Visit Your Local PBS Station PBS Home PBS Home Programs A-Z TV Schedules Watch Video Donate Shop PBS Search PBS
Search NOVA Teachers

Back to Teachers Home

Methuselah Tree

Ideas from Teachers


(Gr. 9-12)
Objective
To use tree cookies to determine climate patterns where the tree had been growing.

Materials

  • copies of NOVA's "Methuselah Tree" student handout, Tree Ring Science
  • variety of tree cookie samples (cross sections of tree trunks), if possible from different locations such as woodlands, wetlands, etc.
  • rulers to measure ring width
  • pencils and paper to record observations and hypothesis

Procedure
Briefly explain the science behind dendochronology. Use the teacher's guide, as well as referring to some of the other resources provided, including the video. A discussion on cell growth would be beneficial, because the healthy growth of the cells within the tree is a major factor in the successful growth of the tree itself. Explain the factors that may inhibit the yearly growth of a tree (such as drought, cold winter, and volcanic activity).

After the discussion, provide students with the Tree Ring Science activity. Using the student handout provided, demonstrate the correct way to measure tree rings. The students should work in groups of at least two. Once the activity has been completed, hand out the tree cookie samples, rulers, and paper. (Samples can be obtained from various sources, including landscaping companies.) Students will observe and measure the tree rings. Also, they may make some drawn observations detailing the rings.

Students should now be able to determine the age of their tree samples. By measuring the width of the tree rings, students will then determine which years were the best growth years for their trees. In addition, they will also be able to point out any years where growth may have been hindered. A drought period could be determined by a succession of closely spaced rings, offering little growth measurement.

Students may notice slight differences in the size and pattern of the tree rings. Have students use this information to hypothesize what region their trees may have been growing (this works especially well if you have tree cookies from very dry or very wet climates).

You may also want to direct students to create a time line of their trees, with their hypothesis on what climate issues or changes each tree might have experienced.

Assessment
We have used the tree ring activity in an after-school program and the tree cookies in a demonstration. We are planning to use both in a nature workshop with high school students. In the workshop, we will explore the ability of plants to be endlessly adaptable and discuss seed and seed travel. We will also look at the roles of animals in nature, as well as the definition and composition of different ecosystems.

Classroom Tips
This activity can be used to discuss the impact humans have on the natural world. Our use of natural resources, need for space to sustain population growth, and introduction of invasive species may all be included as unexpected ways of changing the world around us.

Sent in by
Dawn Valentim
Museum of Natural History and Planetarium
Providence, RI


Teacher's Guide
Methuselah Tree
BUY THE VIDEO PROGRAM OVERVIEW VIEWING IDEAS CLASSROOM ACTIVITY IDEAS FROM TEACHERS RELATED NOVA RESOURCES INTERACTIVE FOR STUDENTS
   

Support provided by