I know trees aren't in active development, but there is a subject that has been causing me some anxiety. I don't believe that the multitile trees have roots yet, but there are some common misconceptions about how roots grow that I very much hope don't end up perpetuated by dwarf fortress. Namely, many people mistakenly believe that the average tree's roots are a mirror copy of the above-ground branches in structure - with deep roots and spreading branches, however this is not in general the case.
Most trees have few roots deeper than two feet below the surface (
relevant link). The reason for this is that trees don't have any active circulation, and as such every cell in the tree needs to have reasonably nearby access to air. If artificial means are used to create aerated soil deeper than that (tunnels) then the roots might be able to grow there, but you wouldn't expect to
find many roots when deeper than a few feet. A noteworthy exception is the root system of oak trees, which include a central tap root (
relevant link).
I do realize, on the other hand, that it sounds cool to have to dig around the roots of a forest, so from a gaming (as opposed to simulation) perspective, that might be the choice that gets made.
So here's my question:
How deep do you plan on having tree roots get? Are they planned for this release? If not, do trees (for now) just end at the surface with nothing beneath but soil?
edit: ungreened because answered - thanks!