Terrarium Lab
Objective/Introduction:
The objective is to make a terrarium to observe the ecosystem inside; and to observe the cycles of energy and matter.
Hypothesis/ Specific Question:
I predict that the black ants will eat the compost and then the crickets will eat the ants as a secondary consumer.
Materials:
Glass Bowl
Gravel
Earthworms
Crickets
Black Ants
Charcoal
Soil
Decomposing plants
Small Flowers
Moss
Pebbles for decoration
Methods/Procedure:
Step 1: Put the soil, gravel, and charcoal in and plant the plants.
Step 2: Add the ants
Step 3: Add the crickets
Step 4: Add the worms
Step 5: Add the spider
Step 6: Observe
Analysis:
Some of the factors, both biotic and abiotic, that have limited our terrarium would be the fertility of the soil, an inconsistent watering pattern, the physical space inside the dimensions of our terrarium, how fast the leaves could decay, and the supply of food to the organisms in our terrarium. For example, the space that our container provides limits the carrying capacity of our terrarium. Also, the amount of food that was provided limits the biodiversity as well as carrying capacity of our terrarium because it is a limited source and so cannot support many types of organisms.
The plants photosynthesize and the carbon in the atmosphere is mixed with water to make sugars. The plants also release carbon dioxide back into the atmosphere as a form of respiration. There are also dead leaves in our terrarium. The carbon inside the dead plants would soon be mixed into the soil. The decomposers which are the earthworms release carbon when the decompose the dead leaves.
There is nitrogen in the air. Bacteria help the nitrogen that is absorbed into the soil change between states so that it can be used the plants. Fixation is the first step in making nitrogen usable by our plants. Bacteria help it change into ammonium. The next step is nitrification. The ammonium is then changed into nitrates by the bacteria. Then the plants absorb the nitrates which get used in amino acids, nucleic acids, and chlorophyll. When our plant died it went through a decaying process called ammonification. The earthworms and bacteria turn the nitrogen back into ammonium. Extra nitrogen in the soil get put back into the atmosphere which is called dentrification.
Results:
Day 0: We filled our terrarium with soil/pebbles/moss/small plants/decomposing leaves/charcoal. No live animals yet.
Day 3: The plant seems to be dying
Day 6: Plant still dying - animals are doing fine
Day 9: Animals have not died. We have a new life! A small plant sprout has appeared.
Day 13: Original plants are dead. Plant sprout has been joined by its brethren.
Day 15: Whoo our two plants sprouts are growing up fast. Everything else is dead.