- Jenny Shoener
Lab Partners: Garrett, Jilda, & Ying
The purpose of conducting this experiment was to see an overview of how an ecosystem works. Also to view how organisms and the environment interact to carry out a functional system. While observing and experimenting, it would show how the cycles work together along with organisms living in the ecosystem effect the water quality. This experiment was purposeful to show how water quality and soil can be tested and give evidence and proof of how the cycles such as carbon, nitrogen, and water would work alongside the organisms living in a specific ecosystem.
The Ecocolumn was constructed on September 12th by cleaning, cutting and constructing according to the directions that were given. It was measured throughout a set of twelve weeks approximately. The bottles were cut in three different sections and were put together to form different chambers. The three different biomes were created including an aquatic, decomposition and a terrestrial habitat. In the decomposition chamber a potato, banana peel and other scraps were placed for decomposition. Soil that contained a more clay composition and organisms were brought in from outside sources to form the terrestrial habitat. Two spiders, a slug and a caterpillar of some sort were places into the chamber for interaction. Pond water was brought in from an untreated pond and was placed in the aquatic chamber for testing. During the weeks of observation, we tested the water quality and any biome changes. For the water quality, turbidity, dissolved oxygen, pH and temperature for exact number measurements were tested. As far as physical features, the odor and color was also recorded. Turbidity was measured by placing water into a glass and placed into a machine that electronically measured the turbidity. A probe that was connected to a sensor tested dissolved oxygen and the numbers would display on a screen in measurements of milligrams per liter. The probe had to be kept in movement to move around the water and oxygen. Temperature was tested the same way as far as using a probe, but it was measured in degrees Celsius and was meant to keep still. The acidic count, or pH, was measured also measured by using a probe. The odor was detected by opening up the flap created to allow access to the water and smelling it. Color was determined by sight and how transparent it was. At the beginning of the experiment, there were organisms in the decomposition and terrestrial chamber, but as the weeks progressed on and the ecocoloulm was cleared to be sustainable enough to add an organism into the aquatic chamber, there was a gold fish added. Over the twelve week stretch of experimenting, observing and testing, there was a total of five measurement days. They were spread out to see how it changed over time.
1. Identify two Food Chains or Food Webs in each of your habitats (chambers). Use arrows to illustrate these food chains and food webs; complete sentences are not required. Use extra paper if needed.
Aquatic Chamber – 1) Duckweed ï‚® Gold Fish 2) Bacteria ï‚® Gold Fish
Decomposition Chamber – 1) Compost ï‚® Flies 2) Flies ï‚® Spiders
Terrestrial Chamber – 1) Flies ï‚® Spider 2) Plants ï‚® Slug
2. Identify and briefly discuss the biogeochemical cycles which are taking place/which are present in your EcoColumns. Do not merely state that “they are all present”; instead, provide more specific information.
Water Cycle – How water gets recycled and put back into the system through several steps including evaporation, transpiration, precipitation, etc. With the ecocolumn, the water in the aquatic chamber evaporates to the terrestrial chamber and then to the decomposition section. Eventually, the water would seep back into the aquatic chamber, carrying along with it soil, nutrients and other particles.
Carbon Cycle – How carbon is recycled and put back into the system through respiration and photosynthesis. Carbon Dioxide was created from all chambers through all the organisms.
Nitrogen Cycle – How nitrogen is recycled and put back in the system through organic matter, air, consuming, and getting rid of waste. The nitrogen found in the food would be consumed by the organisms, then would be digested and exit their body enriching the soil, further going down into the remaining chambers, ending up in the aquatic.
3. Is your ecosystem column a closed or open system? — or is it something in between a closed or open system? Explain how this (closed, open or other) influences the ecosystem column overall.
The ecocolumn is both and open and closed system. As much as it is closed and maintained by itself, there is a little bit of interference and disruption when testing soil and checking the water quality; along with adding more organisms as the experiment went on. That could have possibly changed the cycles and how the ecosystem interacted as a whole.
4. What kind of niches are available/present for the various organisms in the column? Be specific, descriptive, and use terminology that is pertinent to the topic.
Decomposition Chamber Niches –The two spiders climbed from the terrestrial chamber to the decomposition chamber and made a niche in the very top of the bottle by spinning a web.
Terrestrial Chamber Niches – The Slug buried itself in the soil, while the caterpillar climbed on a branch.
