Looking for Life

What We're Doing

In this activity, you will look for, identify, and count the organisms found in soil samples from your field site.

Why We're Doing It

A great diversity of life exists underground. By collecting and observing soil samples over a period of time, you can learn about the types and numbers of organisms living there.

Making the connection:

Getting Our Hands Dirty

Hypothesize

What types of creatures live in the soil at your field site and how many of them are there?

Plan it!

  • If you haven't already done so, choose a field site and map it in your field journal.
  • Decide how often to collect soil samples. If you are working with a group or as a class, you should decide together. As you decide, think about these questions:
    • How might your results be affected if you collect daily samples?
    • How might your results be affected if you collect monthly samples?
    • How might your results be affected if you collect annual samples?
  • Before you get started, review the Underground Adventure Field Guide to become familiar with the organisms listed there. Print out a copy of the field guide to take with you into the field. You can also prepare by doing the Critter Quiz online activity.
  • Once you are at the field site, each student or group of students should set up a quadrant in which to work.

Do it!

  1. Within your quadrant, dig a small hole with a trowel or spoon to a depth of about 2 inches. If you have difficulty estimating the depth, you can use a plastic ruler to check your estimate.
  2. Place the soil from the hole onto a white paper plate to get a better look.
  3. Search through the soil for organisms. Use a magnifying glass to get a closer look at the organisms in your soil sample.

Record it!

  • Record the characteristics of each different organism you see on the Looking for Life worksheet .
  • Count each different type of organism and record this number on your worksheet.
  • Use the Underground Adventure Field Guide to identify each organism. Record your identification on the data sheet.
  • In your field journal, draw the organisms you find in the soil sample.
  • Add the worksheet to your field journal.

Remember, be sci-wise!

  • If the ground is too hard to dig in, try moving to a nearby spot.
  • Be careful while digging with a trowel. The edges are sharp.
  • Handle the magnifying glass carefully to prevent it from breaking.
  • Even if you think you know what an organism is, it is a good idea to double check with the Underground Adventure Field Guide .
  • Handle all insects gently and respectfully. Return the organisms and soil to the ground when you have finished.
  • Be sure to clean and properly store all equipment.

Thinking About It

  • Did you find the creatures you expected to find in the soil sample?
  • Based on the data you collected, do you think your hypothesis was correct or incorrect? Why?
  • How did the creatures compare to their descriptions in the Underground Adventure Field Guide ? Did they look the way you expected them to?
  • How might the depth of the soil sample affect the types of creatures found there? What data could you collect to test this?
  • What effect might moisture have on the types and numbers of creatures in the soil? What data could you collect to test this?
  • What relationship did you notice between the creatures found in the soil and the air and soil temperature?
  • What would you expect to observe in your soil sample if you used a microscope?
  • If you were to continue collecting soil samples for a whole year, what differences would you expect to find?
  • How do the types of creatures found in the soil affect the soil? How do they affect plants? Animals? People?
  • How does the data you collected here differ from the data you collected in Rock Flip? Why might this data be different? What data could you collect to try to prove your hypothesis?
  • Complete this section in the Soil Biodiversity Overview worksheet .
  • Looking at the bigger picture, how might the data you collected here help you to answer your research question?

Still Interested?

If you liked this activity, try these:

  • A Day in the Life
    Choose one of the critters you saw in your soil sample and write a story about it. Imagine "a day in the life of" this critter. Where would it go? What would it do? Use the Underground Adventure Field Guide to find information about the critter to help you write the story.
  • Sampling
    You can't count all the critters at your field site. Instead you, like all scientists, counted only a sample. How could you use math to estimate how many critters there are at your site?
    1. Find the area of your quadrant (the length multiplied by the width).
    2. Figure out how many quadrants there are in your site (the total area of your field site divided by the area of a quadrant).
    3. Multiply the number of each creature you found by the number of quadrants in your site to estimate the number that would be present in the entire field site (5 ants multiplied by 400 quadrants equals 2,000 ants).

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