications where its unique properties are beneficial. For example, tension wood is often used in the production of veneer and plywood, where its high cellulose content and flexibility make it ideal for bending and shaping. Tension wood can also be used in the manufacture of musical instruments, furniture, and other specialty products where its strength and flexibility are valued.

What are some examples of trees that commonly develop tension wood?

Several tree species are known to commonly develop tension wood in response to mechanical stress. Some examples include poplar, willow, eucalyptus, and cottonwood. These trees are often found in windy or hilly environments where mechanical stress is more prevalent, leading to the development of tension wood as a natural response. By understanding the characteristics and uses of tension wood, woodworkers can better utilize this unique material in their projects.