Instructions

• First, do your reading assignment.
• Next, go through Session 1 on the Internet making rough notes and questions you want answered.
• Then do the exercises making notes of questions you want answered.
• Discuss problems or questions with you instructor in person or by e-mail.
• Make a final draft of your notes for this session in your notebook.
• Send a copy of your notebook covering this session to the instructor if you wish or save it until the end of the course.

Reading

• Berryman, A. A. 1997. Chapter 1 in Principles of Population Dynamics.
• Ludwig, D., B. Walker and C. S. Holling. 1997. Sustainability, stability, and resilience. Conservation Ecology [ online]1(1): 7. This is a reference article and, hence, you will not be held responsible for the mathematics or the details of the article. However, those of you who read it in depth and follow the mathematics should end up with a good, rigorous appreciation for the concept of stability and associated ideas in ecology. The URL is: http://www.consecol.org/Journal/vol1/iss1/

Exercises

1. Play the "Game of Life" to illustrate how simple feedback rules can give rise to very complicated dynamic patterns. Click here for details about the "Game of Life". You can run the "Game of Life" with the Population Analysis System PAS program PG1. What did you learn from this exercise?
2. Deer feed on certain woody shrubs and in so doing can severely reduce their abundance. Shrubs and trees compete with each other for space, sunlight, nutrients and water. Therefore, the more trees the less shrubs and vice versa. Shrubs, of course, are good for deer, but so are trees for they provide protection. Draw the feedback structure of this system. How many feedback processes are there and are they negative or positive? Describe these feedback processes and explain how this system can be stabilized.
3. In 1 page or less summarize the paper by Ludwig et al.

Examples

Examples of the kind of questions that could appear on the next examination are:

1. What is an exogenous process?
2. What effect does exogenous forcing have on population dynamics?
3. What is an example of an exogenous forcing variable?
4. What effect does an exogenous random factor have on population dynamics?
5. Give an example of an exogenous random factor?
6. What is an endogenous process?
7. What is an example of an endogenous variable?
8. What is a feedback loop?
9. What is positive feedback?
10. What effect does positive feedback have on population dynamics?
11. What is negative feedback?
12. What effect does negative feedback have on population dynamics?
13. What is meant by stability?
14. What causes time delays in feedback structures?
15. How do time delays affect the stability of dynamic systems?
16. What is meant by instability?
17. What causes instability in dynamic systems?
18. What is a metastable system?
19. How do disturbances affect the dynamics of metastable systems?
20. What is the dimension of a dynamic system?
21. What is the order of a feedback loop?
22. What determines whether a feedback loop is positive or negative?
23. What is the "Game-of-Life?
24. What did you learn from the "Game-of-Life"?
25. What additional information did you obtain by reading Ludwig et al.?

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