Have been working on figuring out tree parameters. I haven't gotten as far as I would like, but:
Trunk_period: no idea. Couldn't notice any differences at all from changing this, under various conditions.
branch densities: as you would expect, they create more often branches of that type.
max trunk height: the highest height of
A trunk tile, not necessarily in a straight line.
heavy branch radius: seems to be the radius heavy branches can occur at. Does not depend on the trunk branching amount or where trunks are. You can actually have trunks branch out further than heavy branches do. So if this is = 1, you will have heavy branches in a 3x3 area around the center, period.
branch radius: similar.
trunk branching: Seems to be a combination of how "branchy" the shape is (twisting around, not straight line) PLUS how wide out the reach, in one parameter
^again, all three of these seem almost independent of one another. Branching of trunk can seemingly go out further than other branches do, for instance.
max trunk diameter: seems to only affect the base of the tree, and only go up to a max of 3x3 in size, no matter what you set.
Also, trees appear to be limited to a 7x7 area above their first tile in width, no matter what parameters you set. If you set all the branching radii and everything super high, you just get fully filled 7x7 rectangles going up. As you set them lower, it will take on different more or less filled oval shapes.
Also, biomes or perhaps temperatures or something can affect these variables. I have a world with ONLY one species of tree in existence, and on some embarks, it has 3x3 trunks all over the place and massive 7x7 canopies. And on other embarks, they are exclusively 1x1 initial trunks and tiny canopies
I haven't made any rhyme or reason out of it.