The tough exterior surface of a tree known as the bark protects the tree from being damaged by a number of insects and some environmental factors. Once the bark of the tree is partially or completely removed the tree is more vulnerable to infection and may soon die because of this. Basically the tree will not likely survive once the bark has been compromised significantly. Sometimes people accidentally injure tree bark by doing simple things like utilizing gardening power equipment close to neighbouring trees.
However, if the damage is mended as soon as the incident occurs then your tree will possibly strive without any problems and replenish its bark in under year, so much so, the spot of the initial accident will not be noticeable to any one else. While certain types of damages are repairable, those that occur on older less vibrant trees will not be easily or likely fixed. In addition large areas that go further than the bark to deeper layers of tissue are actually irreparable. Yet there are still a couple things you can do after your tree has been negatively impacted none the less.
Tree Bark Solution (Optional)
Pesticide (that is safe for trees)
How you approach the blighted area will be related to the severity and what is potentially happening to your tree.
If a large chunk has been removed from your bark you will have to find that portion to begin repairs. Retrieve the portion that has come out, cut a bit of duct tape and fix the piece to the tree with the duct tape. Strap your duct tape around the tree with the piece in place to ensure that it will hold. This should stay put during rainy seasons because of the bonding strength of duct tape. However, if it starts falling off merely replace the previous duct tape with a bit of new duct tape. This should be left in place for three months and not much longer as the tape can actually damage the existing tree bark. During this time look in on the tree to ensure that it is healing properly. Basically once the tape is removed the bark should stay on the tree without needing the tape.
If you cannot find the missing bark, or there is none, just a big enough area left without bark coverage you will have to nurture the wound to incite rapid healing. Depending on the damage to the area you will have to refine the bit using a knife or blade. Get rid of any jagged pieces and then construct an eye shape on your damaged area with the tops and bottom being narrow and the middle having more width. The tree will heal rapidly and should not succumb to its injury. During this time insectscan hide in the wound and negatively affect the tree therefore you may wish to spray that section with a bit of pesticide to get rid of any eggs that may hide in this susceptible area. When the tree has restored itself this will not be a big concern.
You may think about utilizing a store bought healing solution. It works by forming a protective layer over the tree after you spray the contents from the can. Essentially it works similarly to a sealant. It is not certain if that this will promote healing and this may actually have the potential to destroy the existing tissue. However, you may try it if the methods here do not prove useful in your situation. The worst thing that may occur is that the tree dies as it intended to anyway.