1. Keystone Species Notes
Write or draw what’s in red

2. Review…
Which one if more realistic?
Which one has more biodiversity?

3. What is biodiversity? (Write whats in red)
Biodiversity: the variety of animal/plant species in a specific area
Why is biodiversity important?
The more biodiversity an ecosystem has the STRONGER the ecosystem is in response to changes
Grasshopper population reduced
Frogs and Pythons die off
Grass takes over
Ecosystem cannot recover and forever changed
Food chain

4. Rats population decreases
Results?
More grasshoppers
Less corn
Wolf, python, and eagle eat more of other species
In a food web: Ecosystem changes but it can recover if initial population increases back to normal levels (write down)

5. Draw this picture
In this ocean ecosystem & food web, this starfish (Pisaster) is the top predator & is also known as the area’s KEYSTONE species
What do you think will happen if Pisaster is removed?
Chitons= 8 sectioned, flexible cousins to clams
Limpets=
Wide shelled water snails
Mussel= 2 sections, elliptical clam
Barnacles= non-mobile suspension feeders, cousins to crabs & lobsters

6. What happened? (read only)

7. Put “x” on the eliminated organisms:
Diversity in tide pools is greatly reduced!
Barnacles (acorn & goose) & mussels (bivalve Mytilus) take over the entire ecosystem (because they reproduce & grow faster than chitons and limpets)
Snails population increases as well X X X

8. Food chain vs. food web
Food chain = weak
Food web = strong
Food webs have more biodiversity & so are stronger than food chains
Biodiversity = a total of all the organisms living in an area
The more biodiversity, the stronger the ecosystem
-think of how hard it is to remove a spider web if you walk through one!

9. So what? (write only what is in red)
The tide pools have less diversity and I should care why?
If another ecological event happened would this ecosystem survive?
Likely not- less biodiversity means ecosystem not as strong
Entire ecosystem could fall apart
Could effect neighboring ecosystems as well
Our food web is beginning to look more like a food chain & could easily break! X X X

10. Keystone species definition:
Keystone species= a species on which other species in an ecosystem largely depend on
if removed from the ecosystem, the ecosystem would change dramatically and lose biodiversity
Without the keystone, a brick bridge is weak & may collapse
Just like in ecosystem!

11. Wolf Case Study https://www.youtube.com/watch?v=ysa5OBhXz-Q
Write the following questions onto your notes (LEAVE SPACE BETWEEN EACH for RESPONSE) & answer these from the video:
What is a trophic cascade?
What National park did this take place in?
When were wolves reintroduced in the park?
What happened when the elk moved out of the valley and gorges?
What do beavers do for the ecosystem?
What happened when the wolves killed coyotes?
How did the wolves change the behavior of the rivers?

13. Wolf Case Study https://www.youtube.com/watch?v=ysa5OBhXz-Q
What is a trophic cascade?
When you remove a top predator or a key organism (i.e. a keystone species) and the rest of ecosystem is effected

14. Wolf Case Study https://www.youtube.com/watch?v=ysa5OBhXz-Q
2) What National park did this take place in? YELLOWSTONE

15. Wolf Case Study https://www.youtube.com/watch?v=ysa5OBhXz-Q
What is a trophic cascade?
What National park did this take place in?
When were wolves reintroduced in the park?
1995

16. Wolf Case Study https://www.youtube.com/watch?v=ysa5OBhXz-Q
4) What happened when the elk moved out of the valley and gorges? Trees & shrubs could grow around the rivers again. This stabilized the river banks & changed the path of the river.

17. Wolf Case Study https://www.youtube.com/watch?v=ysa5OBhXz-Q
5) What do beavers do for the ecosystem? They created their own aquatic niches- more life in ecosystem! They build dams to slow water flow and allow for more aquatic life

18. Wolf Case Study https://www.youtube.com/watch?v=ysa5OBhXz-Q
6)What happened when the wolves killed coyotes? More mice and rabbits More hawks! More weasels More foxes More badgers More ravens, eagles, and bears

19. Wolf Case Study https://www.youtube.com/watch?v=ysa5OBhXz-Q
7) How did the wolves change the behavior of the rivers? Wolves ate deer/elk so elk not near river as often More vegetation/trees More vegetation means stronger riverbed Stronger riverbanks = rivers stronger in areas

21. Summary: write at bottom of notes
7 sentence summary of notes