1. NOTES: Biogeochemical Cycles

2. On Earth. .. Matter can occasionally come, but it cannot just “leave”.
WE call this a closed system.

3. Because matter stays on earth, that means that elements are shuffled from place to place. These are called BIOGEOCHEM-ICAL CYCLES.

4. Some Major Cycles of Matter
Water / Hydrologic Cycle (O2)
Rock Cycle
Chemical Cycles
Carbon
Nitrogen

5. Pathways (arrows) indicate movement
Pathways (arrows) indicate movement. Reservoirs = Places where large amounts of an element are stored
Atmosphere
Biosphere
Lithosphere
Hydrosphere

6. Carbon Cycle
Atmosphere
Biosphere
Lithosphere
Hydrosphere

7. Carbon Cycle Reservoirs (the largest is the lithosphere!)
Atmosphere 1x
(= g)
Biosphere 3x
55x
35,000x
Lithosphere
Hydrosphere

8. Carbon Cycle Atmosphere Biosphere Lithosphere Hydrosphere
Respiration& Decay
Photosynthesis
Dissolution
Weathering
& Volcanism
Evaporation
Biosphere
Burial &
Lithification
Lithosphere
Photosynthesis
Burial &
Lithification
Hydrosphere

9. Human Impacts Atmosphere Biosphere Net Effect: Increase in Carbon
Deforestation:
Decrease Photosynthesis
Increase Respiration
Atmosphere
Burning fossil fuels:
Increased combustion
Biosphere
Net Effect:
Increase in Carbon
in Atmosphere
Lithosphere
Hydrosphere

10. Which of the earth’s sphere’s contains the largest reservoir of CARBON?

11. Humans are tampering with the closed system of Carbon on earth (and adding more, which can affect the climate)

12. BIOMASS = Biomass, a renewable energy source, is biological material from living, or recently living organisms, such as wood, waste, (hydrogen) gas, and alcohol fuels.
FOSSIL FUELS are fuels formed by natural resources such as anaerobic decomposition of buried dead organisms. The age of the organisms and their resulting fossil fuels is typically millions of years, so it is a non-renewable energy source.

13. Nitrogen fixation is a process where Nitrogen in nature (N2) is converted to Ammonia (NH3). This makes it a “useable” / non-toxic compound for living things to put into sugars, proteins, and DNA.
Root “nodules” and bacteria and lightning can do this!

14. Nitrogen Cycle Atmosphere = RESERVOIR Biosphere Lithosphere
Denitrification:
bacteria
Biosphere
Nitrogen fixation:
bacteria
lightning
Absorption
Waste & Decomposition
Erosion
Lithosphere
Hydrosphere

15. Human Impacts Atmosphere Biosphere Net Effect: Increase in Nitrogen
in water & soil
industrial (fertilizer)
combustion
Increased Erosion from construction
Lithosphere
Hydrosphere

16. Oxygen gets cycled chemically through the Water / Hydrologic Cycle mostly, but also from. . .

17. The process of Photosynthesis (food-making) and Cellular Respiration (food-breaking) between plants and other organisms

18. Where is the ultimate mixing location (interface) for ALL of the cycles?
SOIL!

19. CLIMATE is affected greatly by biogeochemical cycles, since these elements can be mixed with the atmosphere. Addition/deletion of any atmospheric gas can change temperature and reactivity.