Clear cut the jungle?
Unless you prevent tree regrowth, it's going to grow back several times as thick :v
I imagine elves once cutting trees and harvesting the forest, and then being bitch-slapped by the deity (like this, from another player: "cutting the tree down killed everybody" - imagine if this is your forest retreat and you are the solitary elf left on the ground holding the axe and seeing everyone you've ever known dead and destroyed).
Thereafter they avoid it completely. But dwarves don't believe in that god, so to save dwarves from their own doom they demand they don't bunker buster their own fortress.
Id be satisfied if every tree wasnt like 5 z levels tall, I assume younger trees start shorter, makes building anything take forever, need to designate like 40 trees because they will prevent me placing walls above the first level, if not and trees just sprout fully grown like minecraft or something, thats it for that plan. Maybe just build in firebreaks, pave chunks to stop the fire, or dig moats, ive got a bunch of murky pools and it rains year round, which far as I can tell means infinite water, so long as I dont breach my fortress, I can build areas that fires cant cross.
I just wish there were an easy way to fix the stupid surface holes collapsing trees leave at ground level, even if they don't manage to collapse anything else on the way down. I've been fiddling with DFHack a bit to try and set up a script to automate mass repairs to the surface, but I'm having a lot of trouble figuring out how the tiletype structure is arranged. Ideally, the script would check all tiles starting from the Z-level of the lowest tile that's Outside-Light-Aboveground, and for each tile it finds that's a Soil Wall or a Root Wall with entirely empty space above it (rather than a floor, ramp or something else), and plant a soil floor on top.
The trees leaving holes thing bugs me as well, and yeah tiletypes is a bitch, ive yet to figure it out, I did have to use it to dig a hole once, a miner got about halfway through done with a job digging a channel down to my butcher shop as a vent, then fell asleep, woke up, and rather than finish, climbed out of the hole and wandered off, 3 years passed and no one completed the damn hole, so i tiletyped it, and now its finished but doesnt work, that final tile is marked as underground still, and stops it from ever reaching the shop. If I ever find a thread actually explaining how tiletypes works, i may fix that, it bugs me a lot having that be useless, I could have used that space for something else instead if that was going to happen.