1. Ecology 4 Notes Interactions between Species

2. Different ecosystems around the world… Although we haven’t discussed biomes in detail yet, which ones do you think are most “productive”? Although we haven’t discussed biomes in detail yet, which ones do you think are most “productive”? Which ones are “least productive”? Which ones are “least productive”?

3. Very productive ecosystems… Tropical rainforests Tropical rainforests Temperate evergreen and deciduous forests Temperate evergreen and deciduous forests Savanna is pretty good… Savanna is pretty good… THE MOST productive is actually the estuaries, swamps, and marshlands!!! THE MOST productive is actually the estuaries, swamps, and marshlands!!!

4. Why would these be more productive than tropical rainforests? It has to do with the availability and variety of niches …along with pretty ideal conditions for organism growth and prosperity… It has to do with the availability and variety of niches …along with pretty ideal conditions for organism growth and prosperity… More niches reduces competition More niches reduces competition

5. What is a NICHE? An organism’s role within the structure and function of an ecosystem An organism’s role within the structure and function of an ecosystem How does it get nourishment? How does it get nourishment? What is it’s habitat? What is it’s habitat? Is it part of a predator/prey relationship? Or some sort of symbiotic relationship? Is it part of a predator/prey relationship? Or some sort of symbiotic relationship? Who does this it compete with? Who does this it compete with? How does it interact with abiotic components of the environment? (tolerance) How does it interact with abiotic components of the environment? (tolerance)

6. NICHE NOT just the habitat NOT just the habitat Sum total of an organism’s use of its biotic and abiotic resources. Sum total of an organism’s use of its biotic and abiotic resources.

7. Competition Interactions within or between populations for a limited resource. The closer the niches, the more intense the competition. Intraspecific more intense than interspecific.

8. Gauses’ Competitive Exclusion Principle One species eliminates the other one entirely when two species niches overlap and the system is allowed to go to saturation (intense competition). Paramecium caudatum Paramecium aurelia (pg 78 text)

9. Paramecia – Kingdom Protista (ciliate)

11. How similar can two species niches be and still coexist? If two species have overlapping niches, it is to the advantage of both to REDUCE COMPETITION. If two species have overlapping niches, it is to the advantage of both to REDUCE COMPETITION. RESOURCE PARTITIONING RESOURCE PARTITIONING

12. Stable Coexistence MacArthur’s Warblers 5 North American Warblers appear to have the same niche. How do they coexist? Resource partitioning Differences in portions of trees where they feed, nest, timing of feeding, etc.

14. Types of Community Interaction Commensalism (+ o) Commensalism (+ o) Mutualism (+ +) Mutualism (+ +) Predation / Parasitism (+ -) Predation / Parasitism (+ -) Competition (- -) Competition (- -) Parasitism, commensalism and mutualism = all examples of symbiosis

15. Examples of Types of Community Interaction Deer and rabbits both feed on the grass in a meadow.

16. Competition!

17. Examples of Types of Community Interaction Remora fish use suction cup like structures to attach to sharks. They get a free ride to lunch… But they don’t hurt the sharks… Sometimes they eat parasites… They also eat small bits of food missed by the shark or other host.

18. Remora attached to a tiger shark Commensalism / Mutualism

19. Examples of Types of Community Interaction Protozoans live in and digest cellulose for termites. And they get a “free” place to live…

20. Trichonympha Mutualistic flagellated protozoan found in the gut of termites. They digest cellulose for the termite. Mutualistic flagellated protozoan found in the gut of termites. They digest cellulose for the termite.

21. Termites and Trichonympha = Mutualism

22. Examples of Types of Community Interaction Fish-cleaning shrimp set up stations to remove parasites from fish. The shrimp get food….

23. Shrimp that cleans fish Mutualism!!

24. Examples of Types of Community Interaction Egrets (birds) feed off of invertebrates that cattle kick up when they walk around the pasture.

25. Cattle Egrets in England Cattle Egrets in England Commensalism! Commensalism!

26. Examples of Types of Community Interaction Ants feed off of sugary secretion from Acacia tree and protect the tree from herbivores.

27. Ant sipping on sugar from Acacia Ant sipping on sugar from Acacia Mutualism! Mutualism!

28. A tick on a horse… As the tick is sucking the blood of the horse, it is benefiting while the horse is not… Parasitism!

29. LICHENS LICHENS Algae provide sugar and possibly nitrogen for the fungus. Algae provide sugar and possibly nitrogen for the fungus. The fungus helps to maintain water and minerals for the algae. The fungus helps to maintain water and minerals for the algae.

30. This is a really good example of… Mutualism!!!

31. Predation Not really a symbiotic relationship, but it is certainly an important interaction Permits energy flow from one trophic (feeding) level to another.

32. Predation Regulates the population growth of the next lower trophic level Lynx and Hare

33. Lynx

34. Hare in winter Hare in summer Hare in summer

36. Would this be positive or negative feedback? NEGATIVE!!!!

37. Prey Techniques Constant interaction between predator and prey populations selects for increased efficiency of both. Any characteristic that increases the predator’s efficiency at detecting, capturing or eating prey would be selected for. Conversely, any prey characteristics that would enhance its ability to avoid detection, capture or being eaten would also be selected for (an advantage)

38. It is an ARMS RACE! (coevolution)

39. Escape utilizing behavior. Starling and peregrine falcon. Starlings tighten flying formation when peregrines are nearby. Falcon has vision 5 times better than humans. Stoops, closes wings and dives at speeds greater than 200 miles per hour Prey killed instantly by the talons.

40. Peregrine Falcon

41. Starling

42. See Chapter 4 for more details… ( pg 73-74 for defenses; also see symbiotic relationship examples )