So, I got my first elven "ambush" today. They sent 10 elf recruits on foot. Four of my patrolling squad met them in the forest around my fort. Nine elvish corpses were collected & subsequently atom smashed. I purposely allowed one elf to escape, badly wounded, to tell the tale. My four dwarves, clad in leather (no metal in this embark, bummer), suffered three bruises in the fray.
Anyway, I was surprised that the elves attacked me. I have been very conservative with my wood usage, even to the point of getting bituminous coal from traders for my forges (I have discovered magma in the lower caverns, but I am loathe to send my dwarves into danger, with two FB's wandering about). The elves had warned me about respecting the trees, but had not yet set a limit; I have probably cut down only twenty trees since the warning two years ago.
Now, to the point of this post: What if I only pollarded the trees, cutting only the upper branches (a z-level above ground) while leaving the trunks at ground level? Would such pollarding anger the elves, that is, would they count that tree as cut down? On a different tangent, would the trunk grow new branches in the future, more quickly than a new sapling? Is pollarding to conserve wood resources a "thing" in DF? If so, then I continue to be amazed at Toady's omniscience.