OBJECTIVES
The students will:
1. Observe characteristics of prairie grasses and forbs to
help identify them.
2. Comprehend the importance of prairie plant roots as an adaptation
to drought and soil formation.
BACKGROUND
Prairie Grasses and Forbs: When many people think of
the prairie, they think of tall grasses and treeless horizons.
In and among the grasses, however, are forbs (prairie wildflowers)
that add a continually changing garden of color to the prairie.
The shortest forbs bloom in spring before the grass becomes
tall and shades them. Plants such as a pasque flower, prairie
smoke and shooting star add a splash of color, then quietly fade
as the summer grass becomes taller. As many as seventeen new species
of forbs begin to flower each week. Each group of flowers is generally
replaced by taller sun-loving plants. By fall, some flowers stand
as tall as ten feet.
The leaves of many prairie plants are slender, finely divided
and held vertically, which exposes less surface area directly
to the sun. Grasses have this characteristic. Some plants have
rough surfaces of fuzzy hairs on the leaves or stems for self-shading.
Almost all prairie plants have very deep root systems. These are
adaptations for the prairie environment: less than 30-36 inches
of rain per year, extreme heat in summer and bitter cold in winter,
high winds, periodic drought, and sweeping fires.
Roots: Some of the richest farmland in the world was once prairie.
The roots of the prairie plants not only helped the plants survive
both drought and fire but also were largely responsible for making
this soil.
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MATERIALS
* Book, Addie Across the Prairie
- Journal
- Prairie mural construction materials (See Ongoing Activities:
Prairie Mural., p.6)
- Class set of styrofoam coffee cups
- Small bag of potting soil
- Water
- "Sidewalk dirt" collected by students
* Student pages
- Prairie Grasses
- Roots
* Teacher pages
- Prairie Forbs Background (May be used for students too.)
- Prairie Grasses Answer Sheet
- Roots Answer Sheet
* Transparency Masters
- Prairie Grasses
- Spring Forbs
- Summer Forbs (2 sheets)
- Prairie Grass Root System
- Prairie Burrows
Starred (*) materials are included in this packet.
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VOCABULARY
adaptation: Ways that a living thing is special to allow it
to live more successfully in a certain area.
drought: A long time without rain.
ecosystem: The living and non-living things cooperatively existing
together.
forbs: Prairie wildflowers.
humus: A brown or black substance resulting from the partial decay
of leaves, roots, and other vegetable matter; organic part of
the soil.
perennial: Plants that come up from roots and other underground
parts year after year.
sod: A surface layer of earth containing grass and their matted
roots.
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PROCESS
Observing, identifying, classifying, comparing and contrasting,
forming models.
PROCEDURE
- Distribute the prairie grasses student page and help the
students do the four work steps.
- Use the grasses and forbs transparencies to begin the prairie
mural. As forbs are put on the mural, use the Prairie Forbs
Background sheet for information about the plants and their
flower color. This sheet may be used as an informational handout
to students.
- Have students read the Roots student page.
Use root system transparency to elicit how the roots form soil
and help the prairie survive.
- Instruct each student to collect a sample of 1/3 cup of dirt
from sidewalk cracks, along driveways or other paved areas where
seeds could collect. This can be done for homework or at school.
However, the results are more interesting if different students
collect samples from various locations.
- Have each student make a seed pot by filling a styrofoam
cup with potting soil 1/2 full, adding the "sidewalk"
dirt and watering. Have the student label the cup with their
name and where they collected their dirt sample.
- Have students predict whether they expect any plants to grow
and if so what kinds.
- Monitor seed cups and compare results with predictions.
- Continue ongoing activities.
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EXTENSION ACTIVITIES
- Compare and contrast prairie plants to plants found on the
school lawn or an open field.
- If space allows, make a second mural of the underground prairie
showing the roots. Simulate roots with string, twine, or rope.
This mural can also show the correct size of animal burrows and
can have the animal in the burrow or near its entrance. A transparency
has been provided to show burrows for some of the prairie mammals.
INTERDISCIPLINARY CONNECTION
Art, mathematics, social studies.
ASSESSMENT
(Answers are italicized and refer to student pages indicated
below. Answers are also included on the corresponding Teacher
Answer Pages.)
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Prairie Grasses (p. 23)
Name two differences among grass species (Height, structure,
soil type.)
-
Grass
|
Soil
|
Height
|
| Big bluestem |
Moist |
8' |
| Little bluestem |
Dry to moist |
2 to 4" |
| Needlegrass |
Dry |
2 to 4' |
| Side-oats grama |
Dry |
1 to 3' |
| Switchgrass |
Moist |
3 to 6' |
| Indian grass |
Moist |
4 to 8' |
| Nodding wild rye |
Dry to moist |
3 1/2' |
| Prairie dropseed |
Dry |
2 to 3' |
Grasses identified from left to right, top row followed by bottom
row:
Needlegrass, Switchgrass, Indian grass, Side-oats grama
Big bluestem, Nodding wild rye, Prairie dropseed, Little bluestem
List three things that grasses contribute to the prairie ecosystem.
(Roots anchor the soil preventing erosion; Roots combine with
soil to form sod which absorbs moisture; Nutrient elements in
dead roots provide energy for other plants.)
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Roots (p. 28)
- What is humus? (The decayed roots of plants)
- List at least two ways that humus is good for the soil. (It
contains nutrients from the rotted roots, making the soil fertile.
It loosens the soil so roots can grow through it more easily.
Humus helps to hold water in the soil.)
- List at least two ways the long, perennial roots help prairie
plants. (Roots go deep into the soil to get water. They store
food so the plants can survive drought. The prairie plants spread
by sending up new shoots from the roots. The long roots help
the plant live through the winter.)
- List possible reasons to explain why pioneers decided to
farm the prairies?(Possible answers include: It was a lifestyle
with which they were most familiar and previously successful.
They were not aware of the amount of hard work it involved or
the value of the prairie.)
- Explain the differences between the grass in your front yard
and the grass in the prairie. (Possible answers include: Grass
in the front yard was planted by man and is not native to the
area. It is all of one variety and has shallow roots. Grass in
the prairie was originally planted by nature and is native to
the area. There are many varieties present at one time and all
have very deep roots.)
- Make a plan to measure how many roots are in a soil sample.
(Possible answers may include: washing dirt off roots and
weighing, counting roots directly.)
- As a pioneer, explain why it was necessary to plant crops
on the prairie. (It was the only method of producing food
that they had experience with, and they needed food to survive.
The pioneers may not have had any other alternatives at the time.)
The prairie grasses student page may be graded or used as the
basis of discussion. Students can be assessed on their individual
part of creating the mural, effort, artistry, oral or written
reports and overall completion of the class project.
The following list suggests journal ideas or topic questions.
- Describe the differences between the grasses and forbs by
"interviewing" one of each.
- Ask questions such as, "How long have you lived in the
prairie? How tall do you hope to get? Do any other plants or
animals depend on you? How do you survive in the hot summer sun?
What is your greatest fear? What do you want to do when you grow
up?" See Journal Ideas for Day 2.
Program Contact: Spencer
Pasero - spasero@fnal.gov
Web Maintainer: ed-webmaster@fnal.gov
Last Update: November 16, 2000
http://www-ed.fnal.gov/samplers/fba/fba_master.html
