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Ecology: Forest Food Webs Big Idea: Everything in nature is connected. You can’t change one part of an ecosystem without it having some effect – large.

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Presentation on theme: "Ecology: Forest Food Webs Big Idea: Everything in nature is connected. You can’t change one part of an ecosystem without it having some effect – large."— Presentation transcript:

1 Ecology: Forest Food Webs Big Idea: Everything in nature is connected. You can’t change one part of an ecosystem without it having some effect – large or small – on every other part.

2 The COE (Collection of Evidence) consists of at least 6 and at most 8 student tasks, all done on line.  Tasks show what you know and can do in relationship to state standards. Each task has 10-12 questions on different topics.  All tasks accessed from the inclusion bank in the online Education Data System (EDS) account.  A minimum of two tasks must be chosen as on-demand tasks – no changing answers after first time. The rest are extended-time tasks – you may go back and change answers later.  All tasks done by student alone. No help from others, no cheating.

3 Main Biology Topics: 1.Ecology: study of how living things interact with their environments. 2.Cell Processes: how all life processes happen at the cellular level. 3.Evolution/Genetics: how life on Earth has diversified and changed over time. 4.Inquiry and Application: How science is used to solve real problems in the real world beyond the classroom.

4 1.Suppose there was a decrease in the chipmunk population of the forest ecosystem shown below. Describe an effect this would have on another population of animals shown in the food web. In your description, be sure to - Identify a population from the food web diagram. - Describe an effect of decreased numbers of chipmunks on the identified population. Fewer coyotes because fewer chipmunks to eat. More green plants because fewer chipmunks eating them. More deer because fewer coyotes eating them.

5 2. What do you think would happen to the population of green plants eaten by mice if all the owls died or disappeared? Explain your answer. Population of green plants would decrease because more mice eating them, because no owls eating the mice. X

6 3. Unintended consequences are bad things that happen because of something we did, even though we didn’t expect or want those things to happen. Invasive species are animals or plants from elsewhere that tend to outcompete and kill off native species of animals or plants. Suppose people who kept snakes from outside Washington state as pets released them into the forest here because they didn’t want to take care of them anymore. Describe two unintended consequences that could happen as a result. Less food for native snakes because new snakes competing. Fewer native snakes because they fight with new snakes or get eaten by them. Could bring in diseases that could hurt or kill the native snakes.

7 les/2014/07/21/invasive-pythons- threaten-florida-everglades

8 predatory-lionfish-now-live-in-tampa-bay- 20141019/?utm_source=NCSnewsletters&utm _medium=email&utm_campaign=AM+News+ Mail “As with many invasive species, lionfish are in the wild because some were released by aquarium owners in the early 1980s, marine biologists say. The first Florida sighting came in 1985 in Dania Beach, near Fort Lauderdale. It wasn’t long before lionfish were spotted in the reefs of the Bahamas and then the rest of the Caribbean during the 2000s. Their range now extends from North Carolina to Pensacola in the Gulf of Mexico and all through the Caribbean.”

9 Worst invasive species of the Pacific NW? Himalayan blackberry

10 4. Nitrogen, a chemical element in our atmosphere, is needed by plants and animals to build cells and tissues. Using the Nitrogen Cycle diagram shown below, explain how nitrogen from the air gets into the cow’s body and how it goes back into the surrounding ecosystem. Nitrogen from air changed by bacteria in soil into form that plants take up through roots. Cow takes nitrogen in by eating plants. Through its poop, or when it dies and its body goes into the ground. Plants take it in from the ground through their roots.


12 5. The Department of Wildlife is considering the possibility of re-introducing grizzly bears into the North Cascades forest ecosystem. a. Describe two factors the Department of Wildlife officials should consider about the forests of the North Cascades before releasing grizzly bears there. How will grizzly bears affect bears already living there? How will grizzly bears affect populations of animals and plants they eat? Will they attack people?

13 5b. Ranchers in eastern Washington do NOT want the grizzly bears to be re-introduced because the bears have been known to kill cattle. What scientific information would be needed to solve the problem of how to protect the cattle without hurting the bears? How could that information be gathered? Do grizzlies attack cattle? How often? Look for records of attacks or start keeping them. Are there fences that will keep grizzlies out and cattle in? Try different fences and see.

14 5c. Describe three possible solutions to the problem, including any useful scientific concepts. Pay ranchers back for any cattle proven to be killed by grizzlies. Put bear-proof fences around cattle. Do electric fences work on grizzlies? Use guardian animals like dogs to bark when bears come. Will grizzlies kill dogs? Put shock collars on bears. How strong a shock can they take?

15 5d. A criterion is something that is used to measure the success of a proposed solution to a problem. Aside from the number of cattle killed by grizzly bears, what would be two other criteria biologists could use to evaluate possible solutions to the above problem? Number of grizzlies surviving. Number of grizzlies having cubs. Health of other animals and plants in the forest.

16 6. Sometimes biologists raise animals in captivity and release them into the wild to increase populations. Describe one unintended consequence of releasing orcas raised in captivity into the wild. In your response be sure to: - Describe one way orcas raised in captivity might differ from orcas in the wild. -Describe one impact of that difference on the ecosystem where the orcas are released. Orcas in captivity used to being fed by humans. Might have harder time catching prey in the wild. Orcas in captivity don’t interact with other orcas as much. Might not get along with own kind in the wild.

17 7. Using the Predator-Prey Populations graph shown below, explain how the population of prey affects the population of predators and vice versa. When prey population goes up, predator population goes up (more food for them). When predator population goes up, prey population goes down (more prey getting eaten).



20 8. Positive feedback loops are when changing one thing causes a continual increase or continual decrease in another thing. Negative feedback loops are when increasing one thing causes an alternating increase and decrease of the other thing. Is the predator-prey relationship shown below a positive or negative feedback loop? Explain your answer. Negative feedback. Populations going up and down instead of just up or just down.

21 Positive feedback loop: Both populations only increase or only decrease.

22 Negative feedback loop: Both populations increase and decrease.

23 Video: Positive & Negative Feedback Loops neutel?utm_source=TED-Ed+Subscribers&utm_campaign=d8af586ac0- 2013_09_219_19_2013&utm_medium=email&utm_term=0_1aaccced48-d8af586ac0- 46516589

24 Questions…?



27 Get a computer and start logging on….

28 Plagiarism video

29 1. Take out this assignment to review. 2. Get a computer and start logging on……

30 9. Suppose a new species of owl was introduced to the forest ecosystem. Describe two conditions in the forest ecosystem that might allow the new owl population to increase rapidly. Many animals for them to eat. Few predators eating them.

31 10. Limiting factors = things that can limit the growth of animal or plant populations in a particular area. Describe two ways an increase in one owl population could limit the population of another owl species in the forest ecosystem. Competition for food, nesting sites



34 11. What conditions do plant populations need to grow rapidly? Water, light, soil. Not a lot of animals eating them. Not a lot of other plants competing for space.

35 12. Describe two ways an increase in one tree population could limit the growth of another tree population in the forest ecosystem. Competition for sunlight, soil, water.

36 Today’s task: DIY Plant Experiment, question 3 Helpful Hint: Include wording from the question in your answer to make sure you’re answering the question!

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