Books where characters are one with nature

[Stéphanie]

Hi.
I'm trying to find fantastic/paranormal books where some characters depend on nature to survive. So they live in forest/lake/river..., they don't pollute and they do everything so their environment thrive.
Some examples are the elves in the Eragon series by Christopher Paolini and Wings series by Aprilynne Pike, where they live in the trees/forest, are vegetarian and do everything to protect nature. Other examples are books that have nymphs, dryads, pixies, nature spirits, elementals,...
Books where the main characters or important secondary characters would be my favorites.
Thanks for helping me :)

[Danielle Book Boss]

Series by Dianne Duvall starts with - all the heroes are vegan/environmentally aware/etc. They are immortal guardians so they aren't vampires but they have vampire tendencies.