(Optional) Activity 3.4: What Happens to Soil Carbon? (30 min)

Target Student Performance

Students explain the role of detritus and detritus-based food chains in ecosystems.

Resources Provided

3.4 Food Webs Video Worksheet (1 per student)
3.4 Grading the Food Webs Video Worksheet

Setup

Prepare one copy of 3.4 Food Webs Video Worksheet for each student. Prepare a computer with a projector to display the video.

Directions

1. Introduce students to the “extensions” in this Activity: a video.

Tell students that in this activity, they will be think about what happens to the carbon that ends up in the soil through death, feces, and defecation.

2. Watch the video.

On a computer with an Internet connection, open the video at this link: https://www.youtube.com/watch?v=KI7u_pcfAQE. Give each student a copy of 3.4 Food Webs Video Worksheet. Instruct students to complete questions 1-7 during the video. Pause the video as the worksheet suggests to give students a chance to complete their worksheet.

After students have completed questions 1-7 on their worksheet, watch the video again.
After they watch the video for the second time, instruct students to answer question 8 on their worksheet.

Accommodation: After the first full viewing of the video, discuss each question before moving on to the next segment of the video and next question.

3. Discuss the video.

Ask students to share their responses from the worksheet with the class. Look to see if they are able to tell a story about why the soil pool (that contains detritus and decomposers) is so important to the food web.

Ask students what will happen to the carbon from the soil after it is eaten by decomposers and animals. Students should recognize that the soil carbon will eventually become CO₂ in the atmosphere through cellular respiration.

Assessment

During this activity, check to see if students are making connections between the cycling of matter between pools they learned in previous activities with the content of the video.

Tips

Watch the video a few times to help students become familiar with the content.