Tree Bark Gnawed by Animal
Our business is located in a suburban industrial park and we have a number of trees that were planted in 1995 and are about 8" in diameter. One of our employees noticed that two of the trees were severely damaged in just the past day or so. I have attached a photo to show the damage. The damage, which appears to be from a gnawing animal, goes completely around one tree and half-way around the other (thus far). The gnawing is about 6 " in height. Do you know what is causing this, and is there anything we can do right now to stop this from happening to all of the remaining trees? I assume that once the tree is completely girded like the first one, that it will soon die. Is there anything we can do for it?
Sorry to hear about the tree damage on your property. Rabbits and voles were feeding on the nutrient rich cambium located just below the bark of your trees and shrubs. This is the area that moves water and nutrients between the roots and leaves. If the critters ate all the way through the cambium and all the way around the tree, you are right, it is dead.
I would wait and see what happens to the trees. I have seen some severely damaged trees survive. Badly damaged trees and shrubs will often start to leaf out in spring using energy reserves in the buds and stems. If the plant is unable to pull up water and nutrients from the roots the partially developed leaves wither and die. Then you know it is time to remove the tree before it becomes a hazard. If the plants continue to grow there is enough living tissue to support the plant. Allow partially damaged trees to recover on their own. We often cause more damage trying to help our trees than any repair work we can do. Pruning paints and tars should NOT be used. These traps disease organisms and slow or even impede the recovery process.
Make sure all plants receive proper care this season. Use organic mulches on the soil (do not pile them around the trunk and stems) surrounding the plants and water thoroughly whenever the top 4 to 6 inches of soil are crumbly and moist. Too much water can be just as detrimental as insufficient moisture.
Protect young trees and shrubs with a 4 feet tall fence of hardware cloth (a fine mesh heavy duty material somewhat like chicken wire) sunk several inches into the ground to prevent vole damage (mouse-like rodent) at ground level and most rabbit damage. Mature trees like the one you showed are usually only bothered during years where the vole and rabbit populations are high – like this past winter.
Repellents may help discourage rabbits if applied before they start feeding and reapplied throughout the winter. I am not aware of any repellents that work on voles and I am not a fan of poisonous baits. I worry about the negative impact on owls, hawks and other predators that eat these rodents and help keep their populations under control for us.
Consider consulting a certified arborist to help you deal with trees that will need to be removed. They have the training and equipment to do the job safely.