Phosphorus Cycle
• BR: How do humans use Phosphorus?
• SWBAT: -Recognize the steps of the Phosporus
• SWBAT: -Understand the affects that the
phosphorus cycle has an a system.
• Organisms need phosphorus for biological processes. It is a
major component of DNA/RNA/ATP (important for energy
transfer) as well as phospholipids that form all cell
• Required by both plants and animals
• Limiting nutrient in many fresh water/marine food webs
Phosphorus Cycle
Phosphorus cycle (cont.)
Steps: *1. Weathering of uplifted rocks lead to phosphates on
land. (some phosphates go back to ocean)
*1: Phosphate mining leads to the creation and use of phosphate
fertilizers. Applied to fields (leaching) and can either run off into
streams, become part of soil pool, or be absorbed by plants
2:Excretion/decompostition release phosphates on land or in
3: Dissolved phosphates contribute to the ocean sediments.
They then begin to convert into phosphate rocks.
4: Geologic forces can slowly lift up phosphate rocks from the
ocean floor to form mountains.
Negative affects of Phosphorus
• To much phosphorus can negatively affect a
system, mostly marine systems. EX) The Algal
Human impacts on Cycle
• From the 1940’s trough 1900’s, phosphates used in laundry
detergents caused leached phosphorus emitions into streams,
rivers, and lakes.
• Fertilizers containing phosphorus lead to phosphates in water
1) Phosphorus is a major component of…?
2) Describe the steps of the phosphorus cycle
3) What is an Algal Bloom?
4) How do humans use phosphorus for agriculture?
5) Why is phosphorus a limiting nutrient in marine systems?
6) In the mid to late 1900’s, phosphates were used in…?
Work Cited
Friedland, A. (2011). Environmental science for ap. (1st
ed., pp. 71-72).
Algal bloom hit center stage. (2008, july 28). Retrieved from
The phosphorus cycle in 65 seconds. (September, 2009 20).
Retrieved from