I LOVE THEM AND EXPECT SOME TREANTS IN THE MIRACLEVERSE IT'LL MAKE SENSE SOON.
I've heard people claim they're JUST LIKE the Discorded!Mane Six, and while they share the same root idea, opposite Mane Six, their execution is different. For the purposes of this, I'm calling them Tree!Mane Six because they're Treants.
Tree!Applejack is greedy and conniving, actively having a motive to lie, while Discorded!Applejack just... flat out says untrue things; not stories, just obviously the opposite of the truth, like saying "I absolutely refuse" while doing exactly what Twilight asked her to.
Nothing special, just blatant falsehoods. Tree!AJ'd rathe