1. Today: Reminders on the Take-home Final Intro to Ecological Principles Thinking About Wolves…, Group Quiz 6 If you finish early, work with me or your colleagues on your final draft. Due Thursday!

2. Next: Thinking About Ecology What is “ecology”? What sorts of questions does ecology seek to answer?

3. Thinking About Ecology Ecology encompasses a wide-range of inquiries, including: Organismal Ecology Population Ecology Community Ecology Ecosystem Ecology Landscape Ecology The Biosphere!

4. Thinking About Ecology Ecology is not Environmental Science! (Although Environmental Science pulls heavily from Ecology!) “To keep every cog and wheel is the first precaution to intelligent tinkering.” - Aldo Leopold

5. Thinking About Ecology: Community Ecology Competing Principles in Community Ecology: The Rivet Model vs The Redundancy Model

6. Thinking About Ecology: Community Ecology How do we know? We need to understand a species’ ecological niche: the total use of biotic and abiotic resources in its environment.

7. Thinking About Ecology: Community Ecology A species’ ecological niche is often heavily influenced by competition (the competitive exclusion principle)

8. Thinking About Ecology: Community Ecology An organism’s role in a community can also be described by its trophic level.

9. Thinking About Ecology: Community Ecology The trophic relationships in a community can be visualized in a food web Are there any limits the length of a food web? If so, why??

10. A Typical Biomass Pyramid: Thinking About Ecology: Community Ecology

11. Energy Transfer in an Ecosystem: Thinking About Ecology: Community Ecology

13. Possible Limitations: 1. The Energetic Hypothesis 2. The Dynamic Stability Hypothesis

14. Thinking About Ecology: Community Ecology Key Players in Community Dynamics: 1. Dominant species (high abundance or biomass) 2. Keystone species (pivotal role in community) 3. Foundation species (alter the structure or dynamics of their environment; facilitators)

15. Thinking About Ecology: Community Ecology Other Useful Ideas: Biotic Potential and Environmental Resistance

16. Thinking About Ecology: Community Ecology Keystone species exert influence on a community’s structure by virtue of their ecological niches. How do we figure out who the keystone species are??

17. Analyzing the Impact of Keystone Specie s

18. Thinking About Ecology: Community Ecology Thinking About the Gray Wolf Reintroduction in Yellowstone