This is a competition activity for the children while they learn about ecosystem. The purpose of this "Mini Ecosystem" activity is to show complex relation between biotic and abiotic factors in a small scale ecosystem. When "Mini Ecosystem" become stable from the beginning until the end of experiment, we may give children good score. Don't forget to ask the process and their argumentation, not only for the results, so the score will be given according : final results and argumentations
Some glass jars / small aquariums, plastic wraps, rubbers, some small water snails
First divide children into groups. They will have one glass jar (or a small aquarium) to decorate. Fill the jar with water.
You may help them in general, explain about relation between biotic and abiotic factors in ecosystem,
1. Give two days to the groups to let them decide what things are better to make a stable ecosystem.
2. Let them decide the water source for the experiments
Hints: a group that use water from a pond will get good score - because it rich with organic and anorganic matter (also it consist more phytoplankton, zooplankton, bacteria,..). A clear water will get only normal score.
Fill the jar with a snail and then other biotic and abiotic things (they choose themselves). Close the jar with plastic wrap. They may choose a place to put their experiments (they will decide direct sunlight intensity for their experiments). After picking places, they are not allowed to move the place, open the plastic wrap until it finish (day 14).
They may look their experiments. Are they make a stable mini ecosystem in their jar?
Question to discuss (just for an example):
- IS the snail still alive - why?
- Do you put plant in the water - why?
- Explain the relation between biotic and abiotic factors in this experiment
- Are we created a stable ecosystem from the beginning?
- Are the ecosystem reach stable condition in the end of the experiment? Why you say that?
- What is the meaning of a stable condition for an ecosystem?
There are no just "yes or no" answer. The best answer is if the children can explain the condition according scientific answer. Not to be forgotten, you also can add one more experiment, to show the children about pollution effect: add one experiment with pollution matter like detergent or oil... the result will be shown later and then, we also can discuss about water pollution.