[Arid_gardener] Question from Home-Hort WWW page

[TRLank at hotmail.com]

Tim
85044
TRLank at hotmail.com

I have two "scrub" oaks near each other about 10-14 feet tall with 4-5 inch trunks.  Not sure of the actual name, but they're not one of the famous varieties, although I bought them at a nursery about 12 years ago.  One of the oaks has a large area about  2 1/2 ft long and running almost halfway around the trunk where the bark is missing down to the core. The exposed core looks dry and brown.  The tree otherwise looks OK compared to its neighbor, which is fine.

This area is on the SW side of the trunk but don't think it's sunburn. I think there was originally a suppoet pole on this side and it could have rubbed / abraded in this area when young, which would explain the length.  Any other speculation as to the cause??  Is there anything I can do to help the tree cover this up eg whitewash? Or anything I can cover it with that won't hinder the tree from healing itself eg tar?
Worried about bugs & disease.
Thanks.