Trees have inhabited the earth since prehistoric times, and have adapted to survive in some of the harshest of conditions. Throughout their existence, trees have been the subject of damage brought on by inclement weather as well as birds and other animals. In modern times, trees are faced with an increased threat of damage as a result of human activities. Unlike animals, trees do not have a process of healing damaged tissue, or in other words, trees cannot replace damaged tissue with healthy tissue. Instead they have developed a way to seal off a damaged area to protect against further damage through a process called compartmentalization.

If a tree is on the receiving end of a vehicle accident, for instance, its bark will likely incur some damage from the impact. With the protective boundary of bark compromised, the wood comprising the interior of the tree becomes vulnerable to harmful insects and fungi. Without the ability to create a protective barrier around the damaged area, the tree would be faced with death and decay. Instead, a damaged tree will begin to seal off the wound area in order to protect the rest of the tree. New bark forming around the wound is referred to as callous tissue, and this new protective tissue serves to protect the rest of the tree from damage as well as prevent it from drying out. If you have ever seen a tree with what appears to be an abnormal growth protruding from its trunk, you have probably seen firsthand the result of this natural defense. Being struck by a vehicle is an extreme incident through which a tree can incur damage, though other forces such as birds, squirrels, storms and pruning are more common culprits for tree damage.

Although trees are equipped with an ability to seal off wounded areas, all trees do not survive after damage leaves them susceptible to infestation and decay. It can take a tree several years to fully seal off a wounded area, and further damage may occur before the area is fully covered by the new layer of protective tissue. Many factors contribute to a tree’s ability to successfully repair a wound, such as the tree’s age, species, extent of damage, and weather conditions. If the wound is compartmentalized successfully without further damage or decay, the tree is likely to survive.

If a tree on your property has incurred damage, it is advised to hire a tree service professional to assess the extent of damage. While trees with minimal damage may repair themselves naturally without intervention, excessively damaged trees may need to be removed so that they do not become a hazard.