Student Pages

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Teacher Pages

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Additional Resources

Additional Resources 

Option 1: Reinforce the activity by sending home copies of the family-friendly Web of Life Activity student page, which invites students to create individual models of a forest food web with their families.

Option 2: Invite students to use Webspiration or another online application to create a food web or food chain for the forest ecosystem, using information they gleaned from the activity. Their models should show the transfer of energy from one organism to another.

Option 3: With construction paper and colored markers, make cutouts of the food web organisms from the activity. Using a clothes hanger and thread to hang cutouts in the proper arrangement, students can construct a mobile that represents their food web. Challenge them to use arrows or other means to show the transfer of energy between the organisms.

Option 4: Challenge students to draw a food chain for their favorite food or meal. For information, you may first read aloud Who Eats What? Food Chains and Food Webs by Patricia Lauber, described in the Additional Resources.

Option 5: Have students compose their own poems about food webs, using as inspiration What’s for Dinner? Quirky, Squirmy Poems from the Animal World by Katherine B. Hauth and David Clark (described in Additional Resources) or another poetry book. Create a “Poet-Tree” using a dead tree limb—held in a can with rocks or plaster of Paris—onto which you clip each student’s poem.

Option 6: Read Pond Circle by Betsy Franco and Stefano Vitale, described in Additional Resources. Invite students to make a model of the pond food chain using paper chain links they glue together. On each link, have the students write one component of the food chain.

See Additional Resources for more ideas to enrich this activity.

Option 1: Assess students’ understanding of key terms used in this activity with the Key Vocabulary: Web of Life student page. Refer to the Key Vocabulary: Web of Life teacher page for the correct responses.

Option 2: Give students a copy of the Design a Food Web student page and ask them to answer the questions provided. You may use the Web of Life Evaluation Rubric teacher page to assess their work.

Option 3: Challenge students to create a mobile that shows the food web connections between different forest organisms.

Engage

1. Ask students what they need in order to be healthy. Ask: What do you think a tree or forest needs to be healthy? Direct them to work in pairs or teams to brainstorm all the components they think would be necessary for a healthy forest. Invite them to share their ideas with the rest of the class.

Explore

2. Have each student select a forest organism to study. (See Getting Ready in the Overview for possibilities.) Make sure the students select a variety of plants and animals, including mammals, insects, birds, reptiles, trees, and other plants.

3. Give students copies of the Food Web Research student page to help guide their research, making sure they understand what they need to find out about their organism. In addition to the information, students will also need to find or draw a picture of their organism. See Web of Life – Additional Resources in the Tools tab for suggested websites to begin their research.

4. After students have completed their research, have them make a nametag for their forest plant or animal on an index card, including its name and picture.

Explain

5. Have students sit on the floor in a circle, placing their nametags in front of them. Remind students of the food web concept (see Background). Ask students how they could model this process in an ecosystem using their nametags and string.

6. Starting with one “plant,” ask that student to hold the end of a ball of string and to name another organism in the circle that eats the plant. Pass the ball to this second student. Ask the second student to name another organism that eats or is eaten by his or her organism. This process will continue until each “organism” is linked to the ecosystem, and the ball is returned to the first student. Point out that the web shows all the ways that energy is transferred between organisms in an ecosystem. Discuss students’ observations, such as: What do you notice about your organism and all the other organisms? How are the organisms in an ecosystem connected to each other?

7. Have students slide back until the string is taut. Explain that students should keep still, but if they feel a tug, they should tug in response. When everyone is still, tell the student holding the original end of the string to gently begin tugging. Keep reminding everyone that if they feel a tug, they should tug in response. Through this mechanism, vibration will spread through the food web until everyone is tugging and the whole web is shaking.

8. Randomly select one of the organisms to drop out of the web, drawing the name from a hat or using another method. Ask if any other organisms should drop out because they eat or are eaten by that organism. After one or more have dropped out, randomly choose another organism and repeat the procedure. Continue playing for a few more rounds; then ask the following questions:
   • What happens when we remove a plant or animal from the forest ecosystem? (Organisms that depend on it are affected. The web itself changes shape.)
   • Is the change more dramatic when there are more plants or animals or when there are fewer? (Fewer.)
   • What do you think would happen if we add people to the web?
   • What does this model tell us about what might happen in a real forest?
   • In what ways is this model like a real forest food web? In what ways is it different?

9. Ask students how the food web model might illustrate what happens when one of the links in an ecosystem is harmed through natural or human causes. (The rest of the ecosystem feels the effects.)

Elaborate

10. Have students select one of the plants or animals from the activity, and write a story about the food web on which it depends.

