Ecosystems and Living Organisms

1. Chapter 4 Ecosystems and Living Organisms

2. Evolution Overproduction Variation Struggle for existence Differential reproductive success • Genetic changes in a population through time. • Occurs through natural selection

3. Evolution • Darwin’s Finches - • adaptations

4. Evolution • Kingdoms of Life

5. Biological Communities • Rotting Log Community

6. Biological Communities Rocks Lichens Mosses • Succession: • How Communities Change over Time • Primary succession – virgin areas

7. Biological Communities Grasses Shrubs • Succession: How Communities Change over Time • Primary succession – Rocks Lichens Mosses

8. Biological Communities Grasses Shrubs Trees • Succession: How Communities Change over Time • Primary succession – Rocks Lichens Mosses

9. Biological Communities • Secondary Succession – disturbed areas

10. Species Richness • Number of different species in a community

11. Species Richness Forest Grassland ECOTONE Where edge effect occurs Typically greater species richness

12. Interactions Among Organisms • Symbiosis – • one species living in or on another species • results from coevolution

13. Interactions Among Organisms With mycorrhizae Without mycorrhizae • Symbiosis – • Three types 1) Mutualism – both benefit

14. Interactions Among Organisms Epiphytes • Symbiosis – • Three types 2) Commensalism – one benefits, other not affected

15. Interactions Among Organisms Tracheal mites • Symbiosis – • Three types 3) Parasitism – one benefits, one harmed

16. Interactions Among Organisms • Predation – predators consuming prey • Most common method:Pursuit and Ambush

17. Interactions Among Organisms • Animals that consume plants = herbivores • Animals that consume animals = carnivores • (can be further subdivided based on prey type, such as an insectivore)

18. Interactions Among Organisms • Defenses against predators: • Plant defenses – • spines, thorns • leathery leaves • toxic chemicals

19. Interactions Among Organisms • toxic chemicals • Defenses against predators: • Animal defenses – • armor, spines

20. Interactions Among Organisms • Defenses against predators: • Animal defenses – • armor, spines • toxic chemicals • camouflage

21. Interactions Among Organisms • Competition – • individuals attempting to utilize common resources • Intraspecific competition • Interspecific competition

22. The Ecological Niche Green Anole Brown Anole • An organism’s adaptations, use of resources, lifestyle, and habitat. • Fundamental vs. Realized Niche • Example: Tale of Two Anoles

23. The Ecological Niche Fundamental Niche of Green Anole Fundamental Niche of Brown Anole • Fundamental vs. Realized Niche Overlap Brown anole out-competes green anole, therefore . . .

24. The Ecological Niche Realized Niche of Green Anole Realized Niche of Brown Anole • Fundamental vs. Realized Niche Overlap

25. The Ecological Niche • Limiting Resources

26. The Ecological Niche • Competitive Exclusion: one species = one niche

27. The Ecological Niche • Competitive Exclusion

28. The Ecological Niche • Competitive Exclusion

29. The Ecological Niche • Resource partitioning

30. Keystone Species • Single species that strongly influences an entire community. • Example: figs • - frugivores depend upon fruit • - usually avoid figs, but during certain times of the year, figs are only species bearing fruit • - if figs were eliminated, many frugivores would die out

31. Species Richness Ecosystem services Ecosystem • Species Richness and Ecosystem Services Purify air / water Forests,Grasslands Produce / maintain soil Absorb CO2 Wildlife habitat Freshwater systems Moderate water flow Mitigate flooding Dilute / remove pollutants Drinking water Recreation

32. Species Richness • Species Richness and Community Stability • Greater the richness = Greater the stability