People and Planet - The Ecosystem Experiment!

The Earth is made up of 4 main spheres: the biosphere (all living/once living things on Earth) the geosphere (all the rocks on Earth) the atmosphere (all the air on the Earth) and the hydrosphere (all the water on the Earth). These spheres interact with each other as energy and matter cycle through them. These interactions give rise to the processes that shape our Earth.

Earth’s systems (all the things that make the earth work) are dynamic and continually react to natural and human-caused changes. In the following sections you will see examples of this in both the natural world and humans’ influence on Earth.

Photo courtesy Evan Whitaker

In this photo from Mammoth Hot Springs at Yellowstone National Park we see an ecosystem where hot water provides the environment for certain microorganisms to grow. These organisms, in turn, capture calcium and other elements from the environment and create stony mounds which change the path of water flow. Working together, these abiotic and biotic factors create a unique and constantly changing ecosystem.

Your challenge in this activity will be to plan and conduct an experiment to investigate what happens to a small ecosystem when you change one abiotic or biotic factor. Examples of water ecosystems are shown below.


  • Two identical containers (jars, bottles or other containers)
  • Abiotic components
    • sticks
    • stones
    • sand
    • soil
    • water
    • other materials
  • Biotic components (organisms)
    • plants
    • pond water organisms
    • worms
    • snails
    • insects
    • small fish
    • other small organisms
    • Please don't use amphibians, reptiles or mammals in your ecosystems for this experiment.
  • Other supplies or equipment to meet the needs of your plan


  1. Take time to design an ecosystem.
    • This might be as simple as a jar of pond water or as complex as a woodland terrarium.
    • Choose what interests you and what you have the resources to do.
    • Share your design with your teacher or parent before you begin.
    • (Hint: If you are struggling for ideas, search the Internet with the words "Bottle Biology." You will likely find many great ideas for building simple, cheap ecosystems.)
  2. Create two identical ecosystems. Make everything as similar as you can.
  3. Now choose one abiotic or biotic factor that you can easily change. Abiotic factors might include things like temperature, water, light, or the addition of a little fertilizer to one ecosystem. Biotic factors might include things like adding grass seed, extra snails, more fish or organic matter to one ecosystem.
    • Make the single abiotic or biotic change to only one of your ecosystems.
  4. Record detailed observations daily for seven days. Identify any changes and differences you see in each of the ecosystems. You might need to use a magnifying glass or microscope to see some changes. You may need to request equipment from a teacher for measuring abiotic factors like pH, dissolved oxygen, dissolved carbon dioxide or humidity.
  5. Prepare a written report with your observations, data and any graphs or pictures you might have drawn or taken. Make sure to record your thoughts and evidence regarding the effect of the abiotic or biotic change you made to one of the ecosystems.
  6. Share your report with your teacher, a parent or guardian, and/or classmates.