1. What is meant by the word CYCLE?
Nutrient Cycles
What is meant by the word CYCLE?

2. Nutrient Cycles Nutrients are available in fixed quantities on earth
The same nutrients are passed from one organism to another over and over again

3. What are Nutrient's?
Nutrients: a substance that promotes growth and health in living organisms. What nutrients do humans need for growth and well-being?

4. Nutrient Cycles
Passing NUTRIENTS from one organism to another (eating)

5. How do nutrient cycles differ from energy flows?
Passing NUTRIENTS from one part of the biosphere to another through a pathway called nutrient cycles
How do nutrient cycles differ from energy flows?

6. How do Nutrient Cycles differ from Energy Flows?
Nutrient cycles move the same nutrients over and over again through the biosphere, whereas energy flows in only 1 direction and does not recycle.

7. Visualizing Nutrient Cycles
What nutrients are recycled?
Water
Nitrogen
Carbon

8. Water Cycle
Consists of processes called: - evaporation condensation precipitation

9. Lets Start with the SUN’S effect on Water:
Evaporation: The SUN heats up liquid water on the Earth’s surface causing it to change liquid to a gas, called water vapor that rises into the atmosphere.
Condensation: When the vapor is cooled at high atmospheric levels, it condenses, or changes its state back to liquid water.
Precipitation: Tiny droplets of water collect and fall to the earth as rain, snow, sleet, or hail depending on the air temperature.
The cycle then repeats

10. Nitrogen Cycle

11. Nitrogen Cycles Nitrogen is the most abundant gas in the atmosphere.
About 80% of the atmosphere is nitrogen gas
Nitrogen gas is unusable by most plants and cannot directly enter an ecosystems nutrient flow.
Bacteria in the soil converts nitrogen gas to a usable form and makes it available to plants.
As a result, nitrogen becomes available to the animals that eat the plants (that would be YOU).

12. Question
Have you ever noticed sooty black material that is left over when a piece of paper or wood burns?

13. Carbon Cycle

14. Answer: Carbon
Most of the carbon in the atmosphere is in the form of carbon dioxide.
The amount of carbon dioxide returned to the atmosphere by breathing (respiration) balances the amount removed by plants (photosynthesis).
Plants use carbon dioxide and animals produce carbon dioxide (this exchange occurs equally).
HOWEVER, the burning of fossil fuels increases the amount of carbon dioxide released into the atmosphere, destroying this natural balance.

15. The Result: The Greenhouse Effect
Human Activity has returned carbon that has been stored in sedentary rock for millions of years into the atmosphere. Who thinks this is a good thing? How has the carbon been “returned”?

16. Greenhouse Effect
Has anyone ever gone into a greenhouse before? What causes the greenhouse to be warmer than the outside temperature?

17. Answer
The glass allows the sun’s energy to enter the greenhouse where it is transformed into heat energy.
The glass does not allow the heat energy to leave the greenhouse.
The trapped energy causes the temperature to rise.
So what does this relate to the carbon cycle?

18. The Greenhouse Effect
Gases like carbon dioxide, trap energy in the atmosphere just as the glass in a greenhouse traps heat inside the greenhouse.
Atmospheric carbon dioxide allows the sun’s energy to reach the Earth’s surface where it is converted to heat energy.
Heat energy radiates back into outer space.
HOWEVER, carbon dioxide and other gases in the atmosphere absorb some of this heat and forms a “heat trap” around the earth.

19. Greenhouse Effect

20. The Result
The presence of greenhouse gasses heat the planet faster than it can cool.
Without greenhouse gasses the planet would be 30 degrees cooler.

21. How do Human Activities Affect the Environment?