Originally posted by Pabllo:

I mined a copper node and ended up with a deep crater, it helps if its at the bottom of a slope, cut down trees to roll into it and you'll have masses of wood, you just run through and collect it all. You can then plant tress all along the ridge of the crater and voila!, endless wood

I did this exact same thing, only I took it one step farther. I ended up terraforming the crater into a large rectangular pit, planted trees along its edge (and the bottom of the pit), and chopped the trees so they'd fall in.

Also, I'm not sure if this still works, but...whenever I'd plant trees too close together, and left the "chunk" for a few days, I would come back to all of the trees fully grown, even the ones that shouldn't have been.