Long Term Effects of Drought on Trees
The effects of the drought of 2011 in the Houston area will continue to effect and stress trees for many years. The Texas A&M AgriLife Extension Service notes that effect of a severe drought, such as the one in 2011 can last five to seven years. This assumes normal rainfall resumes. The Texas A&M Forest Service estimates over three hundred million rural trees and nearly six million urban trees have died, so far, in Texas as a result of the 2011 drought.
Certain diseases will be on the increase, particularly fungus infections. Additionally, stressed trees are more vulnerable to insects and other pests. The drought depletes the carbohydrate reserves of the trees, curtailing their normal growth and reducing their ability to resists disease and insects.
Visual indications of negative drought effects include:
- Limb dieback.
- Asymmetric, or lopsided, crown.
- Reduced growth.
- Smaller, yellowish foliage.
- Fungus infection.
It can be difficult to tell if a tree is actually dying. The simplest method is the ‘twig’ test. During the winter, select a few twigs. If they have a springiness and return to form, the tree is simply resting; if the twig snaps easily, the limb it came from is likely dead.
If there is a damaged tree which needs to be trimmed, the Forest Service urges that a professional be brought in to deal with the problem. They have the expertise to know what to look for and what to remove to minimize further damage. Additionally, the also have the equipment and experience to properly remove the dead portions as there are always safety concerns.