All living things have a sentience. Some organisms are harder to understand than others, but as far as I can tell, life is life. Karma is simply action and it's subsequent consequences. Cause and effect. There is no "good" or "bad" Karma per se. I sometimes get into this a bit aggressively when Vegans try to get high and mighty with me.
You can't avoid Karma, except by not doing anything. If you don't breathe, I am pretty sure you will die, and there are microbes floating in the air that will die inside of you after you inhale them, so there's that. I think that the Karmic elements are fairly clear, and I respect the notion of never killing a tree.
My Karma is such that I still enact other people's desires to have a tree removed. I feel like that's more on them than me, but we all play our part.
You feelin' bad about cutting down that tree last week?
my bad. What I meant to ask more accurately is do we accrue some type of ill will through harming or killing trees? In the way that certain cultures believe that spirits like Dryads will seek vengeance!
