Biogeochemical Cycles

1
Biogeochemical Cycles

• Water Cycle
• Carbon Cycle
• Nitrogen Cycle

2
General Model of Nutrient Cycling

• 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.

3
General Model of Nutrient Cycling
4

• PLEASE REMEMBER, NUTRIENTS ARE RECYCLED IN AN
  ECOSYSTEM, BUT ENERGY IS LOST FOR LIVING
  ORGANISMS AT THE END OF THE FOOD CHAIN.

5
Water Cycle

• 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
• refer to diagrams in handout

6
Water Cycle
7
Carbon Cycle

• 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
• refer to diagrams in handout

8
Carbon Cycle
9
Nitrogen Cycle

• 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)
• refer to diagrams in handout

10
Nitrogen Cycle