Hadn't really noticed the tiles until it got pointed out. Not too bad, really. Would love to see how Toady handles it.
I'm thinking the trees individualization he hints at will probably have to include determinant size (by mass? Number of branches?) that vary by species, or group. That would lead to interresting variation in forrests.
Related to that, will be things like the tower caps and fungi wood. They may have smaller determinant sizes because of their subterranean environment. Also, the cavern size itself will be an external determining factor of a given tree's growth potential. The solution for cavern tree farms is obvious: multi-z-level channel clearing for tree growth areas.
I'm not sure if "Balancing" is the forefront question for these trees as much as what changes to the harvested product are we going to see. Will we have Fir Branches that are harvested from the extremeties of the specimen that are good for small crafts, arrows, charcoal, etc. and Fir Logs that are for larger furniture, wall building, etc.? That may even be greenable. If this is the case, I could in some ways seeing this as self-balancing, where you'd get just as much of the good stuff as we'd gotten before for the things that need large wood (beds, doors), and a great deal of the smaller stuff, the "Energy Forrest" type of product for smaller craft and energy needs, i.e. charcoal.
Toady, is partial cutting (pollarding) of a tree going to be possible? If tree-topping of this sort is possible, will the tree continue to grow?