1. Disturbance and Succession

3. Henry C. Cowles (center) about 1920

4. Successional Species Types Early successional, pioneer, opportunist Late successional seed dispersal distance long, goodshort, poor growth ratefastslow reach maturityearlylate number of offspring highlow competitive abilitylowhigh

6. The Kabetogama Peninsula

7. Kabetogama Peninsula

8. Beaver – Castor Canadensis

9. Beaver Dam

10. Pond and Bog Succession

11. Climax Community

13. Many Communities Experience Constant Disturbance or Change

14. Fir Wave on Mt. Coe, Baxter State Park, Maine

15. Fir Wave Up Close

16. Global Patterns of Species Richness Global Amphibian Diversity

17. Measures of Biodiversity Species richness – the number of species in an area – the simplest measure of biodiversity Species evenness or equitability – the relative proportion of number of individuals of each species in an area Often richness and evenness are combined into a Species Diversity Index

18. A comparison of species diversity in two communities Community 1 A: 25%B: 25%C: 25%D: 25% Community 2 A: 80%B: 5%C: 5%D: 10% D C B A

22. Animated Life of A.R. Wallace http://www.nytimes.com/video/opinion/100 000002534565/the-animated-life-of-a-r- wallace.htmlhttp://www.nytimes.com/video/opinion/100 000002534565/the-animated-life-of-a-r- wallace.html

23. Explanations for Global Patterns of Species Richness 1) Morphological diversity, spatial heterogeneity 2) High average rarity - no monocultures – in tropics 3) Climatic constancy of tropics 4) Geological age 5) Special adaptations in extreme (harsh) environments 6) Competitive "balance" 7) Alternating competitive advantages 8) "All niches filled theory" - saturation of community 9) Productivity from A.R. Wallace - 1878

24. Richness and Productivity

25. Richness and Structural Diversity

26. Environmental harshness

27. Richness and Climatic Variability

28. South American Rain Forest – Today and Past Refuges Richness and Environmental Age

29. Richness and High Average Rarity Global Plant Richness Local Centers Of Diversity Quality of Data

30. Richness and High Average Rarity Endemic Plant Species Globally

31. Richness and High Average Rarity Endemic Plants in Africa