Phosphorus cycleObjectives

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.

Phosphorus cycle

PROTOPLASMPlants Animals

Bacteria Excretion

Bones, TeethPhosphating

Bacteria

Phosphate RocksGuano Deposits

Fossil Bone Deposits

Volcanic Apatite

Erosion

DISSOLVED PHOSPHATES

Shallow Marine Sediments

Loss deep sediments

Marine Birds and fish

Protoplasm Synthesis

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.

Phosphorus cycleHow 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.

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.

Phosphorus cycle

Key terms: phosphorus, phosphate, agriculture, cycle.