Objective Our objective in this laboratory was to model and observe a miniature ecosystem. Hypothesis We believe that our terrarium will survive through winter and become self-sustaining. We also hypothesize that our ants will survive and create a tiny colony and thrive. Materials Glass Jar Dirt Charcoal Gravel Sand Grass Ants Water Procedure We brainstormed practical ideas to make our terrarium. We then decided that a glass jar with dirt, charcoal, gravel, grass, and ants would best suit our needs. First we put in a gravel layer, and then a charcoal layer. The charcoal layer is meant to filter the water. We then proceeded to put in dirt and plant our grass. Finally, we found ants outside and placed them inside our terrarium. Updates The ants in the terrarium have moved into a colony in the side of the jar. They have stockpiled the eggs and seem to be busy in the corner. The grass is doing well, and things seem to be going well. My biggest concern is that the terrarium is not going to receive enough water. Most of the ants in our terrarium are dead, but there are still a few roaming around. Mikey and I believe that the ants are dying because their life span is very short and they cannot reproduce without a queen. Most of the ants in our terrarium are dead, but there are still a few roaming around. Ryan and I believe that the ants are dying because their life span is very short and they cannot reproduce without a queen. The grass is still green, which is a good sign that the soil contains enough nutrients. Our ants seem to have finally died. It is possible that they went deep underground and we can't see them, but I would guess that they died due to their inability to reproduce. The grass has started to get a little yellow, but that is likely because we could not water it while at the Lawrence Hall of Science. Analysis Our terrarium had biotic and abiotic limiting factors. The main biotic factors in our terrarium are the ants and the grass. The ants ate some of the grass and added nutrients to the soil. In turn, the grass served as food for the grass. The important abiotic factors in our terrarium are the sunlight, temperature, soil, and water. The sunlight and the temperature must be stable enough to keep the grass and the ants healthy. We put the terrarium close to the window to allow it to get maximum sunlight and consistent heat. We also watered it four or five days a week to ensure that the grass and ants had enough water to survive, but we also made sure not to drown the organisms. Many nutrient cycles also took place in our terrarium. One cycle that occurred in our terrarium was the carbon cycle. First, the grass used photosynthesis to absorb energy from the sun. Then, the grass produced oxygen that the ants use in respiration, and they added some oxygen to the atmosphere of the classroom. The grass also produces glucose, that when the other organisms eat, gain that energy. Next, the ants and the grasses die, transferring the energy to the living ants. This cycle continues as long as the ants can reproduce. Another cycle was the water cycle. When we watered the environment, water would slowly evaporate over the until we watered it the next time. This made it so that the water did not evaporate all at once. Instead, the water would slowly evaporate back into the soil and out the top. Also, when the plants absorb the water, they expel the water using transpiration. The final cycle that occurs in our terrarium is the nitrogen cycle. When the grasses absorb nitrogen from the atmosphere, they expel ammonia. In a process known as nitrogen fixation, bacteria convert ammonia to nitrates . The ammonia disappears and nitrates thrive, which produce proteins. Finally, proteins add nitrogen to the atmosphere. |