Another g2k1 idea from me...

[Mman]

This one's sort of an add-on to my first one, the mining one.
Here goes:
After a tree dies, you cut it down and take the wood.
Some people may buy the wood, or you can use it to craft stuff.
a good way to also implement my axe repair idea, you keep the axe head, get some wood, and craft the 2 into a new axe.