I am wondering about trees lately (I'm *not* a treehugger though!).

Does someone know whether trees 'spawn' at all or that they will regrow once they are cut down by someone?

And also, is it possible for someone to but down trees on the tribe-lands of others?
Or is that strictly restricted to the owners of those lands?

At this time in the game there are trees a-plenty but I can imagine that a tribe (or even solo players) cut down trees for further processing (buildings, fences, tools etc) and in that process make a barren countryside. So how will trees be replenished?

Thanks.