Core existence

Biosphere, ecological core, ecosystem or umwelt:

core - meaning centrally important to our way of life

existence - meaning material conditions, or the entire behavior of biological and physical materials of all life on earth and objects in the universe.

biotic community - meaning all living things in an area

habitat - meaning a specific area, place, space or location

ecological system - meaning both the habitat and the biotic community acting together as a functional unit, or ecosystem.