Our apple tree has a main branch off of the trunk that has lost a lot of bark, like it has been peeled off (and perhaps over the last few winters the squirrels may have done this).  The branches above this damage are dying, can I save it by wrapping?  Is this damage by sun, animal or disease?  The tree produces great Braeburn-like apples when the stars align here in Colorado to allow the fruit to form. Thanks!