1.6 The Phosphorus Cycle

Explain the steps and reservoir interactions in the phosphorus cycle.

• The phosphorus cycle is the movement of atoms and molecules containing the element phosphorus between sources and sinks.
• The major reservoirs of phosphorus in the phosphorus cycle are rock and sediments that contain phosphorus-bearing minerals.
• There is no atmospheric component in the phosphorus cycle, and the limitations this imposes on the return of phosphorus from the ocean to land make phosphorus naturally scarce in aquatic and many terrestrial ecosystems. In undisturbed ecosystems, phosphorus is the limiting factor in biological systems.
• Enduring understanding ERT-1: Ecosystems are the result of biotic and abiotic interactions.