Remember what a COMMUNITY is? How about an ECOSYSTEM ?

1. Behavior between species: COMMUNITIES & SPECIES INTERACTIONS Remember what a COMMUNITY is? How about an ECOSYSTEM?

2. Some common types of species interactions Predation Herbivory Symbiosis Competition

3. Three types of SYMBIOSIS barnacles on whale tapeworm Parasitism cleanerwrasse Commensalism Mutualism

4. Plants, herbivores & predators form food chains and "food webs" are eaten by are eaten by PRODUCERS PRIMARY CONSUMERS SECONDARY CONSUMERS (often there are more consumers above secondary)

5. Example of an even longer food chain: PRIMARY CONSUMER SECONDARY CONSUMER TERTIARY CONSUMERS PRODUCERS

6. Takes a lot of producers to feed 1 consumer... why? The 10% rule of BIOMASS

7. Food webs can be complex concept of "ecological niche"

8. Because of COMPETITION each species has its own NICHE ECOLOGICAL NICHE = the way a species "makes its living"; the "job" it has What exactly does it eat? What eats it? What habitat does it need? (etc.) No two species that live in the same area can have exactly the same ecological niche

9. DOMINANT species The most abundant species On land: usually is whichever tree/grass can out-compete the others In marine ecosystems: sometimes is a filter-feeder (not a plant)

10. KEYSTONE species Some examples: Low abundance but has unusually big impact on the ecosystem Without it the whole ecosystem will often "collapse"

11. Example: marine tidepools MUSSELS SEA STARS

12. "Keystone Predators" module Three seaweeds (algae) that photosynthesize: Three SESSILE consumers: Three MOTILE consumers: Nori seaweed Mussel Whelk (kind of snail) Acorn Barnacle Chitons Black pine Starfish (Pisaster) Gooseneck Barnacle Coral weed

13. Info from first experiment (optional) MUSSELS can out-compete the 2 barnacles Mussel Acorn Barnacle Gooseneck Barnacle

14. Info from second experiment (optional) Mussel Starfish (Pisaster) Chitons Seaweeds Whelk (kind of snail) Barnacles

15. Starfish are the only predator that’s keeping the dominant mussels in check MUSSELS STARFISH are eaten by Mussels can out-compete all other sessile creatures But starfish eat mussels STARFISH ARE KEYSTONE SPECIES

16. KEYSTONE species Some examples: Low abundance but has unusually big impact on the ecosystem Without it the whole ecosystem will often "collapse"

17. Gray wolf: another “top predator” ELK GRAY WOLF

18. Example: Yellowstone After eradication of wolf, aspen and cottonwood trees started declining why?

19. Elk eat aspen & cottonwood saplings in winter(often GIRDLE them)

20. 1995 - Wolves reintroduced to Yellowstone Animals were wild Canada wolves (not zoo wolves) captured 1995-96

21. Started hunting elk again...

22. ...and moose

23. ...and bison

24. Ecological effects Expected: Elk down Cottonwood & aspen up Riparian areas up Unexpected: Elk behavior also changes COYOTE DOWN RED FOX up BEAVER up, PONDS up PRONGHORN way up

25. The ecosystem was more complicated than we thought...... and wolves have huge effects Wolf actually doesn’t eat coyote - just kills them because of COMPETITION