2.3 Biogeochemical Cycles

Biogeochemical cycles

Natural pathways through which essential elements circulate between the biotic and abiotic components of ecosystems.

Decomposition

Carbon in dead organisms is converted by decomposers into CO₂ (returned to atmosphere) or soil organic carbon.

Sedimentation / fossilisation

Carbon stored long-term in rocks (limestone) or fossil fuels.

Flux

The movement of carbon between reservoirs

Carbon cycle

The continuous movement of carbon among the atmosphere, biosphere, hydrosphere, and geosphere.

Combustion

Burning of fossil fuels or biomass releases carbon into the atmosphere

Dissolution

CO₂ dissolves in ocean water and can form carbonic acid, temporarily storing carbon.