Combustion is a chemical change, so the burning of a tree will be a chemical change.

The burning bush is in Horeb.

if your tree smells like that, it's burning. Throw it out immediately. Fibre optics are a type of wire. . . If it smells like burning wire, then your fibre optics on the tree have caught fire!

burning tree

Rubber tree wood is not safe for burning in a fireplace indoors. Rubber tree would can be burned in an outside fire pit. Sometimes the fumes from rubber tree wood can be toxic.