trees grow back in the game. Replanting may increase local abundance, but since the player can only operate 1 fortress in game at anyone time, and since it is restricted to a tiny fraction of the game world, the relative destruction of trees is very minor.
True, but I imagine it's safe to assume that the player's fortress is not the only faction cutting down trees. And, if I remember correctly, the Elven diplomats usually say something along the lines of "these trees are of particular importance to us, but we are willing to part with
n of them." And reading that statement with this particular theory in mind, one could very well infer that the trees you're cutting down
belong to the elves...
Elf 1
: Crap, crap, crap!
Elf 2
:
What? What is it?
Elf 1
: Remember how you said that one day the humans/dwarves/goblins/whothefuckeverelse would use up all their wood and proceed to take ours...?
Elf 2
: Uh,
yeah.
I mean, geeze, it was only
the single most formative event in the history of our civilization.
Elf 1
: I think it's already started.
Elf 2
: ... ... ...
Goddamnit! *Sigh* Get me my !!Mahogany Longsword!!.
Elf 1
: Oh, so we're gonna kill the dwarves?
Elf 2
: What? No! That would be unreasonable. We're going to send a diplomat to insult them and make absurd demands. We don't kill them until
after they kill our diplomats and/or rob our caravans a few times.
Elf 1
: Oh! That's sneaky! ... wait, then why did you want me to get you your sword?
Elf 2
: Because I dislike you, so I am going to kill you, then cook you, then eat you to absorb your essence and thereby become that much stronger.
Elf 1
: ... oh. *Is stabbed with burning sword*