|
"It's
All in the Rings" Lesson Plan
Keywords: tree
growth, tree health, tree anatomy
Prepared by: William Lundvall, Indian Valley High School
Grade Level: seventh through tenth grade (middle school, high school)
Total Time for Lesson: 50 minutes
Setting: classroom
Concepts to Be Covered
- Impact of nature and
man on tree growth
- Trees are resilient:
they respond to adversity in order to survive
Goals for the Lesson
- Students will become
aware of how trees grow.
- Student will analyze
growth rings to see how plants adjust to adverse conditions in
order to survive.
- Students will learn
more about the anatomy of a tree.
Teaching Model:
Focus, Explore, Reflect
Academic Standards
Addressed: 4.3.7; 4.5.10; 4.7.7; 4.7.10
Introduction
This lesson is designed
to explore the growth of trees. Although trees do not have nervous
systems and therefore lack nervous responses, they certainly do
respond to changes in their environment. We will look inside a tree
and try to arrive at some conclusions about changes in growth patterns
in it's life history.
Focus Phase (15 minutes)
Pass out handouts and use overhead transparencies of tree cross
sections to identify the internal anatomy of a tree. Discuss the
value and importance of each part with the class. Analyze the life
history of a hypothetical tree. (See data
sheet, tree layers, and tree
rings.)
Explore Phase
(20 minutes)
Preparation
Prior to class, have
your woodshop teacher saw a small log (preferably a hardwood at
least 20 to 25 years old) into 1-inch sections. Sand or plane the
surface so that it is smooth and the growth rings are clearly visible.
Procedure
- Students should work
in pairs. The only materials they need are a ruler, a section
of the tree, and a data sheet to record their observations.
- Count the rings and
determine the age of the tree.
- Measure the diameter
of the each ring in millimeters (be sure to take measurements
in several places along the growth ring, then average them for
accuracy). Record the answers on the data sheet.
- Using the largest
as excellent and the smallest as poor, rate the tree's growth
for each year of its life. Rate the growth as excellent, good,
fair, or poor. Record the choices on the data sheet.
- Each team should record
their results on the board or overhead transparency.
Reflect/Conclusion
Phase (15 minutes)
Once all the data is
recorded, provide students with the following information:
- Species of tree
- Where the tree was
growing
- Weather data for the
years the tree lived (use Internet sources)
- Other possible factors
such as plant diseases, insect infestations, natural disasters,
and human-made situations that could have made an impact on the
tree's growth.
Have each student write
a report that indicates what they feel caused variations in the
tree as it grew each year. There is no absolutely correct answer,
but students should be able to see that plants do respond to changes
in their environment, both natural and human made.
References
Hansen, Robert S., and
James C. Finley (1996). Trees
+ Me = Forestry. University Park, Pa.: The Pennsylvania
State University.
Ketchum, Richard M. The
Secret Life of the Forest. American Heritage Press. 1970.
|
