Avatar was pretty much an unaccredited adaptation of Ursula K. Le Guin’s 1972 novella “The Word for World Is Forest”, which was about a benevolent race of alien beings who happily inhabit dense forests while living in harmony with nature until they are attacked and slaughtered by invading human soldiers.
It also has elements of Poul Anderson’s ‘Call me Joe,’ where a quadriplegic human takes over an alien body in order to explore Jupiter.
FReegards
I’ve read a few of her novels but not that one.
Next time I’m in the used book store I will have to look for it.