Lesson
Overview:
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The Carbon:
Element of Surprise video will introduce students to carbon
cycling and the general chemistry concepts involved in the process.
Students
will investigate how neighborhood trees recycle carbon through the
fast track by making observations throughout the school year. (The
activity can instead be adapted to observe native plants or plants
grown in the classroom, such as Wisconsin Fast Plants.) Students will
plant a seedling or select a young tree to examine for changes such
as growth, leaf production, flower production, area covered by shade,
leaf mass, or leaf area and make inferences about the carbon cycle.
They will use data tables and graphs to display and analyze their data
and draw conclusions about changes in the carbon cycle occurring throughout
the year. |
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National Science Education
Standards:
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Content Standard A: Science
as Inquiry
Abilities Necessary to do Scientific Inquiry
Content Standard C: Life Science
Matter, Energy, and Organization in Living Systems
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| Excellence
in EE-Guidelines for Learning: |
Strand 1: Questioning and
Analysis Skills
C. Collecting Information
Strand 2: Knowledge of Environmental Processes and Systems
2. The Living Environment
B. Designing Investigations
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Key
Concepts:
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1. Scientists
design and conduct investigations to test hypotheses based on their
observations, their prior knowledge, and their understanding of the
process of scientific investigations.
2. During photosynthesis, producers (such as trees) use chlorophyll,
water, and energy from the sun to split carbon from inorganic carbon
dioxide molecules.
3. Producers then trap the
carbon into organic compounds (such as glucose) that producers, consumers,
and decomposers can use for energy and building blocks for growth,
releasing oxygen into the atmosphere.
4. Producers, consumers, and
decomposers use aerobic respiration and/or decomposition to recycle
carbon by releasing carbon dioxide from organic compounds and putting
it back into the atmosphere. |
| Objectives: |
Students will:
 design
and conduct an investigation to measure long-term changes in a
selected tree and make inferences about the fast track carbon cycle.
reach
conclusions about how changes in the fast track carbon cycle are
affected by environmental factors such as location, weather, and
seasonal changes.
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Cross-Curricular Connections:
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Language Arts:
• Communicate
their findings orally and in written reports.
Mathematics:
• Measure
changes in indicators of tree growth, such as trunk diameter, and correlate
these changes with environmental factors.
• Organize
and graph data.
Visual Arts:
• Illustrate,
using a time line, the changes in the carbon cycle that occur during
a period of observation.
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| Process
Skills: |
Observing
Inferring
Analyzing
Communicating
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Materials:
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Per Group
Measuring instruments such as meter sticks, string, weather thermometer,
tape measures, balance scales
Rain gauge
Fertilizer
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| Suggested
Time Frame: |
Several 50 minute
class periods throughout the year
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Procedure:
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- Introduce the concepts
of the carbon cycle by showing the Carbon: Element of Surprise video.
- Assign groups of students
to design a long-term investigation of the effects of different
environmental factors on the carbon cycle. They will compare input
and output of the system. Example — input is increase in mass while
output is serving as a food source for squirrels or loss of leaves.
The design should include measuring and comparing the effects of
environmental factors selected by the students such as weather,
rainfall, temperature, and fertilizer on photosynthesis several
times throughout the school year. The tree's response to these
factors might be measured as changes in leaf number, trunk diameter,
leaf mass, leaf area, area covered by shade, and height. Ideally,
measurements would be taken once a month, recorded in tables, and
graphed.
More qualitative observations including leaf color, use of the
tree by animals for food and/or shelter, and date of spring leaf
out should also be made and recorded.
Students should be able to make inferences about events in the
carbon cycle comparing the measurements over time. After careful
analysis conclusions can then be drawn and shared during class
discussions and oral presentations.
Depending on the number of trees on the school grounds options
include:
1) each group can select its own tree of a designated
species and investigate several factors, averaging the results
from all groups
2) the class can select one individual tree and
each group can measure a different factor each time.
- Students will illustrate
a food chain that includes their tree and a time line showing the
changes in their tree. These changes can be correlated with chemical
changes that occur in the carbon cycle. For example, many trees
shed their leaves during times of drought to conserve water loss.
If there are fewer leaves students may infer that photosynthesis
has decreased. Therefore less carbon dioxide is being used by the
tree to make glucose.
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Suggested Discussion
Questions:
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Which
factors seem to influence the chemical changes the most? The least?
What
effect would additional fertilizer have on the tree in relation to
the chemical changes of the carbon cycle?
How
can a tree compensate for a lack of rainfall?
Describe
how the rate of the carbon cycle changed in your tree throughout
the year.
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Further Investigations:
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Groups
can email ecology pen pals at other schools who are also monitoring
trees and exchange data and ideas.
The
class can participate in an online phrenology data exchange with other
schools by participating in online projects such as Journey North at
http://www.learner.org.
A
local forester can present information to the class about local tree
species and how they are adapted to recycle carbon in efficient ways. |
| Career
Opportunities: |
Arborist
Botanist
Forester
Land Management
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Assessment Procedures:
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Use
a rubric to assess the food chain illustration.
Students
should keep a log of all measurements and observations.
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