The new map that contains the light wood, (New Spires), is live now. It will be on the server for about a week or more.
If you go, be cautious. There are flying Dingo Dongos, Pissed off Crabs, yes, that is plural. Who know what else is there, so watch your wings and backs.

Oh yeah, to get light wood, you need to have advanced hatchets or axes. The trees are at the base area of the large spires. It's a tree with white bark, spirals, and has yellowish/green leaves. You can't miss them.