Cycles Research Project

STUDENTS WILL BE ABLE TO:
- Explain concept of cycles.
- Give examples of common cycles in local ecosystem.

GUIDING QUESTIONS:
What is a cycle?
How are cycles important in ecosystems?

MATERIALS:
- Cow costume
- Sun costume
- Plant costume
- Shopping bag labeled "SUGAR"
- One black balloon
- Three yellow balloons
- Safety pin
- Research materials (access to library, Internet)

CLASS ACTIVITIES:
Day 1: Wonder
The following play is taken from http://www.planetguide.net, which along with the associated book Dr. Art's Guide to Planet Earth by Art Sussman, Ph. D. is an excellent classroom resource for introducing and exploring the earth system.
1. Have three volunteers stand next to each other representing the sun, a plant and a cow. Explain to them and to the spectators that they will do the same scene three times. The first time you will show them their actions and say their words for them. The second time they will do their actions and say their lines. The third time they will do their actions silently, and the audience will say their lines.
2. Begin with the sun.

Sun's Words: I am the sun. I am the main source of energy for planet Earth.
Sun's Action: Give a yellow balloon to the plant.

3. Next say the plant's words and help it do its actions.

Plant's Words: I am a plant. I take energy from the sun and carbon dioxide from the air and I make sugar.
Plant's Action: Take the yellow balloon it got from the sun and a black balloon and put them inside the sugar shopping bag.

4. Next say the cow's words and help it do its actions.

Cow's Words: I am a cow. I eat the plant. I breathe the carbon dioxide back into the atmosphere. I use the energy in sugar to walk, eat, be warm, moo, mate, be a cow. All that energy eventually changes to heat and leaves the planet.
Cow's Action: Chew on the plant's arm. Take the black balloon out of the shopping bag and give it to the plant. Take the yellow balloon and, pointing into the distance, pop it with the safety pin.

5. After doing the scene three times, ask the audience how many black balloons were used. (One.) How many black balloons would be used if we did the scene ten more times? (Still just one.) Explain that this illustrates that Earth is a closed system for matter, summarized by the phrase matter cycles. The same atoms go round and round.
6. Ask the audience how many yellow balloons were used. (Three.) How many yellow balloons would be used if we did the scene ten more times? (Ten more.) Explain that this illustrates that Earth is an open system for energy, summarized by the phrase energy flows. Earth is a solar planet, receiving energy from the sun. That energy does not stay here; it leaves the Earth system as heat.
7. Review interactions by pointing out that the plant and cow depend on each other. Explain that their relationship helps illustrate that Earth is a networked system for life, summarized by the phrase life webs. Earth is unique in the solar system in featuring a global web of life.
8. Develop a working definition of the term cycle.
9. Brainstorm types of cycles in the ecosystem. Students should keep past lessons in mind - for instance, what cycles can they identify in the game Fox, Mice, and Seeds?
10. Partner students. Each pair will spend the next couple days researching a specific cycle. Suggested cycles include:

• Water
• Nitrogen
• Carbon
• Oxygen/Carbon Dioxide (gas exchange in organisms)
• Rock
• Minerals (Calcium, Phosphorous, etc.)
• Life cycles of local organisms: A range of taxa and living strategies should be represented. For instance, groups could research life cycles of endangered plants, invasive plants, insects, large mammals, etc.
• Predator/prey population cycles
• Seasons of the year (students should focus on mechanisms driving this change)
• Climatic cycles (for instance, El Niño or large-scale climatic changes causing ice ages)

Days 2-3: Explore and Identify
1. Students should carry out research project.

Day 4: Organize
1. Each group should prepare two products for presentation at the Round Table:

• A clear, understandable poster displaying the cycle.
• A kinesthetic means of acting out the cycle.

Day 5: Share
1. At the Round Table, have students present their cycles.
2. Discuss: Can any cycles be disrupted or changed? What happens then?
3. Ask your students to consider what is being cycled in life cycles - unlike other cycles that they studied, it is not the specific molecules or atoms that remain intact; instead, it is the genetic code. Are there other cycles that they studied where something other than matter was cycling?