1. Ecology Part 6 Carbon & Nitrogen Cycles R. Martinez, 2012

2. What is Carbon? An element The basis of life on earth Also found in rocks, oceans, atmosphere

3. Carbon is recycled The same carbon atoms are used repeatedly on earth. They cycle between the earth and the atmosphere. biotic abiotic

5. How does carbon move? Photosynthesis - CO 2 is taken from the air and trapped into food (glucose) Cellular Respiration - CO 2 is returned to the atmosphere when food (glucose) is broken down absorb CO 2 make sugar eat sugar release CO 2 Plants absorb CO 2 and make sugar while consumers eat sugar and release CO 2. It makes a cycle – the carbon cycle!

6. The Role of the Decomposer

8. What happens when we disrupt a cycle? Without plants, carbon dioxide would build up in the atmosphere and the amount of oxygen available to animals would be reduced. Any disruption to a cycle leads to the ENTIRE cycle being affected. Any disruption to a cycle leads to the ENTIRE cycle being affected.

9. What is Nitrogen? 79% of the atmosphere is nitrogen gas but it is in a form most living things cannot use. N 2 freenitrogen

10. Why do we need Nitrogen? Our DNA, RNA, and PROTEINS all REQUIRE NITROGEN!

11. How do we get Nitrogen? Nitrogen fixation is N 2  NH 3 (ammonia) Nitrogen-fixing bacteria convert nitrogen into ammonia/nitrates. Plants absorb nitrates. Animals eat plants. N 2 in air nitrogen-fixing bacteria NITRATES

12. Nitrogen Fixation normal conditions. Nitrogen fixation can also be caused by lightning!

13. How does Nitrogen return to the atmosphere? Denitrifying bacteria convert the nitrates back into nitrogen.

14. When plants and animals die, the nitrogen contained in these organisms is digested by decomposers and released into the soil as ammonia. Without these decomposers, the nitrogen would remain trapped in the dead animals. These decomposers recycle the nitrogen and are a key component of the cycle. The Role of the Decomposer

15. The Nitrogen Cycle

16. Fish death due to depleted oxygen While too little nitrogen can be a problem, too much nitrogen can also cause problems. When fertilizers containing nitrogen get into the water supply, they can make it too easy for microorganisms like bacteria and plankton to grow. These organisms deplete the water of oxygen. With this oxygen gone, aquatic and marine life suffer and often die because they do not have the O 2 they need. What happens when we disrupt a cycle? Any disruption to a cycle leads to the ENTIRE cycle being affected. Any disruption to a cycle leads to the ENTIRE cycle being affected.