Fine wood is easily found in the plains, every wood clump on the map is fine wood, equip shield and axe, hear a buzz, shield up.

Trees do not regrow when you fell them, only grow if you plant new ones.

Use a portal to a forest, strip it clean, then build another portal for next forest. Wood just takes time to gather, does not take that long to fell a forest to be honest. I might just have to see how much can get in an hour.