Nutrient Cycles 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 When we disrupt these cycles we affect the ecosystems that they are a part of

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: Photosynthesis - Plants use sunlight to “capture” carbon dioxide from the atmosphere (as CO2) to make sugars. The chemical reaction is: light + 6CO2 + 6H2O  C6H12O6 + 6O2 (oxygen released to the air) (sugar to make leaves…) (Sun’s energy) (carbon dioxide from the air) (water from the soil) (produces)

6 Factors that contribute to the carbon cycle Respiration – Process by which animals and plants (in the dark) use sugars to make energy and CO2.The chemical reaction is: C6H12O6 + 6O2  6CO2 + 6H2O + 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.

6 Factors that contribute to the carbon cycle Food Chain: Carbon is also passed on from producers to consumers and moves up the food chain. Decay: Decomposers break down dead plant and animal material. Some of the carbon is released as CO2 into the atmosphere some of it enters the ground.

6 Factors that contribute to the carbon cycle Combustion: During the combustion of fossil fuels (oil, gasoline, natural gas) and forest fires, CO2 is released into the atmosphere. Carbon reservoirs: Carbon is stored in different parts of earth’s four spheres (eg. much CO2 is dissolved in the oceans, carbon is stored in the earths crust as coal and fossil fuels)

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

Diagram of the carbon cycle