Ecocolumn Lab
This lab will provide opportunities to investigate the components of different ecosystems, in miniature. The conditions required for
the sustainability of the ecosystems, and the interconnections between them will be studied. This is a long-term study that will not be
completed until the end of the semester.
Materials (to be used on day 1 of the lab)
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2-liter clear plastic bottles (7) with the labels removed
completely*
2-liter bottle caps (3)*
dissecting needle
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Bunsen burner
scissors
sandy soil
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sand and gravel
sticks and/or twigs*
fist-sized insoluble rock*
Materials (to be used on day 2 of the lab)
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clear packaging tape
a large diameter straw
a small diameter straw
Materials (to be used after the column has reached preliminary equilibrium)
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pond water*
duckweed*
leaf litter, grass clippings, banana peel, etc. (for
decomposition chamber)*
seeds and/or viable plant cuttings*
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selected aquatic plants – anacharis, elodea, hornwort,
green hedge, ludwigia, etc.*
terrestrial fauna – spiders (for predator/prey chamber),
pillbugs, earthworms, earwigs, fruit flies, etc.)*
aquatic fauna – small fish (danios, white cloud minnows),
small aquatic snails, etc.*
* Students will bring these materials to school.
Procedure
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Construct an ecocolumn according to the diagram on the back of this paper.
Add soil, sand, and gravel to the aquatic and terrestrial chambers as instructed in class.
Add leaf litter, grass clippings, and a banana peel to the decomposition chamber as instructed in class.
Add clean gravel and a clean fist-sized rock the aquatic chamber, and then volumetrically calibrate the aquatic chamber at 100-ml
intervals as pond water is added.
5. If necessary, allow the soil in the terrestrial chamber to dry. Add seeds or viable plant cuttings to the terrestrial chamber.
6. Add several sticks and/or twigs to the predator/prey chamber, and then add two or three captured spiders as instructed in class.
7. Measure the dissolved oxygen (D.O.), pH, and temperature of the aquatic chamber, and then add aquatic plants to the aquatic
chamber. Measure the D.O., pH, and temperature of the aquatic chamber the next day, and continue to regularly monitor the D.O.,
pH, and temperature of the aquatic chamber.
8. After the plants in the terrestrial chamber are growing successfully, add terrestrial fauna to the terrestrial chamber.
9. After the plants in the terrestrial chamber are growing successfully, and the D.O., pH, and temperature of the aquatic chamber are
stable add aquatic fauna to the aquatic chamber.
10. Continue to regularly monitor the D.O., pH, and temperature of the aquatic chamber.
11. Perform additional water quality tests as instructed in class.
Data Analysis
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In the lab notebook, keep comprehensive records of all work on the ecocolumn.
Observe and collect data from your ecocolumn until the end of the semester.
The lab notebook will include the procedure, all observations, data (tabulated), charts, and graphs.
At the conclusion of the lab, a thoughtful, scientifically valid, and collaborative discussion will be completed.
Questions
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Explain the changes you observed in your ecocolumn.
Calculate the growth rate for all observable species in your eco-column. Growth rate = (Crude Birth Rate + Immigration Rate)
– (Crude Death Rate + Emigration Rate).
Identify the type of organisms in your ecocolumn that exhibited type I, type II, and type III survivorship curves.
Identify the species in your ecocolumn as r-selected or k-selected species.
Identify specialists and generalists in your ecocolumn.
Identify one producer, primary consumer, secondary consumer, and decomposer in your ecocolumn.
What were the limiting factors that restrained population growth in your ecocolumn.
Explain the food web of your ecocolumn.
Do you think there is a keystone species in your ecocolumn? Why or why not?
What biome does your ecocolumn most closely resemble? Defend your choice.
Explain how carbon, nitrogen, phosphorus, and water cycle through your ecocolumn.
What are the differences between a real ecosystem and your ecocolumn? Can a large ecosystem really be managed?
Biosphere 2 was a sealed experimental ecosystem in the Arizona desert. It was a failure. What advice would you give to
future ecocolumn builders?
Diagram of the Ecocolumn
Predator/Prey
Chamber
Small holes allow
fruit flies to enter
Large diameter
straw
Decomposition
Chamber
Small diameter
straw
Terrestrial
Chamber
Small holes in cap allow water
to drain slowly
Aquatic
Chamber
Permanent marks indicate
volume every 100
milliliters
arge
diameter S
Diagram of the Ecocolumn
Predator/Prey
Chamber
Small holes allow
fruit flies to enter
Large diameter
straw
Decomposition
Chamber
Small diameter
straw
Terrestrial
Chamber
Small holes in cap allow water
to drain slowly
Aquatic
Chamber
Permanent marks indicate
volume every 100
milliliters