Did James Cameron read this novel from Ursula Le Guin? Because this short 1972 award-winning novel seems to be the Avatar of science fiction books. I consider myself a fan of the author, but all her books are mixed bags (social justice, tendency towards preservation of nature, vilifying humans, very interesting civilizations created by their different evolutionary paths) and this one is no different. You should pick it up if you are in the mood for a quick SF read.
The story is part of a larger universe, in which humans did not start their existance on Earth, but where, for whatever reason, Terra became just one of the planets where humans, in various forms, lived. One of these worlds is Athshe, where tribal, peaceful green humanoids are being enslaved by terrans to cut all their forests and ship them to a deserted Earth. Why would a galactic civilization, capable of light travel and instantaneous communication, need lumber so much is never answered. But hey, it is not like unobtanium was a brilliant choice either. Anything is good as long as we can paint the story of humans being murderous slave loving monsters. I will not spoil the story, but you can probably guess it in a few minutes.
There is however something that I found quite interesting. Our small green friends had a very interesting characteristic, which consisted of having blurred lines between dreams and the real-world. This allowed them to have a deep connection to their subconsciousness, separating their actions from the narrative illusion we are trapped in by our feelings. This Buddhist like super-power brought in some interesting plot twists. Is this where the author is at her best and this book does not dissapoint.
Le Guin was the best anthropology focused fiction writer and even when she wrote mediocre books like this one, she can have an impact.