Do you love to go hiking? In addition to getting some great exercise, hiking is a WONDERful way to enjoy the great outdoors. If you're paying attention, you can always learn something from Mother Nature.
Many children love to go hiking in local forests. Know what's the best thing about forests? The trees! They provide oxygen to breathe, shade to hike under, and homes for all sorts of beautiful birds and other animals.
As you hike through the forest, you may notice that certain trees have strange growths on them. These growths can be located near the roots, in the middle of a tree, or even in a ring all the way around the tree. They look like spherical bulges that are covered in bark.
These unusual growths are known as burls. In some areas, they may be called burrs. They develop as irregular, wart-like outgrowths. While burls usually start out small, they can grow to be quite large. Burls on redwood trees, for example, can grow large enough for new trees to sprout from!
Scientists believe burls have probably been around as long as trees themselves. Yet, despite this long history, scientists are still not sure exactly what causes them to form. They do have several theories, though.
Many scientists believe that burls begin to form as a result of some sort of trauma to the tree. For example, some burls may be caused by an insect infestation or an attack by a particular fungus. This theory appears to be supported by the fact that burls can often be seen in groups of trees that may have been subject to similar insect or fungal infestations.
Other scientists believe that certain trees may have a genetic predisposition to forming burls as a result of certain environmental factors, such as pollution or the presence of certain minerals in the soil. This particular theory interacts with the previous theory, in that scientists believe that an environmental trauma may trigger the genetic predisposition to form a burl.
Despite these theories, no real consensus has ever been reached by the scientific community. Further complicating things is the fact that scientists have been largely unsuccessful in trying to cause burls to form experimentally.
Why would scientists want to cause burls to form? Although these strange outgrowths may look unhealthy, they generally do not affect the overall health of the tree. Moreover, burls happen to be quite valuable.
In a normal tree, wood grain runs in one direction. The wood inside a burl, however, grows in chaotic patterns. When a burl is harvested from a dead tree and cut open, it often reveals a beautiful, unique wood grain full of colors, swirls, and interesting patterns.
Artisans love burl wood. They use it to make a wide variety of products, including furniture, clocks, bowls, and even interior trim for automobiles. Burls from certain trees, such as cherry, ash, redwood, walnut, and maple, can bring big prices. Some species of trees, such as oak, aren't as highly valued, since their burls often contain holes or rot.
Unfortunately, burl is so highly valued and demanded that poachers illegally strip burls from living trees and sell the wood to unsuspecting customers.