1. Biogeochemical Cycles: Water, Carbon, Nitrogen and oxygen

2. The Water Cycle (Hydrologic Cycle) :
The water cycle involves the movement of water back and forth from Earth’s surface to the atmosphere.
Remember water can exist in 3 states: Solid, Liquid, and Gas

3. The Water Cycle: 3 basic Steps
Water on the Earth’s surface is heated by the sun and evaporates.
Water rises into the upper atmosphere, cools, condenses, and forms clouds.
Water falls back to the surface as precipitation (rain, snow, sleet, or hail).

4. The Water Cycle: Key concepts
Most precipitation falls back into the oceans, lakes, rivers, and streams.
Water in the atmosphere is completely replaced once every 8 days
Water on this planet can be stored in any one of the following reservoirs: atmosphere, lakes, rivers, oceans, groundwater, soil, and/or glaciers.

5. The Hydrologic Cycle

6. The Carbon and oxygen Cycle

7. The Carbon/Oxygen Cycle: Photosynthesis
Photosynthesis - Plants use carbon dioxide (CO2) along with water and sunlight to produce glucose (sugar) and release oxygen
6H2O + 6CO C6H12O6 + 6O2

8. The Carbon/Oxygen Cycle: Respiration
Respiration - Both plants and animals break down glucose (sugar) during respiration to obtain energy.
C6H12O6 + 6O H2O + 6CO2
glucose + oxygen
water + carbon dioxide

9. The Carbon/Oxygen Cycle: Consumption
Consumption: During their lifetime, animals pass along organic compounds from one another through feeding. Wastes produced during their lifetime are broken down by decomposers such as fungi and bacteria and carbon dioxide is added to the atmosphere.

10. The Carbon/Oxygen Cycle: Decomposition
Decomposition - When living things die, these decomposers break down their organic compounds. Here again carbon dioxide is returned to the atmosphere.

11. The Carbon/Oxygen Cycle: Combustion
Combustion: Any burning of fossil fuels (Oil, coal, natural gas) or wood…... or combustion releases the energy stored in these organic compounds and also large amounts of carbon dioxide

12. The Carbon/ Oxygen Cycle

13. The Nitrogen cycle: Key Concepts
Plants and animals (all living things) need nitrogen to make proteins.
Plants cannot absorb nitrogen (N2) from the air.
Bacteria in the soil convert unusable (N2) from the air into nitrates (NO3) that plants can use to make their proteins.
Animals eat plants to get their proteins.

14. The
Nitrogen
Cycle

15. Acid rain is part of the nitrogen cycle