In Ecology:
* Biogeographic realm: This term emphasizes the larger geographic scale and distinct characteristics of a region.
* Biome: This term refers to a large-scale community of plants and animals that share similar adaptations to a particular environment.
* Habitat: This term focuses on the specific environment where organisms live.
* Ecological niche: This term describes the role an organism plays within its ecosystem, including its food sources, habitat, and interactions with other species.
* Ecoregion: A smaller geographic area characterized by distinct ecological features and biodiversity.
In other contexts:
* Biosphere: This term refers to the entirety of all living organisms and their environments on Earth.
* Ecological zone: This is a more general term for a region characterized by similar environmental factors and life forms.
* Zone of life: This term emphasizes the presence and activity of living organisms within a specific area.
The best alternative will depend on the context in which you are using the term "life zone." Consider the specific features you are trying to convey and choose the term that best reflects those features.