I hate to impose Monkeyfinger. But is there any chance whatsoever that you could upload your CIV4PlotLSystem.xml? Call me lazy, call me ignorant or call me greedy, but I'm really not in the mood to go mucking about .xml's I've got no prior experience in today. Throw it up, and I'll name my children after you. Or at least give one of them a Monkeyfinger nickname. I think the rationale is penned down somewhere as it being attributed to building ON the trees, not beneath or around them. Improvements being 'strung up' in small tree villages. Think Lothlórien. Think Darnassus. Think Ewoks.