Biogeochemical Cycles

All matter cycles…and all cycles matter!

Carbon CycleCarbon Cycle

Carbon moves between the living & nonliving parts of the ecosystem

2 major driving forces: Photosynthesis (plants take CO2 in) Cellular respiration (releases CO2)

SINKS take IN carbon and store itSINKS take IN carbon and store it

Plants take in carbon dioxide during Plants take in carbon dioxide during photosynthesis and release oxygenphotosynthesis and release oxygen

Oceans (especially cold water) & Earth’s Oceans (especially cold water) & Earth’s crustcrust

Living things during respiration

Combustion (burning fossil fuels)

Fires

Electricity

SOURCES release carbon OUT into SOURCES release carbon OUT into the atmospherethe atmosphere

Climate Change

carbon sinks & sources should be balanced, but they aren’t

too many carbon sources greenhouse effect becomes too strong

Greenhouse effect = heat is trapped in by gases

Check for Understanding

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

Nitrogen CycleNitrogen Cycle

Nitrogen moves between the living & nonliving parts of the ecosystem

Nitrogen fixationNitrogen fixation

Nitrogen gas (N2) is changed into ammonia by nitrogen-fixing bacteria

Legume plants (beans) have lots of these good bacteria on their roots

YouTube

Nitrogen Fixation – Seven Wonders of the Microbe World

Check for Understanding

Where do we get most of our nitrogen from?

The atmosphere Food we eat Eating fertilizer The ocean