A Close Encounter of the Tree Kind

Charles T. Buzek Spry School
2400 S. Marshall
Chicago IL 60153
(312) 354-1400


These activities are designed for a 6-8th grade setting.
Students will learn how to estimate the heighth of a tree.
Students will learn that bark can be a distinguishing characteristic of
Students will learn how to make a bark print.
Students will learn how to estimate the age of a tree.
Students will learn the respiration rates of trees.
Students will learn about turgor in the tree's internal transportation
system and how it is affected by the sun.

Materials Needed:

A sheet of carbon paper
A large piece of art or construction paper
A ruler
Plastic baggies
A meter stick
Sections of string at least six feet in length
Masking tape


This is an outdoor activity that will allow your students to gather
information in the same way that scientists do.
Select teams of students (three or four in each group).

First activity-Tree measurement Each group to select a tree. One member will position themself next to the tree. Another will take the ruler and step forward or backward until the ruler exactly fills the heighth of the tree. With this accomplished the student with the ruler will move the top of the ruler from a vertical to a horizontal position making sure that the base of the ruler still sights at the base of the tree. In this position the student will sight down the other end of the ruler and identify some object in the same line as the tree. Once identified, a member of the team will go to that spot, then pace out the distance from that point to the tree. This is the heighth of the tree reduced to a horizontal linear measurement. Second activity-Age estimation Scientists estimate that mature trees grow at a rate of an inch a year. Students can select mature trees, measure them around with a tape measure or string with a meter stick, and then compute the average age. This activity will allow your students to add another piece of information in their description of a tree. Third activity-Bark rubbing Each species of tree has a distinctive bark. Students will be able to use this information to identify trees during the winter when there are no leaves. It is useful for students to see that while trees conform to a general image they are in particular quite different. Student teams will tape large sheets to a tree and then, using the carbon paper, will rub over the bark creating an image which reproduces the texture of the tree bark. Fourth activity-Water loss Each group to fasten a baggie on an individual leaf and leave it there for an hour. Placement of the leaf should involve experimentation some should be in the shade, others in the sunlight. After an hour the baggies should be collected and the water collected should be poured into a graduated cylinder. Follow-up activity Students will collect leaves and twigs from the tree. With all of the information collected the teams can now make a display providing all the information that they have collected. Performance Assessment:

Students will have successfully mastered the activities in this exercise
if they can do the following:

Describe the process used in measuring a tree.
Describe the theory behind age estimation.
Describe a theory for water loss difference in leaves on the shady side as
opposed to the sunny side.
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