I wonder if anyone has figured out away to make trees or any object look burned . maybe some shader setting or something

There are default materials that look like black wood, there is a glowing cigar tip and a set of other glowing materials (Vue 5 or 6 Infinite). With some playing around, you should be able to get some good modified materials together in the Material Editor. Knowing how to use the Function Editor helps a lot, if you have it in your version of Vue.

Monsoon over at 3D Commune (Vue mod) has done some great work with crossed alphamaps/billboards for fire, smoke and rocket exhausts.  I think he has free tutorials and maybe materials.

Pick one of the dead trees in Plants, or use the trunk of a plant species and make the leaves transparent with no color and then;

Change the material Burnt Rock and Lava, make a few modifications to the color, for a burned effect, and add some lines to suggest charring like chipped line. 

I am sure you can get more creative than that.