Aquatic Chamber Niches – The fishes just swam around intertwining with the duckweed and aquatic plants placed into the chamber.
5. Discuss evidence of ecological succession taking place in your column (or in the column of another lab group if you have not observed any signs of succession in your column).
When the pond water was first placed into the water chamber when constructing the ecocolumn, there was no duckweed in the water, but as time went on duckweed became present due to an unknown bacteria and special conditions. In another ecocolumn, the water turned from clear to black in a matter of a few weeks due to excessive nutrients.
6. Discuss the stability and sustainability of the ecosystem columns in the lab, including your own.
As far as stability and sustainability for the other ecocolumns it fluctuated quite a lot. One group’s water turned completely black because of the excessive nutrient content also known as eutrophication. My groups’ ecocolumn was stable and sustained up until the very end. At the end of the experiment, our dissolved oxygen dropped from 7.0 mg/L to 3.0 mg/L.
7. Discuss three trends or patterns which stand out as you think back on the data which you have been recording for 6 weeks. These trends or patterns should apply to the water quality tests or other observations which you have made over this multi-week time period. Briefly discuss these three trends or patterns, providing possible explanations based on environmental science principles.
1) The temperature stayed almost constant throughout the whole experiment. Most likely due to the fact that since this was more of a controlled experiment, it stayed under room temperature through the experiment.
2) The dissolved oxygen levels stayed constant through the whole experiment up until the very end. This is could most likely be due to the rainy, cloudy weather and no sun shining through the window, reaching the column to dissolve the oxygen. Also could be due to the duckweed that became present along with the other plant that was placed in the aquatic chamber because when there are too many plants, oxygen will become little to none when bacteria break them down after they have died.
3) The pH, or acidic levels stayed on average constant throughout the ecocoloumn experiment. This could be due possibly to the stable encirclement of carbon dioxide.
8. Explain what eutrophication refers to and how this occurs. Apply this explanation to your ecosystem column. How might eutrophication take place in your column? Explain fully.
Eutrophication refers to excessive amounts of nutrients in a body of water. Eutrophication could take place in the ecocoulumn from the runoff of the soils nutrients because of the cycles taking place within the ecocolumn, more importantly the water cycle that is occurring.
9. Pick another group in your class. How do your data compare to theirs? Brainstorm some causes/reasons for any differences.
Compared to Julius, Maggie, Mariah and Alondra’s group data, our data is far different. While our water had a slight odor to it, their water was described as smelling like sewer. Their turbidity was mostly above 100, whereas our turbidity levels were in the 30’s and 40’s. Our water was almost 100% clear, but their water was pure black due to excessive nutrients. Their dissolved oxygen was on average 1.0-2.0, but ours was 7.0 on average. Some causes or reasons for the difference could be the source of where we got our water. Their water was taken from a lake, whereas our water was taken from a pond.
10. Finally, address any sources of error in this lab. This should be narrated in a “cause and effect” manner and talk about specific problems. A good example would be “water did not drain from the terrestrial chamber so …” while a bad example would be “we messed up the measuring one day.”
Some conflicts we encountered was during the experiment, the dissolved oxygen levels went down and then caused a gold fish died. Then later on one of the two spiders had died. Other than that, there was nothing that was much of an error on the ecosystem part.
In conclusion to this experiment, I saw first hand a similar representation of how an ecosystem interacts and changes as time goes on. From viewing on the outside, I was able to see how the soil and water quality fluctuated and adapted to what was occurring inside the ecosystem or ecocolumn. Prior to the experiment, I did not know how the quality of water or what was living in an ecosystem related or worked together. I learned that by what is in the water or compacted in the soil, directly correlates to how the ecosystem changes and adapts. For example, I always knew the water, carbon, and nitrogen cycle were important, but I never realized the effect they had on the water quality or how organisms helped break things down and keep different levels at stable positions. I believe the most important finding of this project is how the interaction of all the different cycles and roles organisms play in an ecosystem affect each other.
Houston, H. (2013, September 24). Interview by Shoener Jenny . Ecocolumn information.
Houston, H. (2013). Water quality notes. Unpublished manuscript, .
ISECA. (n.d). What is eutrophication . Retrieved from http://www.iseca.eu/en/science-for-all/what-is-eutrophication