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Archbold Project FIRST
February Workshop: How and Why Walk

"Faculty workshops in field
ecology at Archbold:
an opportunity to enrich the
teaching of ecology for your
undergraduate students"

Project First at Archbold Biological Station

How & Why Walk

Background and Rationale

Before students are just "sent off" into the field to "ask questions", it is critically important for them to have some working knowledge and understanding of the scrub ecosystem into which they venture. They will then be in the position to ask much more informed and exciting questions. How to achieve this without giving a traditional lecture or teacher guided tour? How do you stop one or two enthusiastic students dominating the questions on a field trip. How do you maintain participation? How do you convey information about the ecosystem, in an interesting manner, to stimulate student curiosity while they are still at the exploring stage? How do you prime students with enough basic information so they are then able to pose relevant and fascinating questions they would like to address in more detail themselves? How do you guide them into asking relevant questions.

Our idea is to use a technique we have termed the "How and Why" walk. The aim is to encourage students/ participants not to ask the typical "what is this" questions while on a field tour, but rather form groups and ask questions that delve into a deeper ecological understanding of the system. All questions, therefore, must start with the words "How" or "Why". Students not only learn first hand about natural areas they also develop skills in how to pose 'good' questions. Of course a thoughtfully worded "How" or "Why" question serves as a prompt to get the "What" part of the answer at the same time. The instructor is not allowed to instigate discussion himself or herself, or talk about the ecosystem - except in response to a student question.

The "Why" and "How" questions also prompt the instructor to weave in basic ecological concepts into the field tour - of course the answers will have to be serendipitous and depend on an instructor's area of expertise. Answers will vary enormously from field trip to field trip depending on the questions asked and the things that are seen - e.g. which flowers are in bloom. To add consistency across field trips the instructor has to prepare a slate of say 5 basic ecological concepts they wish to cover in the field trip. These will inevitably be covered in very different ways on different days depending on instructors, questions and observations, but should always be covered at least once on every trip. They represent the minimum concepts that are critical to cover. The concepts may be illustrated by very different phenomena, and will have to be woven into the answers given to the questions posed.

After the field trip the 3 x 5 cards can be used, by both student and instructor, to review or assess the degree to which the basic concepts were conveyed. Over many years with different instructors, these may serve as a useful database of interesting ways to explain different phenomena in the field. The purpose of the 'How & Why Walk' activity is to introduce students to ecological concepts utilizing an inquiry-based teaching approach. In addition, educators are able to convey important ecological concepts in introductory field exercises. Avoiding 'what' questions frees the educator from specific details and allows them to capitalize on their own knowledge and expertise. Over time, questions and answers will serve as a resource for future exploration or as information for interested visitors.

 

How & Why Walk

Questions at February Workshop at Archbold

This activity enabled Archbold facilitators to convey basic ecological concepts in a field tour of Florida scrub. Prior to the activity, Archbold staff planned to try and cover the following concepts, which are critical to this ecosystem, during the walk:

1) Adaptation; scrub plants have adapted to xeric, acidic, and nutrient-poor soils.

2) Succession; the scrub system is dependent on seral fire conditions.

3) Habitat selection; open spaces within the scrub matrix are critical for many species.

4) Biogeography; the relic system of the Lake Wales Ridge results in high endemism.

The questions asked by the participant groups, simulating a student group, were:

1. Why are there some depressed bare patches on the ground where leaves accumulate? Why is there a depression on the land surface here? (Pointing to small crater like area- need photo.)

  • Area was logged in late 1930s and 40's
  • Old saw mill on property
  • Explosives were used for many years afterwards to remove stumps after timber harvest
  • Serve as open areas and have been retained throughout ecosystem - possibly some ecosystem functions changed as a result of stump removal
  • Stress long-term human impacts can be detected even in apparently "pristine" ecosystems

2. Why are the pine trees clumped in some areas and not in others?

  • Subtle gradients in elevation (cm differences not meters)causes a natural mosaic of wet and dry conditions, depth to water table
  • Slash pines often occur in small depressions or areas with moister conditions
  • Patchiness of underlying soil moisture interacts with patterns of fire.
  • Fire is a defining process in scrub ecosystems causing succession and patchiness in landscape that can be explained by variability in fire regimes.
  • Differential intensity of fires (natural and prescribed) results in a mosaic

3. Why is some of the wood dead and some alive on the same plant? (Pointing to scrub oak with dead branches and new resprouts.)

  • This unit was last burned in 1996, explained prescribed burn program. The dead wood is that part of the plant that was burned in the fire. The vast proportion of the biomass of scrub plants (particularly scrub oaks) is underground. These plants are clonal and. spread vegetatively. Many are endemic to Lake Wales Ridge or scrub ecosystems. They have massive underground root systems and sent up shoots after the fire. Post-fire is an intense period of time within which plants compete for space.
  • The green, living part of the plant is regrowth.
  • Decomposition is slow.
  • This clonal pattern of growth results in a very stable ancient plant communities in this ancient ecosystem where change in vegetative patterns takes place over centuries.

