Sun burned bark on chopped thin bark trees.

[lennard]

The tree in question is a 5 trunk Celtis chopped many years ago. The tree was not given the chance to grow over the wounds so over time the deadwood cracked an left the opportunity for water to drain to the center of the deadwood of the trunk.

When I got the tree I noticed this sunburned area but I thought it was caused by placing a shaded area of the trunk in sunlight to suddenly and that was why it was sunburned.

Here is the first pic June 2009 when I noticed the sunburn area:

wond 2.jpg

I don't move/turn the tree because I don't want to cause further sunburn. The sunburned area enlarged this season:

wond 3.jpg

I can do nothing about the burned area because the bark is dead, but I want to try and prevent this from happening again because I have also noticed this on another thick chopped Celtis.

Could it be a matter of the core of the trunk has rotted deep inside because of all the cracks letting in a lot of water and when it is very warm the water/vapor is forced to a layer just beneath the bark and this makes the bark getting too warm?

I have not noticed this on non chopped Celtis trees.

Would appreciate your thoughts on this.

Lennard