Ground Cover

Objective

In this activity, students will closely map their field site, using a color-coded grid system to indicate different types of soil habitats. They will then calculate the percentage of poor, average, and good quality food sources at their field site and analyze what this means for the critters that live there. Students will practice mapping skills, increase spatial reasoning and estimation, and gain an understanding of the soil environments at their field site.

Making the connection:

  • By doing this activity along with Food Source Habitat, students can gain a better understanding of how the ground cover roots can affect soil organisms.
  • By doing this activity along with Looking for Life and Rock Flip, students can see how micro-habitats relate to the critters they observe.
  • By doing this activity along with Soil Properties, students can see how soil properties relate to food sources and habitats.

Activity

Hypothesize

What soil habitats are in our field site? What percent of our field site contains good quality food sources for soil organisms?

Plan it!

  • If you haven't already done so, choose a field site and map it in your field journal.
    Although students will complete a detailed map of the field site in this activity, it will still be beneficial for complete a general field site map introduced in the field site activity. This will allow them to compare the detailed and general maps. The general map will also be used in other Underground Adventure activities.
  • Review the information about soil habitats provided on the Habitats in Your Backyard information sheet .
    If possible, students should first complete the Food Source Habitat activity to gain a better understanding of the various habitats found in a site.

Do it!

  1. Take a walk around the field site and note generally where the various soil habitats are. On the Map Your Field Site worksheet , quickly sketch any buildings and major topographical features, such as hills or streams.
  2. Walk around the field site a second time. This time, color the squares on the grid according to the soil habitat type, using the color key on the Map Your Field Site worksheet. Take your time and be as accurate as possible.
    Some students may want to sketch out the areas first and then color them in. Note that splitting the grid squares will increase the difficulty of the mathematical portion of this activity. Although some students may finish early, encourage them to go back over the field site.

Record it!

  • When you return to the classroom, count the number of squares for each color and record it on the chart on the Ground Cover worksheet.
  • Complete the math problems on the worksheet using the numbers you collected. This will tell you what portion of your field site is poor, average, and good quality food source habitat.
  • Add the map and worksheets to your field journal.

Remember, be sci-wise!

  • Be a good observer. Noting details of your field site will help you to record the soil habitats accurately.
  • Double-check your work. If you have time, walk over the field site a third time to check your map.
  • You'll need to prepare for the dirt and mud that will be brought back on students' shoes. Consider having students bring in an old pair of sneakers or boots to use for your field activities. Students can leave their dirty shoes "at the door" and then shake or brush them off when the mud has dried.

Assessment and Reflection

  • What kinds of habitats did you find at your field site? What percentage of your site was of good quality for finding food sources?
    Answers will vary.
  • Based on the data you mapped and interpreted, do you think your hypothesis was correct or incorrect?
    Answers will vary.
  • Compare the field site map you created in this activity with the one you created when choosing your field site. How closely do the major features and buildings you recorded match? Which map is more detailed? Which do you think is most accurate? What kind of information does this map have that the other map does not? What kind of information does the other map has that this one does not?
    Answers will vary.
  • Looking at the math calculations you made, can you infer what percentage of your field site is not likely to have a good variety of soil critters?
    Answers should be based on the percentage of the field site with poor food source habitats.
  • Looking at the math calculations you made, can you infer what percentage of your field site is most likely to have healthy earthworms?
    Answers should be based on the percentage of soil with good food source habitats.
  • After mapping the field site in this way, do you still think this site is a good choice for doing field work on soil critters? Why or why not?
    Answers will vary.
  • Based on your research, what actions would you suggest for improving the soil at your field site? How might these actions benefit humans?
    Answers will vary.
  • Complete this section of the Factors That Affect the Soil Overview worksheet .
  • Looking at the big picture, how might the data you mapped and analyzed here help you answer your research question?
    Answers will vary, but students should begin to make connections between the data they recorded here and the data they gathered in other activities.

Extensions

  • Mapping and Measuring
    To make an even more accurate map of the field site, have students measure the area of the site and create a scale to show the ratio between the real space and their map (i.e., one inch = one foot). If possible, allow students to actually grid off the field site and then remap it. You can use flour to create the grid lines—be sure to create fairly large grid squares. Once students have created the map, they can compare it to their earlier maps. Which is more accurate? Why? What other ways can they think of to make the map more accurate? What techniques do cartographers use?
  • Sampling
    Have students take soil samples from different types of soil habitats within your field site. How do they compare? Which areas have greater numbers and diversity of soil life? Why? If you are doing the Looking for Life and Rock Flip activities, you can make these comparisons by having students spread out to various soil environments within the site to do the activities.

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