1. Ecology-population dynamics II
Regulation of Population

2. Reproductive potential

3. Enormous reproductive potential of organisms

4. Reproductive potential

5. Huge reproductive potential

6. Environmental resistance

7. Environmental resistance

8. Population regulating factors

9. Hurricane_Density dependent or not?

10. Hillfire_Density dependent or not?

11. Predation_density dependent?

12. Predator vs prey density depednent

13. Predator vs prey_Camouflage

14. Predator vs Prey

15. Prey_group_alarm call

16. Predator_Cheetah_speed

17. Predation_density dependent?

18. Predator vs prey

19. The Kaibab deer story

20. Competition Two major types: Intraspecific competition
2. Interspecific competition

21. Overcrowding -Overlapping niche

22. Barnacle_filter feeders

23. Barnacle_Evidence for competition?

24. Niche_fundamental vs realized

25. Classic studies of resource competition by Gause (1934, 1935)
Paramecium caudatum
Paramecium aurelia
Paramecium bursaria

26. Classic studies of resource competition by Gause (1934, 1935)
Gause found that interactions between Paramecium aurelia and P. caudatum always ended in competitive exclusion.

27. Competitive exclusion “experimental” evidence

28. Classic studies of resource competition by Gause (1934, 1935)
Gause found that interactions between Paramecium aurelia and P. caudatum always ended in competitive exclusion.
Within 14 days Paramecium aurelia WON!

29. Classic studies of resource competition by Gause (1934, 1935)
In contrast, Paramecium bursia and P. caudatum could coexist.
Paramecium bursaria
Paramecium caudatum

30. Classic studies of resource competition by Gause (1934, 1935)
WHY?
In contrast, Paramecium bursia and P. caudatum could coexist.
Paramecium bursaria
Paramecium caudatum

31. Classic studies of resource competition by Gause (1934, 1935)
Because they inhabited different regions of the flask and ate different food.
P. bursia fed on the bottom of the flask, and P. caudatum ate the bacteria in suspension.

32. Classic studies of resource competition by Gause (1934, 1935)
In contrast, both P. aurelia and
P. caudatum ate the bacteria in suspension.

33. Gause’s Principle (Law)
When the niches* of two species overlap, there will be competition; and, if the overlap is extreme, there will be competitive exclusion.
*Niche = the ranges of conditions and resources within which an organism or species persists.

34. Gause’s Principle (Law)
When the niches* of two species overlap, there will be competition; and, if the overlap is extreme, there will be competitive exclusion.
This is also called the Competitive Exclusion Principle

35. Competition (-/-) is central to both evolutionary theory and ecological theory:
Competition can be a powerful selection pressure _in the long run_i.e. evolutionary
Competition affects the structures of communities _in the short run_i.e. ecological

36. Resource competition can only occur when
the same resource are used_overlapping of niche.
If resources are in limiting supply.

37. Competition _evidence? Suggest an investgation to prove your hypothesis

38. Resource Partitoning
Resource Partitoning

39. Life span_varying with population density

40. Human pop growth_I

41. Human pop growth_II

44. Demographic transition