1. Water, Carbon, Nitrogen Oxygen and Phosphorus
Cycles
Water, Carbon, Nitrogen Oxygen and Phosphorus

2. Water (hydrologic) Cycle
Plants absorb water from the soil
Transpiration and respiration return water to the atmosphere
Precipitation returns water to the soil
Nonmetal oxides in the atmosphere combine with water to form acid rain

4. The Carbon Cycle Carbon is fixed by plants
6 CO H2O  C6H12O6 + 6 O2
Carbon is given off by consumers
C6H12O6 + 6 O2  6 CO2 + 6 H2O
Organisms containing carbon form fossil fuels
Burning fossil fuels releases carbon
2 C8H O2  16 CO H2O

5. Carbon Cycle

7. Arctic Carbon Cycling

8. The Nitrogen Cycle Bacteria fix nitrogen from the air
Consumers and producers incorporate nitrogen into their tissues
Nitrogen can be fixed industrially from the air
Production of ammonia
Decay processes return nitrogen to the air
Nitrogen from fertilizers may contaminate water sources

10. Aquarium Nitrogen Cycle

11. The Oxygen Cycle Oxygen is produced by photosynthesis
6 CO2 + 6 H2O  C6H12O6 + 6 O2
The largest chemical process on earth!
Oxygen is sequestered by respiration
C6H12O6 + 6 O2  6 CO2 + 6 H2O

12. C6H12O6 + 6 O2  6 CO2 + 6 H2O
6 CO2 + 6 H2O  C6H12O6 + 6 O2

13. The Phosphorus Cycle
The element phosphorus (P)is released in the form of ionic phosphate (PO43-)
Weathering of rock, mining, some detergents and fertilizers
Phosphate is taken up by plants and fungi
Consumers absorb phosphate from plants
Decomposers return phosphate to soil
Phosphate leaches into water supply
May form new phosphate containing rock