NOTES TO FACULTY

The data here are quite straightforward and therefore can be easily used in a brief turn-to-your-neighbor exercise even in a large class.

This is a "neat" study in the sense that fir waves are intriguing and common in the northeast but were clearly a puzzle before Sprugel's study. The paper is written in the older, conversational style, and Sprugel clearly outlines the logic of his thinking and evidence he uses. You can therefore easily explain to students step by step the logical development of his ideas about wind and rime ice.

This is also a useful paper if you are presenting the historical development of ideas about succession and critiques of Clementsian "stable climax" concept. You can also use the minute paper question below to stimulate a discussion about the meaning of "stability" in ecology.

Discussion Questions:

• Imagine that you are walking around in the balsam fir forest in upstate New York that Sprugel studied. Describe the sizes of the trees (e.g. are they all the same size?).


• Sprugel did this study to challenge the notion that young forest communities develop over time into stable climax systems. He said: "For years, it was generally assumed that in the absence of disturbance the vegetation on any site would eventually reach a self-reproducing steady-state equilibrium, in which all system properties would be relatively constant through time." Explain Sprugel's statement and how the fir wave study addresses the issue of "stable climax systems".


• In addition to counting and measuring trees, Sprugel also measured prevailing wind directions and wind speed. Why was this so important to the study?


• Orians (1975) suggests that stability may mean many different things: the absence of change ('constancy'), the length of survival ('persistence'), resistance to perturbation ('inertia'), speed of return after perturbation ('elasticity'), the displacement from which return is possible ('amplitude'), the degree of oscillation ('cyclic stability'), and the tendency to move towards a similar end point ('trajectory stability'). What does "stability" mean in the context of Sprugel's study?

Orians, G. 1975. Diversity, stability and maturity in natural ecosystems. In W. H. Van Dobben & R. H. Lowe-McConnell, eds. Unifying Concepts in Ecology, Dr. W. Junk, The Hague.

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Student Assessment: Minute Paper

      This is a very useful way to get quick feedback at the end of a class. Many faculty have students write their "paper" on a 3x5 card that students drop in a box as they leave the class. After discussion of the study in class ask students to write a several sentence response to the following:

      Explain the logic of Sprugel's study - the step by step approach that he used to reach his conclusions.



EVALUATING AN ISSUE: How do you know whether it is working?

      On-going (also called formative) evaluation of the approaches your are using is critical to the success of student-active teaching. Why try out new ideas if you don't know whether or not they are working? This is a brief overview of formative evaluation. For more information, go to the Formative Evaluation essay in the Teaching Section.

Course Goals:

      Formative evaluation only works if you have clearly described your course goals - because the purpose of the evaluation is to assess whether a particular technique is helping students reach these goals. For instance, most of us have "learn important ecological concepts and information" as a course goal. If I reviewed the nitrogen cycle in a class, for evaluation I might ask students to sketch out a nitrogen cycle for a particular habitat or system. Each student could work alone in class. Alternatively, I might ask students to work in groups of 3 and give each group a different situation (e.g. a pond receiving nitrate from septic systems, an organic agricultural field, an agricultural field receiving synthetic fertilizer). The students could draw their flows on a large sheet of paper (or an overhead transparency) and present this to the rest of the class.

The Minute Paper:

      Minute papers are very useful evaluative tools. If done well they give you good feedback quickly. Minute papers are done at the end of a class. The students are asked to respond anonymously to a short question that you ask. They take a minute or so to write their response in a 3x5 card or a piece of paper. You collect these and learn from common themes. In the next class it is important that you refer to one or two of these points so that students recognize that their input matters to you. The UW - FLAG site (www.wcer.wisc.edu/nise/cl1/flag/) gives a good deal of information about using minute papers including their limitations, how to phrase your question, step-by-step instructions, modifications, and the theory and research behind their use.