es 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 quarter.
Materials
To be used on day 1 of the lab
2-liter clear plastic bottles (7) with the labels removed completely*
2-liter bottle caps (3)*
dissecting needle (or nail)*
Bunsen burner
scissors
sandy soil*
To be used on day 2 of the lab
clear packaging tape*
a large diameter straw*
a small diameter straw*
sand and gravel*
sticks and/or twigs*
fist-sized insoluble rock*
To be used after the column has reached preliminary equilibrium
pond water*
duckweed*
leaf litter, grass clippings, banana peel, etc. (for decomposition chamber)*
seeds and/or viable plant cuttings*
selected aquatic plant
s – anacharis, elodea, hornwort, green hedge, ludwigia, etc.*
aquatic fauna – small fish (danios, white cloud minnows), small aquatic snails, etc.*
* Students will bring these materials to school.
Procedure
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.
If necessary, allow the soil in the ter
restrial chamber to dry. Add seeds or viable plant cuttings to the terrestrial chamber.
Add several sticks and/or twigs to th
e predator/prey chamber, and then add two or three captured spiders as instructed in class.
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.
After the plants in the terrestrial chamber are growing successfully, add terrestrial fauna to the terrestrial chamber.
After the plants in the terrestrial chamb
er are growing successfully, and the D.O., pH, and temperature of the aquatic chamber are stable add aquatic fauna to the aquatic chamber.
Continue to regularly monitor the D.O., pH, and temperature of the aquatic chamber.
Perform additional water quality tests as instructed in class.
Data Analysis
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
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?
