1. Environmental Science Chapter 3 Notes #2

2. Energy Flow in Ecosystems  Producer /Consumer  Almost all organisms get their energy from the sun  Herbivore/ Carnivore/ Omnivores/ Decomposers  photosynthesis  6CO 2 + 6H 2 O + light energy  C 6 H 12 O 6 + 6O 2  Cellular respiration  C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O + energy  Food Chain  Food Web  Energy Pyramid  Trophic Levels

3. The Cycling of Materials There are 3 main cycles that allow for the reuse of materials  The Water Cycle  The Carbon Cycle  The Nitrogen Cycle

4. The Cycling of Materials  The Water Cycle  The sun provides energy that drives the water cycle  Heat evaporates water, cools in the atmosphere, and becomes tiny droplets in clouds  The clouds meet cold air & the water comes back to earth as precipitation  Precipitation may evaporate again or become part of rivers, streams, lakes, etc, or soak into the soil  There it gets used by plants or becomes groundwater  It hits rock where it can’t go any further

5. The Cycling of Materials

6.  The Carbon Cycle  Carbon is an essential component to fats, carbs, proteins  It enters the ecosystem when plants take in CO2 during photosynthesis  Consumers eat producers, they obtain carbon  Consumers break down food, releasing carbon as CO2  Photosynthetic organisms also release CO2 during cellular respiration  Our effect on the cycle  We burn fossil fuels (remains filled with carbon)  Carbon gets released into the atmosphere

7. The Cycling of Materials

8.  The Nitrogen Cycle  All organisms need Nitrogen to build proteins  N makes up 78% of the atmosphere  The only organisms that can use Nitrogen directly are called Nitrogen-fixing bacteria  All other organisms are dependent on these for their nitrogen  They “fix” it into a form that ecosystems use  These bacteria live within the roots of certain plants (clover, beans, etc.) and in the soil

9. The Cycling of Materials  They have a mutualistic relationship with these plants  They use sugar from the plants  The bacteria produces Nitrogen  Animals get N by eating the plants  Decomposers break down Nitrogen containing wastes, returning the N to the soil, then bacteria convert it to a gas, which returns to the atmosphere  Once N is in the ecosystem is cycles in a loop between organisms and the soil.

10. The Cycling of Materials

11. Assignments  Chain/Web/Pyramid Due on Monday  Section 1 Review ws due- Monday  Transparency Worksheets 6-8 = due on Wednesday  Test on Chapter 3 Next Week (Tuesday)