1. Nutrient Cycles Certain materials are cycled through ecosystems to be used over and over, they are called nutrients Certain materials are cycled through ecosystems to be used over and over, they are called nutrients Examples of these nutrients are carbon, nitrogen and phosphorus Examples of these nutrients are carbon, nitrogen and phosphorus When we disrupt these cycles we affect the ecosystems that they are a part of When we disrupt these cycles we affect the ecosystems that they are a part of

2. The Carbon Cycle Carbon is an essential element for all organisms. It is found in different forms in all four spheres of the earth. Six factors contribute to its cycling: 1. Photosynthesis - Plants use sunlight to “capture” carbon dioxide from the atmosphere (as CO 2 ) to make sugars. The chemical reaction is: light + 6CO 2 + 6H 2 O  C 6 H 12 O 6 + 6O 2 light + 6CO 2 + 6H 2 O  C 6 H 12 O 6 + 6O 2 (Sun’senergy) (carbon dioxide from the air) (waterfrom the soil) (produces) (sugar to make leaves…) leaves…) (oxygenreleased to the air)

3. 6 Factors that contribute to the carbon cycle 2.Respiration – Process by which animals and plants (in the dark) use sugars to make energy and CO 2.The chemical reaction is: C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O + energy C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O + energy (sugars from food) (breath it in) (breath it out) (water in the body) (needed grow, move…) What do you notice about these two reactions? Answer: They are opposite! Plants produce the sugars and oxygen that animals need. Animals need plants to survive.

4. 6 Factors that contribute to the carbon cycle 3.Food Chain: Carbon is also passed on from producers to consumers and moves up the food chain. 4.Decay: Decomposers break down dead plant and animal material. Some of the carbon is released as CO 2 into the atmosphere some of it enters the ground.

5. 6 Factors that contribute to the carbon cycle 6.Carbon reservoirs: Carbon is stored in different parts of earth’s four spheres (eg. much CO 2 is dissolved in the oceans, carbon is stored in the earths crust as coal and fossil fuels) 5.Combustion: During the combustion of fossil fuels (oil, gasoline, natural gas) and forest fires, CO 2 is released into the atmosphere.

6. Human impact on the carbon cycle How have humans impacted the carbon cycle? What are the consequence of this?

7. Diagram of the carbon cycle