11. Help students create a mural showing the forest “web of life.” Have them draw hills, valleys, streams, and other features on sheets of cardboard or poster paper and then add photos or drawings of the organisms they studied in the activity. By placing a push pin next to each plant or animal, they can use yarn to connect organisms to other animals and plants that eat or are eaten by them.

You may think of a forest as just a collection of trees, but a forest actually has many different animals and plants that interact with and depend on each other. It is a complex living system, or ecosystem.

Food is one important way that forest plants and animals are connected with each other. Forest plants use sunlight to make food. Through a process called photosynthesis that takes place in their leaves, they convert the sun’s energy to food energy. The plants use this food energy to live and grow.

Animals are not able to make their own food energy and must rely on plants for food. Some animals, called herbivores, eat plants directly. Some animals, called carnivores, eat other animals that eat plants. And some organisms, called decomposers, eat dead plants and animals.

A  food chain describes the transfer of energy from one organism to another in an ecosystem. One simple food chain is grass being eaten by a rabbit and then the rabbit being eaten by an owl. We can show this food chain using an equation like this:

sun → grass → rabbit → owl

Notice that this food chain, like all food chains, starts with the sun. The arrows that follow show the food energy being passed from one organism to the next.

In reality, it is rare for an animal to eat only one type of food. A food web shows the many different foods the animals in an ecosystem eat. It gives a clearer picture of the ways food energy is passed through an ecosystem and shows how the plants and animals in an ecosystem are connected.

Food is just one way that plants and animals depend on each other. In addition, animals need plants for shelter and shade. And plants need animals to pollinate flowers, spread seeds, and eat insects.

Discussion Questions

1. What is a food chain?
2. Do all forest food chains include the sun? Why or why not?
3. How is a food web different from a food chain?

By conducting research and simulating a food web, students will take a close look at a forest ecosystem and discover ways that plants and animals are connected to each other. While this activity focuses on forests, you can also use it to study other ecosystems, such as oceans, deserts, marshes, or prairies, by substituting the appropriate information.

Learner Objectives

• Identify a food chain or food web that contains a particular forest organism.
• Create a model of the forest food web.
• Explore what happens to the food web if one of the components is no longer present.

Materials

• 200 feet of string or yarn
• Access to the Internet or resource materials about forest plants and animals
• Food Web Research student page
• Index cards
• Push pins
• Cardboard or poster board for mural

Time Considerations

• Getting Ready: 30–60 minutes
• Doing the Activity: two 50-minute periods
• Evaluate: 20 minutes

Getting Ready

• Select a variety of forest plants and animals that are members of a food web. You might want to choose species specific to your local area. See the chart below for some possibilities. (The ones labeled with a * may also be found in an urban forest.)
• Students will need access to the Internet or other informational materials for their research. If necessary, arrange time in the computer lab, library, or media center.
• Decide what material from the Background page to share with students. For example, you might use the suggested Discussion Questions to support a conversation on the topic, or present some of the information as part of Explain in Doing the Activity. See the Web of Life Food Web teacher page in Tools for a shareable copy of the food web.
• See Additional Resources to find other supports for teaching this activity.

Possible Forest Plants	Possible Forest Animals
azalea* clover* columbine cottonwood Douglas fir honeysuckle* lichen* maple tree* pine tree* poison ivy shelf fungus violet	bark beetle barred owl bat* bear beaver box turtle* butterfly* chipmunk* deer earthworm* field mouse* grasshopper* hawk moth* king snake lizard* mosquito* opossum* rabbit* raccoon* red fox red squirrel* skunk* snail* tick* tree frog woodpecker*

* may also be found in an urban forest

Key Vocabulary

You may use the Key Vocabulary: Web of Life student page to introduce students to the following vocabulary terms or to review or assess their mastery of these terms. Note that the definitions below are geared for students, while the definitions that “pop up” within the activity text online are geared for the teacher.

Term	Definition
Carnivore	An animal that eats other animals.
Decomposer	An organism that eats dead material and causes it to break down.
Ecosystem	A community of living things interacting with their environment.
Food chain	The order in which animals feed on plants and on other animals.
Food energy	Energy that organisms get from food in order to live and grow.
Food web	All of the connected food chains in an ecosystem.
Herbivore	An animal that eats plants.
Photosynthesis	The process by which green plants make food from sunlight, water, and carbon dioxide.

PLT Conceptual Framework

• 3.2 Plant and animal populations exhibit interrelated cycles of growth and decline.
• 3.4 Ecosystems possess measurable indicators of environmental health.

Standards

See Standards Connections in the Appendices for a list of standards addressed in this activity.