FOCUSED ON TREES
FF -14
SPRING 1995
Source:
Mary Hendren & Project AIMS
Objective:
To increase understanding about trees and their importance to the environment
Grade Levels: K - 3, and 4 - 6
Science Theme:
Scale and structure
Process Skills:
Observing, comparing, categorizing, ordering
Focus Words:
Cambium, heartwood, sapwood, pith, inner bark, outer bark, annual rings, circumference,
diameter, radius
Materials:
See below, under various activities
If school yard is bereft of trees, bring samples of leaves & bark
Activities:
Choose from the following activities to prepare your students for a field trip to a forest foothill site.
For Lower Elementary Grades (K - 3)
Tree age:
Materials: Potted tree seedling, measuring tape, picture of a tree cut down, tree cookies,
magnifiers, tree worksheet (use existing copies)
Flow of lesson:
How old do you think this tree is?
How tall is it now? (measure)
How tall do you think it will be when you leave___school in ___years?
How tall do you think it will be when you get married?
Does a tree grow up and out, taller and fatter or just taller?
If you see a tree cut down (picture) how can you tell its age?
(Illustrate rings with good picture and tree cookies)
Let's count the rings and find out the age of the tree.
(Let different children try.)
Why do you think the rings aren't all the same size?
Why would a tree grow more one year and not so much another year? (refer to tree chart) On our field trip
we might see the kind of tree that grows to be the tallest in the world. Can one of you read what it is?
Leaf samples:
Materials: Bay leaves, eucalyptus leaves, other leaves and leaf chart
Flow of the lesson:
Some trees have very interesting smells and we'll see them on our field trip.
(Crush California bay laurel leaf) What do you think of this smell? Some people use this leaf in cooking.
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Do your hands smell like bay leaf (pass it around)? Do you like it? (Crush eucalyptus) Same questions.
This is not used in cooking but some people use it to keep fleas away from their pets or to help them
breathe when they have a cold. If your eyes are closed, can you tell the difference between the smell of
the bay leaf and the smell of the eucalyptus? (try it out)
Bring in some other leaf smells (cedar or pine needles, non smelly leaf) Can anyone point out a favorite tree
outdoors?
Cone samples:
.
Materials: Cones from redwood, Douglas fir, different pines, and pine nuts from the store
Flow of the lesson:
Some trees have cones. Why?
Do these cones all look alike?
Do they all have the same purpose?
When the seeds are ripe and ready and the cones open up to drop the seeds, what happens to the seeds? Do they all
grow into trees?
What happens to the ones that don't grow into trees?
Who eats the seeds? How do the seeds get carried away?
Nuts.
Materials: Buckeyes, walnuts (shelled and whole), acorns, tree worksheet
Flow of the lesson:
Why does a tree have nuts?
Are nuts the same as seeds?
Who eats them? Do we eat them?
(Explain about the Native Americans eating acorns, how to prepare, that buckeyes were a secondary food source)
What kind of tree would grow if you planted a buckeye? a walnut? an acorn?
Can you find a picture of these trees on the chart?
For Upper Elementary Grades (4 - 6)
Adapt any of the above information, or use the following ideas.
Tree identification:
Materials: Pacific Coast Tree Finder, 2 students/book, cones, needles and leaves so that each group has enough for every 2
students, tree worksheet.
Flow of the lesson:
You can start out by going out to the school yard to look at some of the trees.
Trees can be broadly classified as either evergreen conifers or deciduous..
What do you think the word "conifer" means? (show the word spelled out). It means cone bearing.
Why does a tree have cones?
How do the seeds get out of the cones?
Where do seeds form in deciduous trees (inside the fruit).
Do all the seeds grow into trees?
Working with a partner, see if you can identify cone. needle and leaf samples by reading the descriptions in the
Pacific Coast Tree Finder. Place samples together that come from the same tree.
Can you figure out the tree's age without cutting it down to count the growth rings? (one inch of circumference is
about one year of growth).
Can you figure out the tree's height? (guess by comparison, or measure the length of the tree's shadow compared to
the shadow of an object of known length, such as your own height and your shadow's length at the same time of day
you do the tree's shadow). This is a good way to introduce the concept of ratios.
Inside A Tree
.
..
Materials: Tree cookies (cross sections cuts, enough for each student), tree worksheets, tree ring photos (or
drawings), tape measure, rulers (enough for every two students), magnifiers, fresh twig and leaf samples
(optional), go out in school yard to look at trees.
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Flow of the lesson:
Do trees grow up or out or both--height and circumference? Students, using a tape measure, can measure the
circumference of some of the outside trees. Measure at about chest height of a student. They will all record this on
their worksheets.
Back in the classroom
Bring in leaf samples from different trees in school yard.
How can you tell the age of a tree that has been cut down? (Practice counting rings in tree cookies)
Measure the rings. Why are some rings closer together than others?
What does that mean in terms of that year's growth?
What factors can you think of that might affect the amount of a tree's growth?
Use a student to represent a tree and ask him to stand.
Measure his circumference around the waist. Explain that "normal"' trees gain about 1 inch in circumference a year,
so this is a way of estimating a trees age without cutting it down to count the rings.
How old is the student tree? How old were trees measured in the school yard?
Explain diameter (distance across); have students measure the diameter of their tree cookies.
They can compute the the tree cookie's circumference by multiplying pi (3.14) by the diameter. Or, they can take the
circumference divide by pi (3.14) to get diameter (distance across the tree cookie). Divide the diameter by 2 to find
the radius (half the distance across).They can also just measure across with a ruler, but if you would like them to do
some advanced math, the first method is more challenging.
They can complete their worksheets and share the results as a class to fill in the graphs.
Some Other Things To Do:
.
Draw a tree and label the parts. You can make a master (see sample in kit) with nothing labeled and then have the
class label all the parts of what they remember.
Make tree ID cards (or older students can make their own tree key).
Gather walnuts, buckeyes, pine nuts or acorns and find out if they can
be sprouted in pots in the classroom.
Leaf Descriptions: (Descriptions of leaves found in the kit are taped inside the lid of each box of leaves.)
Sample:
Tan oak trees are identified by their flat leaves with fuzzy diagonal "parking space" veins, and by their acorns with
fuzzy caps. The tanbark industry and redwood logging both flourished in this area during the last part of the 19th
century. In the old tanning process, the bitter tannin was removed from oak bark, then used by local tanneries to
process animal hides for leather.
from Portola State Park -Sequoia Nature Trail Guide
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Focused on Trees
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