BIOGEOCHEMICAL CYCLES
Water Cycle
Carbon Cycle
Nitrogen Cycle
General Model of Nutrient Cycling
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1. Producers incorporate chemicals from the abiotic
reservoir (where a chemical accumulates or is stockpiled
outside of living organisms) into organic compounds.
2.Consumers feed on the producers, incorporating some of
the chemicals into their own bodies.
3. Both producers and consumers release some chemicals
back to the environment in waste products (CO2 and
nitrogen wastes of animals)
4. Detritivores play a central role by decomposing dead
organisms and returning chemicals in inorganic form to the
soil, water, and water.
5. The producers gain a renewed supply of raw materials,
and the cycle continues.
General Model of Nutrient Cycling
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PLEASE REMEMBER, NUTRIENTS ARE RECYCLED IN AN
ECOSYSTEM, BUT ENERGY IS LOST FOR LIVING
ORGANISMS AT THE END OF THE FOOD CHAIN.
Water Cycle
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1.Precipitation
2.Condensation (conversion of gaseous water vapor into liquid water)
3. Rain Clouds
4. and 5. Evaporation (conversion of water to gaseous water vapor) from ocean
6. and 7. precipitation over ocean
8. evaporation from land
9. Transpiration
10. Transpiration
11. evaporation from lakes, rivers
12. surface runof
13. infiltration (movement of water into soil)
14. Water locked in snow
15. Precipitation to land
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**refer to diagrams in handout
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Water Cycle
Carbon Cycle
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1. Carbon in plant and animal tissues
2. fossilization (preserved remains or traces of animals, plants, and other organisms)
3. Death and excretion
4. Decomposers (breakdown organic materials to inorganic ones)
5. coal
6. photosynthesis
7. atmospheric CO2
8. Dissolving
9. combustion (burning of wood and fossil fuels)
10. diatoms (major group of algae, and are one of the most common types of phytoplankton)
11. drilling for oil and gas
12. fossilization
13. oil and gas
14. limestone
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**refer to diagrams in handout
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Carbon Cycle
Nitrogen Cycle
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1. Nitrogen in plant and animal tissue
2. Excretion
3. Ammonia (NH3)
4.Dead organisms
5. decomposers
6. Nitrifying bacteria (convert ammonia to nitrate)
7. nitrogen fixing bacteria (convert N2 to ammonia)
8. nitrate (NO3-)
9. nitrate (NO3-) available to plants
10. swampy ground
11. denitrifying bacteria (return fixed nitrogen to the atmosphere)
12. lightning (atmospheric nitrogen fixation)
13. atmospheric nitrogen (N2 gas)
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**refer to diagrams in handout
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Nitrogen Cycle