Biology Department Activity

Materials:

• Crayons (green, red, brown)
• Pencils
• paper plates
• sticky labels
• *Handout of tree parts
• Picture of real tree rings or actual tree sample (suggested)

*Available in hard copy Mudd 71 or at link above

Concepts Used:

• Identify and explain the significance of a tree's annual rings
• Recognize and define the important parts of a tree
• Create a model of their own "life as a tree," and explain it to their classmates

Skills Emphasized:

• Plant Biology
• Creativity
• Verbal explanation

Background:

This activity introduces students to three parts of a tree and how they function. Does anyone know the purpose of the bark on a tree? Does anyone know what the words cambium (helps tree make new bark) and heartwood (center, support) mean? Has anyone ever seen the "rings" inside of a tree? Does anyone know what a tree's "rings" represent? Today we will learn the meaning and importance of these parts of a tree.

Description of activity:

* Estimated prep time (before student arrival): 25min

* Estimated activity time: 20-40 min depending on complexity and number of students.

1) Ask students if they know what the bark of a tree is for. After giving them a chance to answer, explain that the bark protects the tree (like our skin).

2) Explain to the students that there is something called cambium that helps tree make new bark.

3) Explain that the heartwood supports tree on the inside.

4) Show a cross section of a tree that shows the tree rings and the bark clearly.

5) Ask for any questions.

6) Explain that one significance of tree rings (the lines in the heartwood) is that it records how old the tree is. Explain that every year a tree grows a little more and a new ring is made. So, the small rings are from when the tree was smaller, and the bigger rings are from when the tree was older and bigger.

7) Show the students how to count a tree's rings in order to calculate its age. (Count only the dark or light shades not all of the shades). How old is the tree on the handout? (17yrs)

8) Give each student a paper plate, and brown, red, and green crayons.

9) Instruct the students to color the bumpy outside part of the plate brown, just like the bark on a tree.

10) Draw a green circle around the plate to represent the cambium, and draw a red heart symbol in the center of the plate to represent the heartwood.

11) Ask and answer any questions to check for comprehension.

12) Tell each child to put the same number of rings as their age on the plate.

13) Give each child a pencil and 2 sticky labels.

14) Place the label beside at least two important events in their life (birth, when started school, learned how to ride a bike etc).

15) Share their life as a tree with their classmates.

Review and Questions:

Different parts of a tree have different functions. A tree needs all of these parts to work. It is just like our own bodies (we have skin, blood, and bones like bark, cambium, and heartwood).

What did we learn today?

What are the three parts of a tree?

What do these parts do for a tree?

What do the rings inside of a tree tell us?

Additional Resources:

Lots of kid friendly information on all the different parts of a tree:

http://www.woodmagic.vt.edu/Kids/

Dendrochronology information: http://web.utk.edu/~grissino/

"The climate detectives" activity: http://www.epa.gov/globalwarming/kids/detectives.html

Alternatives for older/younger ages:

• For older kids you can discuss how bigger spaces between tree rings means that the tree grew more during that year, and ask why a tree would grow more in one year over another year (more rain/less rain, snow later, etc). Also, you could study the tree rings for evidence of disease, fire, etc.
• For really advanced students you could discuss how scientists use tree ring records to study climate change, called: dendrochronology.
• For younger kids you can spend time coloring the tree.

Ideas for plan came from:

http://www.lessonplanspage.com/ScienceSSMyLifeAsATree-RingsBarkCambiumHeartwoodK4.htm