Oaks are a prominent species of tree in Austin, Texas. However, in recent years, a considerable number of oaks in Austin have been destroyed by the disease known as oak wilt. Oak wilt is caused by a fungus which causes the water-conducting vessels of the tree to become clogged. As a result, this prevents all parts of the stem beyond the blockage from receiving much needed water for continued viability. In an attempt to bring these devastating effects under control, the city of Austin has adopted an official policy regarding the appropriate disposal of wood affected by oak wilt.
Chipping or shredding the wood from trees affected by oak wilt is an acceptable means of disposal. This is permissible because the wood dries when chipped or shredded. The fungus responsible for causing oak wilt, also known as Ceratocystis fagacearum, cannot thrive once the drying process begins. Much like other types of fungi, which require moisture to thrive, once the source of the moisture is depleted, the fungi is destroyed. In spite of the demise of the tree, this is an environmentally friendly means of disposal, as the chipped or shredded wood can serve another purpose through use as mulch.
Another acceptable means of disposal of wood affected by oak wilt, although perhaps a little less environmentally friendly, is burning. Burning affected wood will kill the Ceratocystis fagacearum. Again, the heat from the fire supplies a means of drying, depriving the fungus of the moisture it requires for survival. And since the fungus is not spread through the smoke, there is no cause for concern that this manner of disposal might potentially affect healthy oaks.
As per the city’s policy, any affected wood that is not chipped, shredded or burned shall be disposed of at a landfill. An Austin tree trimming specialist who is familiar with Austin oak wilt and the various appropriate means of disposal of affected wood can likely direct you to the landfills in your area that are prepared to receive diseased oaks for disposal.
In instances where diseased oaks are identified, but are not accessible for chipping, shredding, or burning, the policy indicates that the tree shall be girdled. Girdling occurs when a ring of bark and underlying tissue are removed from around the tree, generally for purposes of destroying it. Once the diseased tree is girdled, it is then treated with an herbicide for desiccation (or drying). Desiccation, of course, facilitates the destruction of the fungus by depriving it of its life-sustaining moisture. This is an especially important procedure if the diseased tree is inaccessible, but happens to be within the vicinity of healthy trees, which could be negatively impacted if the diseased tree remains untreated. Contact an Austin tree care professional to assist you with such a procedure for affected oaks on your private property.
As per the city’s policy, one final, acceptable means of disposal of affected wood is through the use of firewood. This is yet another environmentally friendly means of recycling the wood. However, city policy indicates that the firewood shall not be stored near healthy, unaffected trees and shall be stored under a clear plastic covering with the edges tightly secured, perhaps dug into the ground, so as to prevent any spore-carrying insects from spreading the disease to surrounding healthy trees. The plastic covering also provides a solarizing effect, which speeds the drying of the wood should any moisture remain. The policy recommends the use of clear plastic so that escape holes are not easily recognized by the disease-spreading insects.
About the Author: Andrew Johnson is the owner of Central Texas Tree Care, a leading provider of Austin tree service in Central Texas. Certified ISA Austin arborist services including: tree trimming, tree removal, tree care and oak wilt treatment. For more information on Austin tree service, please visit http://www.centraltexastreecare.com.