Biogeochemical Cycles

1
Biogeochemical Cycles
All matter cyclesand all cycles matter!
2
Carbon Cycle

• Carbon moves between the living nonliving parts
  of the ecosystem
• 2 major driving forces
• Photosynthesis (plants take CO2 in)
• Cellular respiration (releases CO2)

3
SINKS take IN carbon and store it

• Plants take in carbon dioxide during
  photosynthesis and release oxygen
• Oceans (especially cold water) Earths crust

4
SOURCES release carbon OUT into the atmosphere

• Living things during respiration
• Combustion (burning fossil fuels)
• Fires
• Electricity

5
Climate Change

• carbon sinks sources should be balanced, but
  they arent
• too many carbon sources ? greenhouse effect
  becomes too strong
• Greenhouse effect heat is trapped in by gases

6
Check for Understanding

• Which of the following is the best carbon sink?
• Burning fossil fuels
• Really hot water
• The ocean
• Small rocks

7
Nitrogen Cycle

• Nitrogen moves between the living nonliving
  parts of the ecosystem

8

• Nitrogen fixation
• Nitrogen gas (N2) is changed into ammonia by
  nitrogen-fixing bacteria
• Legume plants (beans) have lots of these good
  bacteria on their roots

9
YouTube

• Nitrogen Fixation Seven Wonders of the Microbe
  World

10
Check for Understanding

• Where do we get most of our nitrogen from?
• The atmosphere
• Food we eat
• Eating fertilizer
• The ocean