Science
Biogeochemical cycles.
Definition
Biogeochemical cycles are the pathways by which essential chemical elements and compounds move through the biotic (living) and abiotic (non-living) components of Earth's systems. The major cycles include the carbon, nitrogen, phosphorus, and water cycles.
Examples
Real-world.
- 1 The carbon cycle moves carbon through the atmosphere (CO₂), organisms (organic molecules), oceans, and rocks (fossil fuels, limestone)
- 2 The nitrogen cycle converts atmospheric N₂ into ammonia through nitrogen-fixing bacteria, making it available to plants
- 3 The phosphorus cycle is unique among major cycles because it has no significant gaseous phase—phosphorus moves mainly through rock, soil, and water