Nature and Food

Liz Campbell, Seattle Central Community College

Summary

In this activity students read articles or excerpts of books to explore the topic of sustainability in terms of food webs, roles of plants, animals, fungi, and bacteria and their own food choices. Students continue their exploration of these kingdoms with a visit to a farmers' market and a grocery store to compare locally grown foods and grocery store selections. Short written reports, responses, and group discussions are used as assessment tools. An optional introductory reading assignment and laboratory exercise explores organisms found in local samples of compost and soil.

Learning Goals

Students will be able to:

  • Understand issues about sustainability related to soil organisms and microbes and the effect they have on the environment.
  • Find reliable sources of information about regionally grown food.
  • Know availability and diversity of food grown locally compared with what the student consumes regularly.
  • Apply the ecological concepts of energy and nutrients in food web to themselves.

Context for Use

Many students have limited knowledge about the sources of food they eat: where it grows, how it grows, and the energy costs involved including transportation to the market place. By incorporating these concepts with basic biology concepts of ecosystem and sustainability, students in 100-level biology courses can be introduced to both. This assignment fits in with units on ecology and ecosystems at anytime of year. Students learn the role of a diversity of organisms in the production of food, and they see what is available from local sources. The greatest diversity of locally grown foods is found in fall, late spring, and summer, but seeing what grows during cooler weather in the Puget Sound region and comparing it with what is available in a grocery store is a valuable experience also so these exercises can be used at any time of year. In addition to applications to biology courses, some assignments could also augment an introductory nutrition or environmental science course.

Description and Teaching Materials

Learning about food sources, farmers markets and availability of local foods produced by or derived from animals, plants, bacteria, and fungi kingdoms.

There are several possible components to this activity: reading current literature, taking field trips to farmers' market, and observing soil, each of which can stand alone. The reading assignments involve a short reading, a written response, and conclude with group discussions during class time. The local food project can be completed in two weeks. Short amounts of class time are needed to introduce the project and answer questions. Outside of class time students set up their groups, visit markets and work on their small-group report of their findings.

The goal of the field trip exercise is to learn about the source, seasonality and diversity of foods that are sold locally. The exercise compares what is grown and sold by local farmers with what is available in a local grocery store. At the farmers market, students are asked to identify four food items each of which consists of or is derived from one of the following groups: plant, animal, fungus, and bacterium and to find out where the item was grown. If the food is processed, e.g., a bacterium in cheese, students should note what kingdoms are represented and find out where the ingredients came from. They then go to a grocery store to find the similar items and determine their source. The choices at the farmers' market will vary tremendously depending on the time of year, a fact that may be surprising to many students. Students can think about sustainability in terms of energy output to get food to them. Students figure out the distance the food travels to get to the market and the grocery store, and the distance and mode of transport the student used to get food.

Field Trip Assignment

(In-class time: periodically 5-10 minutes to learn about the project, and begin getting into groups; check in with students occasionally to answer questions and hear about progress. Allow at least two weeks for students to complete the two trips and have meetings with group members to plan and then complete the report.)

The goal of the groups' visit to a farmers' market and grocery store is to find food from each of the following kingdoms: animals, plants, bacteria, and fungi. Each food choice must connect to one of those four kingdoms.

In class, students get themselves into groups of no more than four people. Each group prepares a report of their findings and individual students keep a personal journal of their experience which includes group meetings and individual effort. The journal is read only by the grader.

After visiting the market and the grocery store, the group will prepare a report of findings.

Report from each group could include:

For each farmers' market item, record:
Date of visit
Name of farmers' market
Name and location of farmer
Name of food item
Trophic level
Local growing season for this food
Distance student traveled to get to market
Distance food item traveled to get to market
Mode of travel for shopper
Anything else the group thinks would be interesting to know, e.g., a recipe or instructions for how to use the food item.

For each grocery item, determine:
Date of visit
Location and name of store
Distance student traveled to get to store
Name of food item
Trophic level
Origin of food item (look for sign on product or label on packing box, or ask an employee
Seasons this food is available
Estimate of distance the food traveled to arrive at grocery store

The journal could include:
Student's role in the project (What share of the group effort did this student do?)
Reflections of the experience at group meetings, at the market, and the store.
  • Answers to questions such as the following:
    • What foods in this assignment were items the student normally eats?
    • What are some foods the student eats regularly which probably travel
      • More than 300 miles?
      • From outside the U.S.?
    • Could student realistically eat only local food (from less than 300 miles away)?Explain answer. What food item would student miss, something not available within 300 miles, such as bananas.
    • Based on some aspect of this project, make one change in food habit. Reflect on that change.
    • Thinking in terms of how much carbon goes into the atmosphere just transporting food, what is one change the student could make that could realistically make the diet more sustainable?
    • What part of this exercise stood out the most?
    • What crop(s) has the student actually grown or seen growing?

