Materials

• 4 glass jars with lids (or other see through containers with lids)
• Tape
• Three different food items (one with preservatives, two without preservatives) that do not contain meat or fish
• Water
• Spray bottle
• Plastic six pack rings, cut up into small pieces

Top

Procedure

1. Ask students to work in teams of four.
2. Give each four glass jars, four lids, one piece of each of the three different food items, a few small plastic six pack ring pieces and access to tape and water.
3. Ask each team to take a food item, spray it with water, place the food item in the jar, place the lid securely on the jar, and then seal the lid to the jar with tape.
4. Spray plastic pieces with water, place them in the jar, and seal the lid to the jar with tape.
5. Place jars in a secure location to reduce the possibility of breakage, but in a location where students can readily observe the contents of each jar.
6. Over the course of two weeks, ask students to observe what is happening in each jar and to record their observations. Students should record how the color of the object changes, how the shape of the object changes, how the amount of moisture in the jar changes and what if anything appears that is new, either on the object or in the jar.
7. At the end of two weeks, students will make their final observations and then discuss what they observed. Students should consider these questions: Which items decomposed the quickest? Which items decomposed the slowest? Why do they think some items decomposed faster than others? Which items might benefit a wildlife community if they were left to decompose in its environment? Which items might be harmful to a wildlife community? How do decomposers help the other organisms in a community?
8. At the end of two weeks, throw the jars containing food items away. Do not open them. Some types of mold can be harmful for some people to breathe. The jar containing the plastic pieces, and the plastic pieces themselves, can be recycled.

Top

Experiment variations
For advanced students or students in the fifth grade, investigate how temperature impacts the experiment detailed above. Place the four jars in full sunlight, and four jars in the refrigerator. Record observations over time and compare results. If you were a fungus fearing scientist, would you want to study animals in the tropics or at the North Pole?

For advanced students or students in the fifth grade, investigate how water impacts the experiment detailed above. Spray food items with water and seal in jars and compare to food items that are not sprayed with water and sealed in jars. If you were an Athlete's foot fungus fearing athlete, would you rather run regular marathons during the summer in the Sonoran Desert or in the Congaree Swamp?

Top

Follow-up questions

• Why do you think people living in the 1800s and early 1900s salted and dried their meats?
• How does fungus suddenly appear on the week old loaf of bread in the kitchen? Where does it come from?
• What would happen if there were no decomposers and nothing ever decomposed?