I love this question! I've seen the movie Avatar, but I don't know it well enough to refer to specific scenes. Still, I think that I can offer enough of an answer here to get you started.
Here are some fundamental concepts in Transcendentalism that apply directly to the film:
1. Nature is a way for humans to connect with the divine.
2. Individual wisdom and self-betterment may result from direct connection with and reflection on nature.
3. Wisdom may (or should) lead to social action.
Most of the humans in the film Avatar simply see nature as untapped resources. They're happy to take, destroy, and move on to the next planet. The few, more enlightened humans in the movie understand that nature is not only important in and of itself but that it also has some sort of profound connection to what we call the "soul." They gain awareness through their direct experiences with a more pure world (full of more pure creatures), and that awareness drives them to oppose their own people's attempts to exploit yet another planet.