Some humans are not part of the apex species
Plants can't make CO2, and they enjoy the nourishment from animal excrement, so it seems to be a pretty good deal for both.
It's non-sequitur to imply that morality isn't rooted in truth, but instead a fiction contrived by humans, and then to moralize about the rights of trees. This is at the very heart of the problem exposed by Nietzsche. We're all yelling into the abyss pointlessly if morality is defined at the individual level and has no connection with truth. Why struggle then if it's pointless, rather than sit back and enjoy the ride?