Tree spirits? Far be it for me
to defend Avatar... but, the clear implication of the movie is that Pandora is a biological machine
and a self-aware planet that all the life on is connected to. Its basically one huge Cylon resurrection/Wi-Fi network, powered by the fabulously, generically termed unobtainium.
As has been stated, this story/plot line hasn't ever been particularly "original", at least since the rise of Western Civilization.
And ugg "true scifi"? Do we really need to nitpick that again? (I know the answer, of course we do...) all storytelling is fantasy, no matter the superficial trappings
ascribed to it and everything is a remix