Glassblowing was another big one. Plus framing for stone construction.

Colonialism seems to born out of the need for more wood since it underpinned all energy, trade, and construction. We can see now how fossil fuels are working out for us instead.

There are some good examples of bay side cities being abandoned due to siltation of their bays, some kilometres worth of silt. Massive centres of trade and then nothing due to erosion because of a lack of trees.

If John/Primitive Tech can focus on efficient energy usage then all the better.