How do they get down? Do they need to?
Gliders? The plants look highly specialized; the original growers might have subsumed hollow tubes into the trunks larger branches. Those would, theoretically at least, admit bi-directional travel, unlike gliders. You would have to get down at some point: the top-soil presented is no where nearly thick enough to support even modest population.
I like the notion of vertical travel being a part of the organic landscape, and the farms, not a metaphor for conservative isolation, but a nostalgic sense of play for, say, Fifth Men in that old Olaf Stapledon novel. Maybe the atmosphere is more dense and the inhabitants travel via hot air balloons, or even better, Air Baleens. The cows, of course, do what cows always do.
