1. Phosphorus cycle Objectives Explore the phosphorus cycle.
Understand how phosphorus can be added or lowered in different environments.
Outcomes
3: Construct a phosphorus cycle
5: Explain how phosphorus levels in an environment may be altered.
7: Use knowledge of cycles and data analysis skills to complete questions into nutrient cycles.
Key terms: phosphorus, phosphate, agriculture, cycle.

2. Phosphorus cycle

3. PROTOPLASM
Plants
Animals
Bacteria
Excretion
Protoplasm Synthesis
Phosphate Rocks
Guano Deposits
Bones, Teeth
Fossil Bone Deposits
Phosphating Bacteria
Volcanic Apatite
Erosion
Marine Birds and fish
DISSOLVED PHOSPHATES
Loss deep sediments
Shallow Marine Sediments
In this figure, phosphorus, an important and necessary constituent of protoplasm, tends to “circulate,” the organic compounds being broken down eventually to phosphates which are again available to plants. The great reservoir of phosphorus is not the air, however, but the rocks or other deposits which have been formed in the past geological ages. These are gradually eroding, releasing phosphates to ecosystems, but much phosphate escapes into the sea, where part of it is deposited in the shallow sediments and part of it is lost to the deep sediments. The means of returning phosphorus to the cycle may presently be inadequate for the loss.

4. Phosphorus cycle
How could the levels of phosphorus in an ecosystem be altered?
Are these biotic or abiotic factors?
How can we minimise these changes if they are problematic?
Outcomes
3: Construct a phosphorus cycle
5: Explain how phosphorus levels in an environment may be altered.
7: Use knowledge of cycles and data analysis skills to complete questions into nutrient cycles.
Key terms: phosphorus, phosphate, agriculture, cycle.

5. Phosphorus cycle
Sea birds – have apparently played an important role in returning phosphorus to the cycle. Example: Guano deposits on the coast of Peru
Man hastens the rate of loss of phosphorus because of too much harvest of marine fish.
Man is more concerned with the “traffic jam” of dissolved phosphate in the waterways resulting from increased “erosion” that cannot be compensated for by “protoplasm synthesis” and “sedimentation”.
Outcomes
3: Construct a phosphorus cycle
5: Explain how phosphorus levels in an environment may be altered.
7: Use knowledge of cycles and data analysis skills to complete questions into nutrient cycles.
Key terms: phosphorus, phosphate, agriculture, cycle.

6. Key terms: phosphorus, phosphate, agriculture, cycle.
Phosphorus cycle
Key terms: phosphorus, phosphate, agriculture, cycle.