A portion of your grade is based on your planning for the ecocolumn. As part of the planning you need to be thinking about how matter and energy will move through your eco column.
1. What is the role of photosynthesis in maintaining the cycle of matter in the top/bottom level of your ecocolumn? Answer in separate paragraphs for the top level and the bottom level. Describe and movement of matter between the top and the bottom levels of the ecocolumn.
2. What is the role of cellular respiration in maintaining the cycle of matter in the top/bottom level of your ecocolumn? Answer in separate paragraphs for the top level and the bottom level. Describe and movement of matter between the top and the bottom levels of the ecocolumn.
3. Describe the flow of energy through the top/bottom levels of your ecocolumn. Make sure you describe the processes that transform energy in the ecocolumn. Answer in separate paragraphs for the top level and the bottom level.
Please complete the planning document to the right. Use a different color for each member of your group.
Each student should complete the prewriting questions individually.
Your group will also need to submit a food web and a pyramid of biomass/energy for both levels of the ecocolumn.
Frequently asked questions:
1. What do we turn in?
- Planning document (submit to canvas as a group - DUE WEDNESDAY @ 11:59pm)
- Inventory - Top and Bottom Levels (submit to canvas as a group - DUE FRIDAY @ 11:59pm)
- Pre-writing questions (submit to canvas as an individual - DUE MONDAY @ 11:59pm)
- Food Web and Pyramid of Biomass/Energy (submit to canvas as a group - DUE MONDAY @11:59p)
- Data collection (submit the linked document to canvas as a group - graded as individuals)
- Photos for each level for each data collection date (submit to canvas as a group)
- Paragraph responses to each of the analysis questions (submit to canvas a an individual)
2. Is there extra credit?
-2 points of extra credit will be given to students that record detailed written observations for each data collection date.
-up to 10 points of extra credit will be given to any group that, in addition to the standard eco column, builds an additional eco column with the following requirements. (3 different niches - one must be water based, 3 levels of food chain for each niches, all the same testing requirements as the regular eco column, a 1 page analysis of the sustainability of your eco column) Building and testing your additional ecocolumn cannot take up additional class time. If you are able to complete the testing and building during class time already scheduled for these activities thats fine. Otherwise you will need to schedule other times to come in and complete this work.
3. What organisms will be provided?
- Elodea: A water plant was from Lake Washington, commonly referred to as seaweed
- A pond water culture containing microorganisms such as Euglena and Daphnia.
- Hornwort: A quick growing pond weed.
4. What do the ecocolumn tests mean?
Ammonia, Nitrite, Nitrate- Maintaining a population of bacteria that convert ammonia into nitrite is an important part of aquarium water chemistry; a process known as biological filtration. Ammonia, nitrites and nitrates are all byproducts of organic waste breaking down in an aquarium, and all are toxic at some level to your fish and plant life. A significant amount of fish and plant waste can accumulate in any aquarium, (as well as uneaten food, algae, and bacteria). As in all environments, this waste needs to be broken down and either eliminated or turned into something which can be utilized by another organism. Decomposers break down the waste from plants and fish into ammonia. This ammonia is very toxic to fish and is converted to nitrite by nitrifying bacteria.Nitrite is also toxic to fish, and is converted to nitrate once again by beneficial nitrifying bacteria, however, this process can only occur if oxygen levels in the water are high enough. Nitrate is not nearly as toxic, and is used by plants or algae to help them grow
pH- The addition of acids can lower water pH. Acids come from several sources: from excess carbon dioxide via respiration, from the nitrification stage of biological filtration, and from leaching tannins in driftwood, to name a few. Most fish like a pH between 6.5 and 7.2. Sudden drops in pH can harm your fish. On the other hand, substrates or gravel containing coral, limestone, or sea shells will leach carbonates into the water, which will raise the pH buffering capacity. In saltwater aquariums, this may be desirable, but in most freshwater aquariums, you generally don't want your substrate to raise pH levels.
Soil Temperature– Of all the organisms in your ecocolumn, bacteria are the most important decomposers. There may be millions of bacteria in a gram of soil or decaying organic matter. Bacteria utilize carbon as a source of energy (to keep on eating) and nitrogen to build protein in their bodies (so they can grow and reproduce). They obtain energy by performing cellular respiration. Cellular respiration heats up the soil. If proper conditions are present (enough oxygen, nitrogen, and organic molecules), the soil will heat up fairly rapidly (within days) due to bacteria consuming readily decomposable materials. Compost piles, which are designed for the quick breakdown of organic material can reach temperatures of 75 degrees Celsius – well over 100 degrees F.
Water temperature– In IPS you learned that different objects have different specific heat capacities. This means that some objects require very little energy to heat up while others can store a lot of energy while barely changing temperature. Water has a high specific heat capacity so it can get a lot of energy without increasing in temperature. The water in your ecocolumn might change temperature as it sits in the sun or as organisms perform cellular respiration. However, unlike the soil, the water temperature should not change much. Most fresh water fish and shrimp will prefer a water temperature between 22-24 degrees Celsius.
Oxygen percent– the amount of oxygen in the ecocolumn is an indicator for the amount of cellular respiration and photosynthesis that are occurring. If there is more cellular respiration occurring than your oxygen levels will decrease as organisms use the oxygen and release carbon dioxide. If the oxygen levels increase then the plants are performing enough photosynthesis to outweigh the amount of oxygen being used by the animals and decomposers.
CO2 in the water– the BTB test is another measure of pH. Carbon dioxide is acidic, it lowers the pH of the water. If your organisms are doing a lot of cellular respiration than you would expect the amount of CO2 in the water to increase.