AP Environmental Science Flashcards: The Phosphorus Cycle
Written by AP Content Team, Verified for 2026 AP Exams, Last updated: May 2026
Review key ideas with interactive flashcards. This set includes 10 cards to help you master important concepts.
What is the phosphorus cycle?
The phosphorus cycle is the movement of atoms and molecules containing the element phosphorus between sources and sinks.
Card 1 of 10
All Flashcards (10)
What is the phosphorus cycle?
The phosphorus cycle is the movement of atoms and molecules containing the element phosphorus between sources and sinks.
How does the primary reservoir of phosphorus influence its availability to living organisms?
Since phosphorus is primarily stored in rock and sediments, it is released very slowly through weathering, making it scarce and a limiting factor for life.
What key component is absent from the phosphorus cycle that is present in the carbon and nitrogen cycles?
There is no atmospheric component in the phosphorus cycle.
Why is phosphorus often considered a limiting factor in ecosystems?
Because the cycle has no atmospheric component, phosphorus is naturally scarce and therefore limits growth in many aquatic and terrestrial ecosystems.
Based on its major reservoir, is the phosphorus cycle primarily a fast or slow biogeochemical cycle?
It is a very slow cycle because its major reservoirs are rock and sediments, which release phosphorus through slow geological processes.
What are the two main types of ecosystems where phosphorus availability is often a limiting factor?
Phosphorus is a limiting factor in many aquatic and terrestrial ecosystems.
Where is the vast majority of Earth's phosphorus stored?
The vast majority of Earth's phosphorus is stored in rock and sediments.
What are the major reservoirs of phosphorus?
The major reservoirs of phosphorus are rock and sediments that contain phosphorus-bearing minerals.
Define 'source' and 'sink' in the context of the phosphorus cycle.
Sources are where phosphorus originates (like rock), and sinks are where it is stored (like sediments).
What are 'reservoir interactions' in the phosphorus cycle?
Reservoir interactions describe the movement of phosphorus between its sources (like rock) and sinks (like sediments and living organisms).