Web of Life — Enrich
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.
Web of Life — Evaluate
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.
Web of Life — Doing the Activity
Engage
- 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
- 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.
- 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.
- 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
- 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.
- 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?
- 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.
![A small group of eight students sits on the floor. These students are in the process of modeling a food web. Each student holds part of one long piece of string that is shared throughout the group based on the interactions that their choose animal would have in the wild. When students tug on the string the other student can feel the interconnections within the ecosystem they are modeling.](https://eunit.plt.org/wp-content/uploads/2015/08/Web-of-Life-1.jpg)
Students are learning about the interactions of different creatures in their modeled food web.
Photo credit: Rose Banzhaf
- 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?
- 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
- Have students select one of the plants or animals from the activity, and write a story about the food web on which it depends.
- 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.
Web of Life — Background
![Owl mid flight](https://eunit.plt.org/wp-content/uploads/2015/08/3-5_Activity-3-Web-of-Life_Owl-hunt.jpg)
Owl hunting for rabbit
©Shutterstock: Alfredo Maiquez.
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
![](https://eunit.plt.org/wp-content/uploads/sites/2/2018/01/3-5_a3_sfi_plt_weboflife_background-300x219.jpg)
One example of a simple food web that could be found in North America
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
- What is a food chain?
- Do all forest food chains include the sun? Why or why not?
- How is a food web different from a food chain?
Web of Life — Overview
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.
A Home for Many — Tools
Student Pages
Teacher Pages
Additional Resources
A Home for Many — Evaluate
Option 1: Assess students’ understanding of key terms used in this activity with the Key Vocabulary: A Home for Many student page. Refer to the Key Vocabulary: A Home for Many teacher page for the correct responses.
Option 2: Challenge students to write an article about the life of a tree based on what they have learned in the activity. Give them copies of The Life of a Tree student page to focus their writing. Use the A Home for Many Evaluation Rubric teacher page to assess their articles.
A Home for Many — Doing the Activity
Engage
- Ask your students: In what ways do animals and other living things depend on trees? What animals have you seen in, on, or under trees? What were the animals doing? (Their answers may include eating, making a nest, resting, and so on.)
- (Optional) Read passages from Good-Night, Owl! (Grades K–3), Ancient Ones (Grades 1–5), or any one of your favorite books about animals that live in trees. Discuss: How did each of the animals use the tree? What were they getting from the tree?
Explore
![Two female students look closely at the base of a tree. These students are looking for signs of other living things that may live in or around this tree. The students will use their checklist or bingo card for ideas of what they may see.](https://eunit.plt.org/wp-content/uploads/2015/08/A-Home-for-Many-3.jpg)
During their nature walk, students study the base of a tree, looking for signs of things living in and among the trees.
Photo credit: Cara Dote
- Lead students to an area with one or more trees.
- Invite students to describe what they see living on each tree’s trunk and branches. Provide copies of the Tree Observation Checklist or Tree Observation Bingo student page to focus and record their observations. Point out that the pictures on the student page are examples and that they might find signs that look different. Explain that they may use magnifiers to get a closer look and digital cameras or electronic tablets to take pictures of the tree, the plants and animals living on and around it, and the surrounding area. Students may also use binoculars to see high into the tree.
- Give students plenty of time to make their observations. Encourage them to think about what the different organisms get from the tree and how the tree might benefit from the organisms.
Explain
- Back in the classroom, lead a discussion about students’ findings. What plants and other animals seem to depend on trees? In what ways do trees help other plants and animals?
- Invite students to use presentation software to make a detailed report of how animals and other living things depend on trees, based on their findings. Their reports should include how the tree and the other plants and animals in the ecosystem function together to support each other. They may use their checklist as well as any photographs they took to help with their presentation. They should also construct a scaled picture graph or bar graph from their observation data showing the numbers of plants and animals they found.
- Lead a discussion about the presentations, asking: What plants and animals did you observe in and around your tree? How does your tree help these plants and animals live? How do these plants and animals help your tree?
- Have students share their presentations with the rest of the class or with a younger grade class.
Elaborate
- Following everyone’s presentations, have students draw a living tree and a decomposing log, and show plants and animals that may be interacting with them. Instruct them to include a Venn diagram showing which organisms interact with either the living tree or the log, and which interact with both.
A Home for Many — Background
A habitat is the place where a plant or animal gets all the things it needs to survive, including food, water, shelter, and space for having young. Some habitats are huge and others are tiny. For example, a lion’s habitat may be an enormous grassland, while an insect’s habitat may be a single plant.
Trees are important habitats for many plants and animals. For some organisms, a tree may be just part of their habitat, and for others, a tree may be their entire habitat. A squirrel may come to an oak tree for acorns to eat, as well as depending on other trees and plants for food and nesting. But a patch of moss on the oak tree gets everything it needs right on that tree.
Even standing dead trees (snags) provide habitat for a number of different species. Tree frogs and beetles live under a snag’s bark, while woodpeckers and other birds feed on the insects that live on snags. Chickadees nest in holes created by woodpeckers. Squirrels and deer mice store food in the holes.
Dead trees also contain small insects, bacteria, fungi (FUN-ji), and other organisms that eat the dead and decaying plant matter. These decomposers are very important for any ecosystem because they recycle nutrients from the tree so that other trees and plants can use them. Without decomposers, trees and other plants would not get essential nutrients, and dead matter and waste would pile up.
Discussion Questions
- What animals or plants use living trees as part or all of their habitat? Name at least three different ones.
- What kinds of organisms use snags as their habitat?
- What important role do decomposers play in ecosystems?
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