Additional Options for This Project

Observe a local P-patch
Visit a local CSA farm. Several of them encourage visitors. http://www.localharvest.org/csa/.
Do a "service-learning" project at a community garden.
Have a guest speaker from a local farm.
Investigate food sources used by the campus food service.
Investigate the source of the ingredients in a particular meal or student's favorite dish.
Eat lower on the food chain for a day - see if it reduces energy consumption for food production.
Raise a seedling e.g., lettuce (grows quickly to edible size); corn, bean, squash (observe germination, early growth and development stages of different types of plants).

Optional Reading and Laboratory Exercise About Ecosystems and Sustainability

Reading
(10-15 minutes class discussion time)

This activity could incorporate one or more introductory short readings about ecosystems, sustainability, the role of microbes, and food choices suitable as the class is beginning to study food webs and trophic levels. Students read an article or chapter(s) of a book and write a response essay and then discuss their reading with classmates in small groups. Having discussions in small groups of 3-4 students facilitates participation by every student. If groups of students read different articles, it is useful to form groups that include readers of each article to share their topics. (If more than one reading is being discussed, double the discussion time.)

Laboratory Exercise

(Two hour lab to explore the soil, and 15 minutes 1-2 days later to look at growth on Petri plates and record results.)

Using dissection scopes, students investigate the organisms that are visible in samples of soil from gardens or compost piles. They draw the organisms in their samples and are asked to hypothesize what the role of each type of organism is. To discover if there are bacteria or fungi not visible with these scopes, students make a slurry from a little bit soil and sterile TSB(has nutrients which help bacteria and fungi to grow) solution and spread it on TSA plates. Allow one or two days for microbial growth to appear.

Teaching Notes and Tips

It may be easiest to have group members live relatively close to each other so that making the trip together is easier to coordinate. Otherwise students in a group may chose to each be responsible for one item and to go to the most convenient farmers' market and grocery near home to find answers.

Students' reflections show that this was new territory for many of them, and they acquired a new appreciation for local biodiversity, the sources and effort required to produce their food and the complexity of the ecosystem.

I have used the Dietrich article as an introduction to the importance of bacteria and fungi working in the soil and the vital connections between small organisms that are easily ignored by humans. The reading and the lab investigation work well together to illustrate the diversity of organisms and their importance in food webs.

Assessment

Each student's grade is based on the completeness of the group's data records, the student's level of participation, and thoughtfulness of individual journal reflections.

Assessment Suggestions if Using Additional Options

  1. Questions are assigned for the reading to check for content and understanding of terms used in the reading. To be completed before class discussion.
  2. A one plus page response essay which goes beyond summarizing the reading and shows that the student looks for connections with textbook concepts and personal experience.
  3. A discussion or short answer question is included on a written exam.

Assessment Suggestions if Using Lab Exercise

Each student prepares a lab report including:

  • Drawings of organisms they saw, hypotheses about their possible roles/trophic levels/types of feeding, and interaction with above-ground organisms.
  • Discussion about seasonal changes in the soil.
  • Description of growth on Petri plates.

References and Resources

Information about market locations, schedules, and seasonal availability can be found online at http://www.pugetsoundfresh.org.

Information for year round availability of food produced in U.S.A., Mexico and Chile. http://www.chrobinson.com/en/us/.

Information about what is available locally for each month http://www.Seasonalcornucopia.com.

Reading suggestions to explore ecosystems and sustainability:

Articles
Condor, Bob. Seattle Post-Intelligencer 5/28/07 section E1, "The Path to Sustainability Starts in Our Homes." Essay on U.S. consumers and what sustainability means to them.
http://seattlepi.nwsource.com/health/317302_condor28.html.

Dietrich, William. Seattle Times5/23/99 "Dirt - Life, Death, War and Romance."
Discusses roles and interactions of diverse soil-dwelling microbes with other species.
http://community.seattletimes.nwsource.com/archive/?date=19990523&slug=pdirt23.

Books
Beattie and Ehrlich. Wild Solutions. Chapter 1 introduces the importance to humans of diversity in plants, animal and microbes and their role in sustainability.

Michael Pollan. Omnivore's Dilemma. Introduction "Our national eating disorder". A discussion of nature, human's food chains, and American eating habits.

Evergreen State College