BIOL 4120: Principles of Ecology Lecture 8: The Distribution and Spatial Structure of Populations

1. BIOL 4120: Principles of Ecology Lecture 8: The Distribution and Spatial Structure of Populations Dafeng Hui Room: Harned Hall 320 Phone: 963-5777 Email: dhui@tnstate.edu

2. Dispersion The spacing of individuals within respect to one another within the geographic range of a population Not dispersal

3. Distribution patterns 1. Random: Equal chance of being anywhere. Neutral interactions. 2. Uniform (spaced) distribution of resources. Regular: Uniformly spaced. Exclusive use of areas. Antagonistic interaction individuals avoid one another. 3. Clumped: Unequal chance of being anywhere. Mutual attraction between individuals. Patchy resource distribution.

4. Competition for water: uniform distribution benefits allCompetition for water: uniform distribution benefits all

6. 10.4 The spatial structure of populations parallels environmental variation Population density Number of individuals per unit of area Variation in population density

7. Influenced by available habitat Carolina wren: Northwards -7oC; Westward>52mm When all environmental factors within its range of tolerance, the organism can live in its habitat Horned lark Avoids forests Available territory

8. Ideal free distribution Lincoln-Peterson index: N=nM/R Lincoln-Peterson index: N=nM/R

9. BIOL 4120: Principles of Ecology Lecture 8: The Distribution and Spatial Structure of Populations Dafeng Hui Room: Harned Hall 320 Phone: 963-5777 Email: dhui@tnstate.edu

10. Dispersal from high-density to low density patches Lincoln-Peterson index: N=nM/R Lincoln-Peterson index: N=nM/R

11. Even with dispersal, population distribution can not move to very poor habitat

12. 10.5 Three types of models describe the spatial structure of populations Metapopulation models a set of subpopulations occupying patches of a particular habitat type between which individuals move occasionally Source-sink models Add differences in quality of suitable habitat patches: source population and sink population Landscape models consider effects of differences in habitat quality within the habit maxtrix, thus influence the quality of a habitat patch (a nearby patch provide safe roosting sites, nesting materials, pollinators, or water) or negative impacts (predators). Habitat maxtrix also inflences movements.Metapopulation models a set of subpopulations occupying patches of a particular habitat type between which individuals move occasionally Source-sink models Add differences in quality of suitable habitat patches: source population and sink population Landscape models consider effects of differences in habitat quality within the habit maxtrix, thus influence the quality of a habitat patch (a nearby patch provide safe roosting sites, nesting materials, pollinators, or water) or negative impacts (predators). Habitat maxtrix also inflences movements.

13. 10.6 Dispersal is essential to the integration of populations

15. 8.7 Macroecology addresses patterns of range size and population density

20. Chinch bugs: pest, feed on grasses, and crops such as wheat, barley, oats, corns, etc.Chinch bugs: pest, feed on grasses, and crops such as wheat, barley, oats, corns, etc.

21. Invasive species Gypsy moth is native to Europe and Asia and was introduced to US by an French astronomer (Massachusetts) as a silk moth. In the forest of eastern US, the losses to Gysp moth in 1981 were $764 million. No predator, enough food Cost of invasive species in US every year: $123 billion. Ants Kudzu Gypsy moth is native to Europe and Asia and was introduced to US by an French astronomer (Massachusetts) as a silk moth. In the forest of eastern US, the losses to Gysp moth in 1981 were $764 million. No predator, enough food Cost of invasive species in US every year: $123 billion. Ants Kudzu

22. Invasive species Zebra mussel, Asia carp; fire ants.Zebra mussel, Asia carp; fire ants.

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