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Probing
Questions
On a brisk,
overcast day a busload of budding scientists embarked on a field
trip to Spruce Run Environmental Education Center. Spruce Run
is located on 50 acres of land donated to Columbus Public Schools
by Robert and Dorothy Patton in 1974. It is well suited for outdoor
education with a variety of geologic features, including a succession
plot, woodland, meadow, shale creek bed, flood plain, and ridge.
A portable classroom equipped with electricity and running water
serves as a shelter and area for indoor activities.
As the students
emerged from the bus, the air was filled with excitement and
anticipation. This was no ordinary field trip. These urban scientists
were going to collect data with science probes that would help
them find the answers to questions posed about the differences
in the ecosystems of a stream, forest, and meadow. Which type
of soil supports more plant life? Why do you think the habitats
have different pH levels in the soil? Are there different temperature
readings among the ecosystems? After being divided into groups,
students were given worksheets (see side bar) and rotated through
stations where they learned about the characteristics of ecosystems,
soil pH, difference between air and ground temperatures, and
how to use probes. Laptop computers were set up in the shelter
house to manipulate the information. Prior to this scientific
expedition, students were prepped with background information
on habitats, pH, making predictions, and soil composition. Websites
provided valuable background information and contributed to the
prior knowledge necessary for scientific inquiry.
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Where to Buy Science Probes
Although the students in this article used the Pasco Datalogger
and sensors, there are several companies that manufacture probeware
for schools. Many of the products are sold in bundles targeted to
specific grade levels and subject areas.
Pasco
In the classroom or out in the field, the Passport Xplorer Datalogger
allows you to plug in sensors and record over 100 sets of data and
store 50,000 measurements. DataStudio lite and Ezscreen software
are included in the bundles. Passport Xplorer Datalogger and sensors
are compatible with Windows and Macintosh operating systems and connect
via a USB connection.
Vernier
Not only can you use LabPro with a computer, but you can also use
it with a Texas Instruments Graphing Calculator, or as a stand-alone
data collector. The Vernier LabPro stores 12,000 data points. It
includes the DataMate calculator program, but Logger Pro software
for computers is sold separately. You have a choice of using LabPro
with Windows or Macintosh computers, connected to a serial port or
USB port.
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Prerequisite
Skills/Knowledge - Surprising Soil
Students should
have an understanding of pH and make predictions based upon their
prior knowledge and experiences.
Different soil
types (different varieties of plant life that, in turn attracts
and supports different types of animals. The pH of the soil can
dictate what types of vegetation and animals inhabit a particular
area. pH measures whether something is an acid or alkaline, or
neutral. If the pH is 7, it is neutral; if the pH is above 7,
it is alkaline; and if it is below 7, it is acid. pH levels in
the range of 0-4.0 are typically too acidic for most plants;
6.0-8.0 is the range most plants do best; 8.5-14 is too alkaline
for most plants. Below are examples of pH levels preferred by
certain plants:
4.0-5.0
Strongly Acidic
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6.9-8.0
Neutral
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5.0-6.0
Mildly Acidic
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Mountain
Ash
White Cedar
Venus Flytrap
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Buckeye
Squash
Peas
Beans
Ash
Cherry |
Apple
Strawberries
Spruce |
Students should
have a deep understanding of soil composition and characteristics.
McGraw-Hill Science Text, pp. 434-437
Students should
have an understanding of the use of magnifying lenses, coffee
cans as core samplers, filtering containers, measuring in ml,
stop watches, and litmus or pH indicators such as probes.
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Field
Trip
During the
field trip to an outdoor area, have students pair up and rotate
through three stations: Forest, Stream, and Meadow. Use the Soil
Sample Worksheet or the Probe
Worksheet to record data. This activity is desgned for scientific
probes, but can be adapted to meet your needs.
Follow up in
the classroom by having students create
spreadsheets, graphs, and charts. What did they discover from
the data collected?
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Absorbing
Answers
Our young scientists
expertly created an Excel spreadsheet of the data collected from
pH and temperature samples. They constructed graphs and charts
of temperatures from the woodland, meadow, and stream so they
could compare the results and draw conclusions. Another chart
compared the different pH readings from each of the ecosystems.
They found that air temperatures were very similar for each location
and the difference between the surface temperature and the ground
temperature ranged between 4 and 5 degrees. The study that captivated
students the most was pH. They discovered that pH was more acidic
under trees in the woodland than in the open meadow and the stream
was somewhat acidic due to leaves falling into it. Each student
kept a folder and disk of the results to compare with those of
the next excursion in the winter. Who knows what science treasures
students will discover on their next outing.
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Web
Links
Ask
the Answer Worm!
Have you ever
wondered how many years it takes to form one inch of soil? S.K.
Worm answers frequently asked questions about soil in a humorous
way. This site is brought to you by the United States Department
of Agriculture and is geared to elementary students.
Biomes
of the World
Basic concepts
about biomes and ecosystems around the world are presented along
with photographs and illustrations. You can find facts and definitions
about deserts, forests, grasslands, streams, wetlands, and oceans.
The site is easy to navigate and suitable for elementary and
middle school students.
pH
Factor
What do cabbage
water and litmus paper have in common? Paper strips dipped in
cabbage water and dried can be can be used as an indicator of
pH. Predict the pH of substances, and then click on the item
to see where it falls on the pH scale. In addition to activities
and lessons, there is a clear explanation of water and pH. This
is a great starting point for elementary and middle school students
to learn about pH.
Soil
Climate Analysis Network
Compare the
air and soils temperatures your students gather with other areas
of the country in real time. Sorting out relevant information
may be a bit challenging at first because so much other data
is included in the tables. However, once you understand the column
codes, you will be able to find the information for your comparison
study. All temperatures are reported in Celsius. High School
students can take this a step further by comparing other soil
data like moisture and salinity.
Soil
Investigation
GLOBE is a
worldwide hands-on, primary and secondary school-based science
and education program. The program offers students the opportunity
to take measurements and report their data through the Internet.
Teachers can take advantage of the many teaching guides, Web
chats, and videos on scientific topics. All GLOBE texts and other
materials can be downloaded or copied without charge. The materials
on soil investigation are comprehensive and include activities
that teachers can implement readily into the curriculum. From
Bricks to Mud Pies, A Field View of Soil – Digging Around,
and Soil the Great Decomposer are a sample of the activities
covered. Teachers and other educators who wish to lead students
in GLOBE need to attend special workshops in order to fully participate
in the program.
USDA
Soil Facts -- definitions of soil and soil survey, information on careers, some basics on soil formation and classification, soil science glossary, and regulations for moving soils
Water
Quality Program: Streams
Why is the
temperature of a stream important? How does pollution affect
the pH in water? These and other questions are answered. Nutrients,
dissolved oxygen, suspended solids and turbidity, are also presented.
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