Ecology seeks to explain the distribution and abundance of organisms on earth

1. Ecology seeks to explain the distribution and abundance of organisms on earth • Autecology (physiological ecology) • Population ecology • Community ecology • Landscape ecology • Ecosystems ecology

2. Ecology seeks to explain the distribution and abundance of organisms on earth • Autecology (physiological ecology) • Population ecology • Community ecology • Landscape ecology • Ecosystems ecology

3. Ecology seeks to explain the distribution and abundance of organisms on earth • Autecology (physiological ecology) • Population ecology • Community ecology • Landscape ecology • Ecosystems ecology

4. The scientific process • Identification of patterns • Development of explanations or hypotheses for these patterns • Development of predictions from the hypotheses • Testing of predictions with data

5. Identification of patterns • Temperate edges tend to have more bird species that forest interior • Tropical edges tend to have fewer bird species than forest interior

6. Development of explanations or hypotheses for these patterns

7. Development of predictions from the hypotheses

8. Testing of predictions with data

9. Issues with study • Not many studies, particularly in tropical regions • Investigators used a variety of distance classes and techniques to assess edge responses

10. Ecology seeks to explain the distribution and abundance of organisms on earth • Autecology (physiological ecology) • Population ecology • Community ecology • Landscape ecology • Ecosystems ecology

11. Levels of organization in ecology • Individual • Population • Metapopulation • Species • Assemblage • Community • Ecosystem

12. Geographic range (distribution)—geographic area permanently occupied by a plant or animal taxon. • A geographic range is not equivalent to a home range or a territory of an individual.

13. Ecological biogeography • Organisms’ distributions are affected by their interactions with both their physical and biological environments

14. Physical environment and effects on distributions—the example of temperature regulation • Endotherms vs. ectotherms or homeotherms vs. poikilotherms

15. Implications of endothermy in birds and mammals • Ability to inhabit a wide range of environments • Higher food and oxygen demands • Limits to lower body size

16. Other examples of physical environment influencing distributions • Loblolly pine • Sugar maples • Starlings and Crested Mynahs

17. Comparative data

18. Cross-fostering experiment

19. Heater experiment

20. Biotic environment and effects on distributions

21. Competition, predation, mutualism and herbivory are other biotic interactions that may affect organisms’ distributions and abundances

22. Competition may at times control ranges, as in the example of the doves on islands off New Guinea, although this is difficult to say definitively.

23. Predators do not generally limit the geographic ranges of their prey, except in the case of exotic species

24. Species with tight mutualistic relationships with other species may be confined to a specific geographic range because of the relationship—for example Acacia plants and their ant mutualists of the genus Pseudomyrmex.

25. Most parasite species can live on only one host species, for example many lice live on only one species of birds. Hence, the geographic range of the parasite is strictly controlled by that of the host.

26. Ways in which humans (a biotic factor) influence the distribution and abundance of disease parasites • High human density necessary for measles to survive • Humans influence the density of host organisms besides themselves--White-tailed deer, bacteria, ticks and Lyme’s disease • Humans spread parasites from one continent to another • Humans change the landscape

27. Ways in which humans (a biotic factor) influence the distribution and abundance of disease parasites • High human density necessary for measles to survive • Humans influence the density of host organisms besides themselves--White-tailed deer, bacteria, ticks and Lyme’s disease • Humans spread parasites from one continent to another • Humans change the landscape

28. Ways in which humans (a biotic factor) influence the distribution and abundance of disease parasites • High human density necessary for measles to survive • Humans influence the density of host organisms besides themselves--White-tailed deer, bacteria, ticks and Lyme’s disease • Humans spread parasites from one continent to another • Humans change the landscape

29. Before European contact, the indigenous population of South America was between 4 and 10 million. • 100 years after contact, the population was approximately 100,000.

30. In many cases both physical and biotic environments of organisms will influence their distributions • Ex. Barnacles, Balanus balanoides and Chthamalus stellatus, on the Scottish coast

32. Biogeographers consider how physical and biotic factors shape geographic ranges within a historical perspective • Coffee example • New Zealand birds

33. Biogeographers consider these concepts and data within a historical perspective • Coffee example • New Zealand birds