Environment Planet Earth 3 Types of Wounds That Trees Suffer Tree wounds are the first stage in causing mature tree death By Steve Nix Writer University of Georgia Steve Nix is a member of the Society of American Foresters and a former forest resources analyst for the state of Alabama. our editorial process Steve Nix Updated January 27, 2019 Amaia Arozena & Gotzon Iraola/Getty Images Share Twitter Pinterest Email Planet Earth Outdoors Weather Conservation A good tree-care program includes searching for hints of trouble by inspecting a tree for wounds and other injuries. While a great many injuries to a tree will heal on their own, any break in the tree's surface can be a place where decay can start or where bacteria, viruses, or insects can gain entry to damage the tree further or even kill it. A tree is considered to be wounded when its inner bark is broken or scarred, when its sapwood is exposed to the air, or when the roots are damaged. All trees get bark nicks and most wounds will heal perfectly over time. Tree wounds are caused by many agents but all tree wounds can be classified into three types, depending on their locations: branch wounds, trunk wounds, and root damage. There are usually clear signs and symptoms that indicate the development of tree decay in any of these parts of the tree, and whenever you find them, the wounds should be watched and treated if it's practical. Symptoms that go unrecognized will continue to a point where a tree's health is compromised. Early recognition of these signs and symptoms, followed by proper treatment, can minimize the damage caused by decay. 1 of 3 Tree Branch Wounds Rudolf Vlcek/Getty Images All trees lose some branches during their lifetime and the wounds from these branch stubs usually heal. But when they heal too slowly or not at all, the tree could be in for serious trouble by developing decay. Poorly healed tree branch stubs are major entry points for microorganisms that can cause decay. The biggest problem with wounded branches is when they are broken in a ragged, torn fashion. The prescription for minimizing potentially serious problems is to remove any torn branches with a clean pruning cut, with the cut preferably angled downward to minimize moisture that can seep into the tree. Although at one time, it was believed that painting the sawn stump of a branch with tar or some other kind of sealer was a good idea, this is no longer the case. Tree care experts now recommend that a broken branch be sawn off cleanly, then allowed to heal on its own. 2 of 3 Tree Trunk Wounds Sigrid Intraligi/EyeEm/Getty Images There are many types of wounds on trunks and most will heal on their own. The good news is, a tree has the amazing ability to seal off or compartmentalize most wounds. Still, when a tree trunk receives a wound, the injury becomes a pathway for disease, insects, and decay. This situation might be repeated many times during the life of an individual tree, so a long-term plan for tree care is essential to the continued health of your trees. Tree trunk injury can happen naturally in a forest and the causal factors include storms, icing, fire, insects, and animals. Inappropriate logging and forest management practices cause damage that can eventually affect the entire tree stand. The urban landscape can suffer unintentional trunk injuries from construction equipment, lawn mower dings, and improper limb pruning. A tree can usually recover if no more than 25% of its trunk is damaged around its circumference. Because the underlying cambium tissue is what transport water and nutrients up from the roots to branches and leaves, a more serious trunk injury can kill the tree by effectively starving it. If damage to the trunk occurs, experts recommend cutting away the damaged portion of the bark tissue down to solid wood. Do not use tree paint or any other coating, but watch the wound carefully. Over time, the trunk wound should begin to close itself on its own, provided it has not been damaged too severely. If rot begins to set in, however, the prognosis for recovery is not good, and you may want to consider removal of the tree sooner rather than later. 3 of 3 Tree Root Wounds Shane Hall/EyeEm/Getty Images Surface roots are vital to a tree's health and longevity by absorbing nutrients and moisture necessary for growth. The roots also provide support, and are often damaged during the construction of buildings, roadways, patios, and paving. Care should be taken under a tree canopy to prevent root injury. Homeowners inadvertently kill a tree when removing surface roots in order to make lawn mowing easier, or allowing soil beneath a tree to become compacted by driving on it. Adding extra soil during construction and piling it around the trunk and on top of surface roots is a major cause of tree injury. Injured roots weaken the foundation of the tree, and with time and the advancing decay process, can cause such a tree to eventually blow over in a storm. Prevention is really the best measure when it comes to wounds to a tree's roots because there is little you can do once serious damage has occurred. Should you have a situation in which excavation or construction has exposed torn or broken tree roots, make sure to trim them with clean cuts, backfill the area with good, loose soil, and do whatever you can to avoid further compromise to the root system. If the tree has been seriously damaged, you should know it within a year or so.