General:
* Ecology: The study of how organisms interact with each other and their environment.
* Environment: The surroundings or conditions in which a person, animal, or plant lives or operates.
* Ecosystem: A biological community of interacting organisms and their physical environment.
* Earth: Our planet, home to all of nature.
Specific aspects:
* Evergreen: A type of tree that keeps its leaves year-round.
* Ephemeral: Lasting for a very short time, often used to describe fleeting aspects of nature like blooming flowers.
Figurative:
* Eternal: Something that lasts forever, often used to describe the enduring beauty and power of nature.
The best "e" word for you will depend on the context of your writing or conversation.