1. Factors That Limit Distributions I: Biotic
Chapter 5
Factors That Limit Distributions I: Biotic

2. Dispersal can be tested by transplant exp.
Chapter Opener
Dispersal can be tested by transplant exp.
The presence of other organisms- predators, parasites, pathogens, or
competitors-may limit the geographical distribution of many species.
Some organisms produce allelochemicals
Allelopathy
Barriers
Biogeography: study of the geographical distribution of life
Fitness: particular genotype or phenotype to leave descendant in
future generation
Gene flow: The movement of alleles in space and time

3. Dispersal , transport of organism Biogeographers seek to understand
Chapter Opener
kingfisher
Dispersal , transport of organism
Biogeographers seek to understand
the historical changes in distributions
Not all dispersing individuals survive
to breed, so gene flow is restricted.
If colonization is successful,
dispersal will result in gene flow.

4. Dispersal limitation on Geographical distribution
Chapter 5
Dispersal limitation on Geographical distribution
Colonization and Extinction
Evolution of habitat preference
1)Limitation by predator
2)Disease and parasitism
3) AlleIopathy
4) competition

5. Zebra mussel- Caspian sea (ballast water in 1985)
Chapter Opener
Zebra mussel- Caspian sea (ballast water in 1985)
750,000/ m2

7. Zebra mussel 750,000/m2 Filter feeder: Lake Erie: clear
Figure 5-1
Zebra mussel
750,000/m2
Filter feeder:
Lake Erie: clear
In Hudson River
80-90 % phytoplankton
biomass reduced.

8. Hunting for fur trade by 1900 1914-small group in Pt. Sur
Figure 5-2
California Sea otters
Hunting for fur trade by 1900
1914-small group in Pt. Sur
Exploited species recolonize
3.1 km/ year between 1938 and 1972

9. 뉴트리아 (Myocastor coypus)
- 외래종

12. 연구 결과 (2014):수달
중앙값이라는 것은 median 을 의미하는 것이가? 평균도 같이 보여주지 그러냐? 그리고 이게 고도의 값이냐? 좀 이해가 안되는데?
N = 195

13. Original habitat: central and South America
Figure 5-3
Cane Toad
purse
Original habitat: central and
South America
1935-Queensland, female: eggs, twice a year

14. Figure 5-3
Scrab beetle
sugarcane

15. Female lay 8000-35,000 eggs at least twice a year
Figure 5-3
Female lay ,000 eggs at least twice a year
Toxic to many predators, some snakes are resistant.
Marked toad : 1.8 km per night
Moving west 40 km per year

16. Three modes of dispersal
Figure 5-4
Three modes of dispersal
Diffusion: gradual movement of a population across hospitable terrain
Ex) cane toad, California sea otter
2. Jump dispersal: movement of a population across unsuitable terrain
Ex) African honey bee
3) Secular dispersal: diffusion occur in evolutionary time
important in biogeography, NOT in ecological time

17. Dogwood: Mean seed dispersal distance was 6.7 m
Figure 5-4
Near parent
Dogwood: Mean seed dispersal distance was 6.7 m

18. tens rule : one in ten imported introduced, one in ten established,
Table 5-1
birds: % successful,
tens rule : one in ten imported introduced, one in ten established,
one in ten pest

19. Tens rule not apply: vertebrates between Europe and N. America-
Unnumbered Table 5-1
Tens rule not apply: vertebrates between Europe and N. America-
success at each step 50 % not 10 %.
Aquatic species in Europe: 63 %of introductions become established
Tens rule: % non native plants in N America-established

20. 135 million years ago : Gondwana
Figure 5-5
135 million years ago : Gondwana
Seed: heavy, not jump dispersal
Northofagus is a good example of how
present distribution is set
by geological event.
Continental drift

21. Nest site selection in birds: Example of directional selection
Figure 5-6
Nest site selection in birds: Example of directional selection

22. Habitat selection: Example
Figure 5-7
Habitat selection: Example 52 81
Breeding success of blue-winged teal: more successful if they nest in
areas that have more vegetation and farther away from habitat edge

23. Overcrowding reduce suitability
Figure 5-8
If individuals choose their habitat as in this model, fitness of individuals
will be equal in all three habitats at high density
Habitat A: good, C: bad
Overcrowding reduce suitability

24. Limitation by predators: Crabs and starfish
Figure 5-9
Limitation by predators: Crabs and starfish
Open coast:
wave, predators not important
(predator: 3 species crab and 1starfish)
Smaller species of crabs
could not kill large Mytilus

25. introduced Red fox control exp.
Figure 5-10
Changes in rock wallaby
: direct predation and reduce
the area
introduced Red fox control exp.

26. Something else must limit butterfly (Britain) distributions
Figure 5-11
Something else must limit butterfly (Britain) distributions

27. Native birds in Hawaii -mosquito
Figure 5-12
Extinction of native Hawaian bird- before 1900
Forest clearing and early 1900
Native birds in Hawaii -mosquito
Narive birds are much
more susceptible to
malaria than the
introduced species

28. Something produced by the grass and carried by the water
Figure 5-13
Allelopathy , apple tree seedling
Something produced by the grass and carried by the water

29. Root growth of ryegrass (with wheat) Common weed
Figure 5-14
Root growth of ryegrass (with wheat)
Common weed
ryegrass

30. Competion
Resource competition: occur when a number of organism utilize common resources that ar in short supply
Interference competition: when the organisms seeking a resource harm anther in the process
--competition : removal experiment
Competition between two species: interspecific com.

31. Euraisan otter vs American Mink
Mink-1900 introduced
Otter-native
From mink decline
Ecologist released 17 otters into an area occupied by mink
two years after this introduction…….

32. Two year after the release of otter in UK
Figure 5-15
Mink
Competition for space
Otters win
Otters
Two year after the release of otter in UK

33. Crossbill species and conifer cone