Explore: Soils are a complex 3-D Habitat

Educators may want to build a vocabulary wall as students are working through these labs. To save time and materials these labs can be set up as stations and students can rotate through them in a period of days.

Part A: Soils are Living: From Pedon to Pore

Complete the Soils are Living, from Pedon to Pore activity.
Description: In this activity, participants dig up a sample of soil (or pedonA three-dimensional body of soil with lateral dimensions large enough to permit the study of horizon shapes and relations. Its area ranges from 1 to 10 m2.) and examine it for life forms within the soil. Educator background and discussion questions are included in the activity. This activity can be completed either outdoors or indoors.
Key point: Soil is a complex habitat consisting of mineral and organic particles; living organisms including plant roots, microbes, and larger animals; and pore spaces filled with air and/or water. 
Time required: 30 -60 minutes

Follow this introduction to life within the soil with the question: "How do fallen tree leaves affect soil?"

Part B: Don't lose your cool: Fallen Leaves Insulate Soil

Complete the hands-on activity Don't lose your cool. 
Description: Students investigate the influence of fallen leaves on the temperature in soil. When soils get too hot or too cold or the soil temperature fluctuates too rapidly, the activity of the living organisms in the soil changes, which can negatively affect the health of the soil and the survival of plants. 
Discussion questions are included in activity.

Key point: Soil temperature plays an important role in many processes that take place in the soil. 
Time required: 45 minutes to make measurements. Additional time is needed to graph and analyze the data.

Part C: The Berlese Funnel

Description: In this segment of the lesson, students use a Berlese funnel and/or microscope to explore soil life. This activity uses a heat source (in this case a light bulb) to dry the sample, forcing the insects through a screen (optional) and into a jar of preserving fluid. Discussion questions are included in activity.

The Berlese Funnel 
Key point: Soil organisms are incredibly diverse, in part because of the many different ways they can obtain energy. 
Time required: 1 class to set up, 1 class to observe insect life in the soil sample.

Part D: Soils Under a Microscope

Watch as Dr. Terry Tollefson uses a microscope to show some of the life in soil.
Description: Students explore samples of soil under a microscope. The Soils under a Microscope factsheet describes some of the features of the soil habitat and the types of life forms one can expect to see at various levels of magnification. 
Time required: 30 minutes 

Note: For educators without access to a microscope, this linked video is a good alternative. It can also serve as an introduction. Watch as Dr. Terry Tollefson uses a microscope to show some of the life in soil. 

Discussion questions to use with activity or video.

  1. What does the soil look like as a habitat?
  2. What types of organisms could you observe?
  3. Did you observe any motile (moving) organisms? If so, describe how they were moving. How do you think this movement helps them in their environment?