Ulperioleri

Fantasy world revolving around a Uge-big tree. Main branches thick and long enough to house entire nations. Most national capitals/power holds near the tree trunk due to less of a chance of those breaking off.
Conflicts arise when some branch from above breaks off due to over-load, natural withering or over-harvesting, and falls down, crushing against branches below.
Central conflict being all the branch-nations trying to somehow regulate each other not to carve into the central trunk too haphazardly and cause the entire thing to break off. Constant worry of bottom-branch nations worrying about wrecking falling branches, and upper-branch of someone hollowing out the trunk below them and everyone falling off.
How would you write something like this without coming off as a preachy environmentalist though?
https://i.poastcdn.org/a278e0af15bd7510f066dc2289025b82d123050b824514301e97cfe8696f9450.jpeg