This is a game balance issue, not a bug.
Still, I hope the developers take a look at it and address it.
I usually play 3v3 skirmish with hard AI.
Such games can easily last more than an hour.
After one hour there are almost no trees left around the map.
That creates game imbalance where European nations can still produce a great deal of wood via two factories, yet natives and Asian nations have no way to produce wood.
Wood is crucial in order to train cannons, therefore long games give European nations unfair advantage.
My suggestion is to increase the amount of wood for each tree from 300 to 600.
That would solve the problem.