1. In a biogeochemical cycle, a chemical element spends time in different places, called: reservoirs
2. As a chemical element moves through a biogeochemical cycle, it moves between "bio" and "geo." the "bio" in biogeochemical refers to biotic reservoirs, or living organisms
3. The "geo" in biogeochemical refers to EARTH specifically, to the abiotic reservoirs where a chemical element can be found.
4. In the terrestrial carbon cycle, the abiotic reservoir from which living organisms directly obtain their carbon is atmosphere