4. How was the pattern of dead and living pine trees created? Why are there so many dead pines in the landscape next to living trees? Why are some trees dead and some alive? (pointing to snag in landscape)

  • Tree are killed either by fire or lightening
  • Lightning strikes - 70 to 80 times per year. Many isolated snags in system from lightning
  • Some dead trees are from fires started naturally by lightning or by prescribed burns. The pattern of tree mortality as a result of burns is a function of the intensity and season of the fire.
  • Snags and fallen trees create fuel for fire and often result in intense fire spots that become open space. This cycle creates open spaces critical for other scrub species.

6. How are plants able to grow in 'pure' sandy soil?

  • As for many other biological questions - researchers are not really sure even though lots of research is conducted in this nutrient limited environment.
  • One possible answer: plants from relationships with the fungi on the outside of the roots. Similarly algal soil crusts in the soil are able to fix nitrogen.
  • We do know that scrub species are adapted to very low nutrient levels.
  • One advantage of this limitation is that scrub ecosystems are less threatened by invasive plants, many of which rely on higher nutrient levels.

6. Why do plants have such small leaves? Why are plant leaves held upright on the stems? Why are oak tree leaves thick and leathery? Why are there no broad-leaved plants? (Pointing to Lyonia ferruginea.)

  • Scrub is an extremely water limited. Long, dry season. Arid, desert-like environment.
  • Plants have adapted to these xeric, dry conditions
  • Upright curled under leaves reduce evapotranspiration from the stomata on the undersurface of the leaf.
  • Other adaptations to conserve water include thick and hairy leaves.
  • Small leaves - discussion of surface area/volume ration and reducing boundary layer conditions in smaller leaves.

Other questions:

Why is the saw palmetto trunk on the ground and buried in the soil?

Why are the crowns of the pine trees shaped so differently?

Why do scrub lizards have blue sides?

Why are stems on Lyonia lucida red?

How & Why Walk
Workshop Activity Review

Cooperative learning groups reviewed their field notes and listed the concepts they thought were communicated during the exercise. Archbold facilitators summarized the information and revealed the concepts (adaptation, succession, habitat selection, and biogeography) they were trying to convey while answering questions in the field. Faculty members agreed that all the concepts were conveyed during the activity; however, they commented that concepts like succession and adaptation were emphasized more strongly than others. Clearly the facilitators did not manage to convey the concepts of biogeography or high levels of endemism adequately. The cross-tabulation below provides a useful faculty evaluation tool. Also provides a database for preparing student evaluations - know what the students have learned. Additional concepts like plant-animal interactions were introduced and may be incorporated into the next field tour.

Concept FIU Stetson Edison UF USF
Plant-insect interactions         X
Natural history and human influence X X X X X
Clonal world below     X X X
Importance of fire ecology in system X X X X X
Complex and interconnected patterns, mosaic in system X   X   X
Plant physiology ecology X X   X X
System interactions       X X
Unknowns in system     X    
Scrub life/ reproductive history X     X X

Participant comments on the use of cooperative learning groups during the activity. The advantage of using cooperative learning groups it that you can assign roles to members of the group. If students have a specific task then they focus on the exercise.

Explicitly assigned roles helps students get over hesitation (shyness) in groups. Forces all students to participate, each group member has something to do and gets involved.

This is a good technique for resistant students.

Participant comments on the 'How & Why Walk' activity.

Advantages:

It's a mechanism for faculty to capitalize on their own knowledge and expertise. Good activity for teaching assistants.
Relieves insecurities in new teaching assistants. Based on the types and levels of the questions you can use this activity to assess prior knowledge.

As an introductory exercise you can assess student's background.

Activity engages students and gets them interested.

Could be used for future explorations.

Use the knowledge to address large scale issues; for example, have students use this knowledge about the ecosystem to come up with a management plan for scrub.



Enables you to make connections to things being taught in the class. In class you can explore the degree to which they got the concepts. If concepts didn't come across then you can make the connection after the fact. Problems to avoid: Students have a short attention span. May want to spread questions throughout the exercise. Walk and talk about the ecosystem in between questions.

Don't assume the student's level of knowledge. If students can't understand or conceptualize the answer then they lose interest.

Be aware that in mixed classes there is a range of knowledge.
Because of the differences in level of knowledge, you may want to give just the basics in the field then come back to the classroom to explore the larger concepts, then formulate questions.

Suggested improvements:
Have each cooperative learning group take a photo which conveys the question (use digital camera). I've found that students really get into this. They treat it as a competition, first they come up with really good questions, then they work hard to capture the question. And we have a visual database for future questions or studies.


For advanced students with an environmental science background suggest you give them more time to discuss questions and possible answers. Allow them time to come up with several hypotheses then ask the entire class for explanations. Create a dialogue with the students and challenge them by asking them what they think.