Ecology: The study of how organisms interact with each other and the environment.

1. Ecology: The study of how organisms interact with each other and the environment.

2. Ecology Definitions: • Habitat:The space or environment when an organism lives • Niche: role of an organism in a community • Biotic Factors: All the living things within an environment • Abiotic Factors: All the physical (non-living) things in an environment

3. Connections to the size of the acorn crop

4. Limiting Resources • Environmental factors that restrict the growth of populations.

5. Effect of competition on an organism’s realized niche

6. Competition • Two or more individuals attempting to use the same resource • Intraspecific competition • Among individuals within a population • Interspecific competition • Between different species

7. Interspecific competition

8. Competitive exclusion principle • Two species cannot occupy the same niche in the same community for an indefinite period • One species is excluded by another as a result of competition

9. Some species reduce competition by resource partitioning • Competition among species is reduced by character displacement • Structural ecological and behavioral characteristics diverge where ranges overlap

10. Resource partitioning

11. Predation • Consumption of one species (the prey) by another (the predator) Co-evolution • Predator and prey both evolve more efficient ways to interact

12. Ecological interactions among species

13. Defenses • Mechanical defenses • Associating in groups • Cryptic coloration • Warning coloration • Müllerian mimicry

14. Cryptic coloration

15. Symbiosis • Mutualism • Both partners benefit • Commensalism • One partner benefits and the other is unaffected • Parasitism • One partner benefits while the other is harmed

16. Mutualism between flowering plants & pollinators

17. Mutualism between clown fish & sea anemone

18. Commensalism: Spanish moss & trees

19. Parasitism: Ticks and Mammals

20. Parasitism

21. Keynote species • Present in small numbers but are crucial in determining the species composition and ecosystem functioning • Dominant species • Affect the community because they are so common

22. Species richness • Number of species within a community • Species diversity • Relative importance of each species within a community

23. Effect of community complexity on species richness

24. Ecological Succession • Primary succession • Occurs in an area not previously inhabited • Secondary succession • Occurs where there is a pre-existing community and well-formed soil

25. Ecological SuccessionPioneer Species= annual plants/grassesSecondary Species= shrubsClimax Species= trees

26. Intermediate disturbance hypothesis • Disturbance affects succession and species richness • Species richness is greatest at moderate levels of disturbance

27. Intermediate disturbance hypothesis

28. The nature of communities • Organismic model • Views a community as a superorganism that goes through stages of development (succession) • Individualistic model • Abiotic environmental factors are primary determinants of species composition • Organisms are independent