1. The Phosphorus Cycle

2. Phosphorus is essential to living organisms. WHY???
Cell Membranes
Energy-storing Molecules
Lipids (Fats and Oils)
ATP and ADP
Phosphorus is essential to living organisms. WHY???
DNA & RNA
Combines w Calcium to form BONES and TEETH
Helps Metabolize Carbs, Fats, and Proteins

3. Phosphorus is located in…
Sediments
Rocks
Water
Soil
Living
Organisms

4. Phosphorus Cycles through all parts of an ecosystem, but...
Hydrosphere
Biosphere

5. Most phosphate is LOCKED in SEDIMENTS & ROCKS. It is a very slow cycle.
Most Phosphorus is UNAVAILABLE to Plants…
BACTERIA convert useable phosphate into ORGANIC forms that plants can’t use.
ADSORPTION- INORGANIC phosphorus can be chemically bound to soil particles, making it unavailable to plants.
pH: INORGANIC phosphorus compounds need to be SOLUBLE to be taken up by plants.
If soil is too acidic or too basic, Phosphorus will bond with other compounds, making it less available to plants.
pH <4 or >8

6. Key Steps of the Phosphorus Cycle…
WEATHERING & EROSION cause rocks to release (INORGANIC) phosphate ions, which is distributed in soils and water.
and water

7. Key Steps to the Phosphorus Cycle…
PLANTS take up INORGANIC phosphate from the soil and water.
Animals eat plants
Phosphate is used in ORGANIC molecules, like DNA, ATP
Organism DIES (or produces WASTE) and ORGANIC phosphate returns to the soil.
and dead organisms

8. Key Steps to the Phosphorus Cycle…
In the SOIL, BACTERIA breakdown matter to INORGANIC phosphorus, which PLANTS can use. This is called MINERALIZATION

9. Key Steps to the Phosphorus Cycle…
Phosphorus in the SOIL runs off into WATER and eventually OCEANS.
It becomes part of SEDIMENTS over time.

10. How Do We Impact the Phosphorus Cycle?
Mining (for fertilizer and detergents)
Depletes resources (takes millions of years to replenish)
Deforestation
slash and burn clearing land for agriculture decreases available amounts. (held in trees and vegetation, not soil)
Waste
Agricultural and human waste contains high amounts of phosphorus, even when treated.

14. 5 2 8 7 1 3 1 6 2 4 ANIMAL DIES RETURNING ORGANIC PHOSPHORUS TO SOIL
EROSION 8
EUTROPHICATION 7 1
LEACHING
PLANTS TAKE UP INORGANIC PHOSPHATE FROM SOIL 3 1
WEATHERING
ANIMAL WASTE RETURNS ORGANIC PHOSPHORUS TO SOIL 6 2
ANIMALS EAT
PHOSPHATE USED TO BUILD ORGANIC MOLECULES (DNA & PROTEINS 4