Eco-columns: An Extended Lab Investigation
Purpose:
The goal of this lab is to simulate ecosystems in an effort to learn about ecosystems in the real
world.
Part 1: Set-up your eco-column
In your group
1. Identify what you are trying to discover with the eco-column. Look over the assembly
diagram to understand each chamber.
2. Decide what background sources of information you will use (textbook, other
references).
3. Decide what components to include in each section (organisms, type of soil, etc).
See back of eco-column assembly diagram for ideas.
To be done individually
4. Write a hypothesis for each of the four habitats: aquatic, decomposition,
terrestrial, and predator/prey.
5. Sketch a diagram of your eco-column and identify the biotic and abiotic
factors present in each habitat.
6. Draw the (potentially connected) food webs you anticipate taking place within
your eco-column. Make an effort to identify the species you have added as
specifically as possible. If an organism is unidentifiable, include a diagram of
it (use magnifying lens or we can get a microscope to observe your organism).
Part 2: Observation and Data Collection
Each week you will make observations of your eco-column. Each observation should
include:
 Date of observation/ measurement
 Number of days your eco-column has been running
 pH - water
 Temperature – water
 Dissolved Oxygen content of the aquatic chamber
 Qualitative observations – turbidity, plant growth, decomposition rate, fish
health, odor, predator/ prey interactions, etc.).
 Additional measurements as conducted (analysis of N-P-K content, etc.).
Part 3: Lab Write Up
Part of the scientific method involves disseminating what you have learned. You will do this
through a lab report following guidelines provided to you. Make sure to keep good records
of your observations and data during the investigation so that you are not missing anything
when it comes time to write up your report.
Eco-column Write-up Guidelines
Your lab report should be typed and double spaced (1.5 is OK)
1. Write a hypothesis for each of the four habitats: aquatic, decomposition,
terrestrial, and predator/prey. Your hypothesis should state what you think
will happen in each one of these chambers or ecosystems. Briefly describe
why you think this will be the case.
2. Draw a diagram of the column and identify the biotic and abiotic factors
present in each habitat. Put in procedure section of report. Your ecocolumn has a unique structure. Your diagram should show the column and
what is in each chamber. You can list the biotic and abiotic factors along the
side or in separate paragraphs.
3. Draw the (potentially connected) food webs you anticipate taking place
within your eco-column. Make an effort to identify the species you have
added as specifically as possible. If an organism is unidentifiable, include a
diagram of it (use magnifying lens or we can get a microscope to observe your
organism).
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
Draw a diagram of your web with organisms clearly labeled with the common and
scientific name (if you can identify the species). Ex. Elodea canadensis (note it is
italicized).
Identify the role of each organism by putting one of the following letters beneath
the name of the organism:
a. P – Producer
b. C – Consumer
c. D – decomposer
d. S –Scavenger
 Draw energy arrows to connect the energy source to the organism that obtains
the energy. For example, from the sun to algae in the water, or from the
secondary consumer to a tertiary consumer that eats the secondary.
 Within your food web, clearly distinguish three separate food chains. For
each separate food chain label at least two levels of consumers and the overall
trophic levels.
 Write a discussion of your food web that includes the following:
o What are the top level consumers in your eco-column
o What would happen to these consumers if all the primary consumers
were to die?
o If the secondary consumers in one of your food chains consumer 4,200
kcal, what amount of energy would you assume was available to the
primary consumer? Amount of energy might be available to the
tertiary consumers?
o What would happen if the decomposers were removed?
o What do you think is the more resilient (i.e. damage resistant,
fluctuations in food or populations, etc.), a food web with few species
or one with many species? Explain your answer. Discuss both if you
can think of arguments to support both.
Write up instructions
It is your job to clearly and neatly present the information about your eco-column to your
reader. Your report should include each of the sections below (plus a good title). The meat
of your report should be your analysis and conclusion. Don’t just answer the questions, use
the write up as an opportunity to deepen and demonstrate your knowledge and ideas. This lab
will be treated more formally and thus needs to follow lab write-up guidelines supplied to
you.
Background Information
What is an eco-column? Why is it a useful tool? How is it like or unlike an ecosystem n the
real world? Is it a closed or open system? These questions are intended to get you started –
you can use other info you have gathered or from the text.
Hypothesis:
Briefly summarize the hypothesis you made regarding each chamber or section of your
column. How did your actual eco-column results compare to each of your hypothesis?
Results (data –Just the facts):
 Include a table with your eco-columns data for the major testing sessions and
attach the daily observation log
 Include the qualitative information from the disassembly of your eco-column
and results from you soil test.
 Did you discover unexpected organisms (fungus, new microorganism, insect,
plant, etc)? Did you not see any new organisms? Be specific on where you
looked and hat you found.
 HINT!! Include a before and after table that summarizes the kind and number
of organisms initially (upon set-up) and then at end of the lab (disassembly).
Analysis
Discuss the data for your eco-column with regard to your set-up. What does your data say
about what has been going on in your column?
What conclusions or generalizations can you make about the eco-column as a system and
what connections can you make to other natural systems?
Choose one nutrient cycle (C, N, or P) and diagram and explain how you think it would
occur in your eco-column. Be careful not to include aspects of these cycles that wouldn’t
occur in your eco-column. Discuss how your selected biogeochemical cycle affected the
organisms living in your column.
Conclusions:
What conclusions can you make about your eco-column? What connections can you make
between the eco-column and a natural ecosystem or biotic community?
More information about your eco-column lab report
Make sure to include all your weekly observations as raw data. All observations should be
properly dated (include the date of your eco-column set-up) and any and all changes or
alterations that were made must be dated and described. On your observations, keep an
ongoing count of the number of days you eco-column has been functioning.
Identify the pH, Temperature, dissolved oxygen (DO), nitrate, and phosphate content of your
aquatic habitat and the point during the experiment when those measurements were taken.
You should also include any comparison data from other teams’ eco-column data. Look for
such things as plant growth, decomposition rate, water turbidity, etc.
Conclusion and analysis: This is the most important part of the report.
Some considerations to include:
 Identify food chains and webs in each habitat.

Identify any biogeochemical cycles
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How did each habitat affect each other? Were there large differences between
yours and other eco-columns in the classroom? If so, why do you think this
occurred?
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Identify roles of various biotic factors including decomposers, producers,
consumers, etc.

Identify and describe changes that occurred in your column (i.e. water went
from murky to clear) and include why you believe such changes occurred and
their implications in terms of the health of your ecosystem.

Discuss the similarities and or differences between your artificial ecosystem
and the ones in nature.

What kinds of niches were available to various organisms and did you notice
any instances of competitive exclusion? Did you observe the law of tolerance
in action? Were there limiting factors in your habitats?
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Did you observe any form of succession taking place in your or other’s ecocolumns?
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How did the plant life respond? Why do you think it responded this way?
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Were there color changes in any of the habitats (yellow, white, red, blue, etc)
if so, what do you think caused the changes?

Comment on the stability and sustainability of the various eco-columns in the
classroom. Do some appear more stable or resilient than others? Discuss why
you think this is so.