[Arid_gardener] Question from Home-Hort WWW page

[timbinaz at cox.net]

Tim Boland
85044
timbinaz at cox.net

I have a 14' tall Arizona Ash with a 5" diameter trunk near the ground. The bark on the lower 2' of the trunk became sunburned, dried up, and broke away.  The core wood is now exposed where the bark broke away. The problem seems to be expanding a little.  Is there something I should do to seal the exposed wood core and to prevent the problem from getting worse?  Other than this problem with the bark, the tree appears to be very healthy. 
Thanks for any advice you can offer.