Focus:
Learn about the different parts of a tree and how they work together to help a tree grow.

Materials:
• A visible tree.
• A diagram of the different parts of the tree (you may want to make an overhead transparency of the diagram or copy it on chart paper so that it can be easily seen by the entire class.)

Procedure:
Let the kids know that for the next few minutes they are going to use their imagination for this activity. Ask them to imagine they have x-ray vision. Have them look at their hand and tell you what they see. Have them look at their desk and tell you what they see. Do this a few times with the kids looking at different things with their “x-ray” eyes.

Now have them look at the tree. Have them focus on the trunk. Have them explain what they “see”. Show them the diagram and mention that if their x-ray vision is working properly, they should be “seeing”:

1. Outer bark. - The outer bark helps protect the tree from outside elements such as disease and insects.

2. Inner bark or phloem. - The phloem is a thin layer that transports the food (carbohydrates) produced by the leaves to the rest of the tree. (If you were to cut a ring around the trunk, through the outer and inner bark, the tree would die because the food supply would be severed.)

3. Cambium. - The cambium is a very thin layer that is responsible for growing new cells for the tree. (It’s so thin that you need a microscope to actually see it.) The cambium is what makes the trunk, branches, and roots grow thicker.

4. Sapwood or new xylem. - The sapwood is responsible for transporting water and minerals from the roots to the leaves.

5. Heartwood or old xylem. - The heartwood makes up most of the tree. It is the core of the tree and is actually dead wood. This means that this part of the tree no longer transports any nutrients. The heartwood gives the tree most of its support.

Have the kids look at the tree again and ask them if they can “see” these different layers.

Tell the kids they are going to “build” a tree. Choose one child to be the heartwood. Have two or three other children circle around the “heartwood” to form the sapwood. Have a few more children circle around to be the cambium. Do this until the children have built a whole tree. Afterward, review the parts and their functions.

(This activity was adapted from Ranger Rick’s Nature Scope: Trees are Terrific! Volume 2, Number 1, 1985)