HOW ECOSYSTEMS WORK

1. HOW ECOSYSTEMS WORK

2. Energy Flow in Ecosystems • Life depends on the sun. 6 CO2 6H2O Solar energy C6H12O6 6O2

3. Energy is transferred Consumers Producer

4. Definition: • Producer: an AUTOTROPH (means self-feeder) –it makes it’s own food through photosynthesis or from chemical sources • Consumer: an organism that gets it’s energy from eating other organisms.

5. There are 4 types of consumers: • Herbivore- energy from producers • Carnivore- energy from other consumers • Omnivore – energy from both producers and consumers • Decomposer- energy from breaking down dead organisms in an ecosystem and returns nutrients to soil, water, and air.

6. What am I?

8. Cellular Respiration • The process by whichfoodisbroken down to yieldenergy. (Occursinside the cells.) C6H12O6 6O2 6 CO2 6H2O Energy

9. Food chain • It’s a sequence in which energy is transferred from one organism to the next as each organism is eaten by another.

10. Food Web • Shows many feeding relationships that are possible in an ecosystem.

11. Trophic Levels • Each step in the transfer of energy in the food chain or web in an ecosystem is a trophic level. • Each time energy is transferred from one organism to the next, some energy is lost as heat and via cellular respiration. • 90% of the energy is used by the • organism for living. • 10% of the energy becomes part • of it’s body stored in it’s molecules. • That 10% is available to the next • trophic level.

12. Energy Pyramids

13. The Carbon Cycle • The process by whichcarboniscycledbetween the atmosphere, land, water and organisms. • There is a short term cycle and a long term cycle. http://www.youtube.com/watch?v=2Jp1D1dzxj8

14. Summary: Carbon Cycle • CO2 in the atmosphere is used by producers to produce carbohydrates. • Consumers eat the producers and obtain the carbon from carbohydrates. • As consumers break down the food via cellular respiration, some of the carbon is released back to the atmosphere as CO2. • Some of that atmospheric CO2 dissolves in water. • The other carbon is stored in the bodies of the animals who eat it. When they die it can be released into the soil or air. • After a long period of time, the decomposition of dead matter forms deposits of natural gas, oil or coal. (fossil fuels) • Question: How do we affect the Carbon Cycle?

15. Nitrogen Cycle • All organisms need nitrogen to build proteins. • Nitrogen makes up 78% of our atmosphere. • Problem: Most organisms cannot use atmospheric nitrogen. • It must be altered or “fixed” before it can be used. • The ONLY organisms that can do this are a few species of bacteria known as Nitrogen-fixing bacteria. • They take nitrogen from the air and transform it into molecules that living things can use. • The Nitrogen cycle is simply: the process in which nitrogen is cycled between the atmosphere, bacteria and other organisms.

17. Ecological Succession • Is the gradualprocess of change and replacement of the type of species in a community. • This cantakehundreds or thousands of years.

18. Primary Succession: • Occurs on a surface where no ecosystem existed before. • Ex. Rocks, cliffs, sand dunes • Secondary succession: • Occurs on a surface where an ecosystem has existed. • Occurs in ecosystems that have been disturbed of disrupted. • Ex. Humans, animals, storms, floods, earthquakes, volcanoes

19. http://www.youtube.com/watch?v=dBm9kTSrxio • Secondary succession: • After the eruption at Mount St. Helens, in Washington State the first plants that began to colonize were called pioneer species. • Over time, pioneer species make the area habitable again for other species. Before eruption 1980 After eruption 1980

20. One year later Ten years later

21. Mount St Helens today, still recovering If these organisms continue to grow, over time they will form a climax community, a final and stable community.