Disruption in Ecosystems - Matter in Ecosystems 2.3

The Lawrence Hall of Science SEPUP Program American Museum of Natural History
Type Category
Instructional Materials
Lesson/Lesson Plan
This resource, vetted by NSTA curators, is provided to teachers along with suggested modifications to make it more in line with the vision of the NGSS. While not considered to be "fully aligned," the resources and expert recommendations provide teachers with concrete examples and expert guidance using the EQuIP rubric to adapted existing resources. Read more here.



This lesson (Chapter 2 Lesson 3) is part of a unit developed by the American Museum of Natural History, The Lawrence Hall of Science SEPUP Program, and the University of Connecticut. The unit follows the 5E model (Engage, Explore, Explain, Elaborate, and Evaluate) to help engage students in making sense of the movement of matter in an ecosystem. This lesson builds on the students’ food web model from Chapter 1 and expands their existing understanding. The guiding question for this lesson is, “How does matter move between the biotic and abiotic parts of an ecosystem?” First, students fill out the Anticipation Guide to share their initial thinking. Then they use a reading from the Scientific Findings in the student handouts to develop a model to show how matter, specifically carbon dioxide and water, moves between producers, consumers, and decomposers. Students further apply this thinking to describe what happens to matter when fire disrupts the Yellowstone ecosystem. Next, students construct a scientific explanation for where a plant gets the matter it needs to grow. Finally, students again reflect on their new understandings as they return to the Anticipation Guide.

To access the lesson and the unit, teachers need to download the zip file from the Achieve website Quality Examples of Science Lessons and Units.  

Intended Audience

Educator and learner
Educational Level
  • Middle School
Access Restrictions

Free access - The right to view and/or download material without financial, registration, or excessive advertising barriers.

Performance Expectations

MS-LS2-3 Develop a model to describe the cycling of matter and flow of energy among living and nonliving parts of an ecosystem.

Clarification Statement: Emphasis is on describing the conservation of matter and flow of energy into and out of various ecosystems, and on defining the boundaries of the system.

Assessment Boundary: Assessment does not include the use of chemical reactions to describe the processes.

This resource is explicitly designed to build towards this performance expectation.

Comments about Including the Performance Expectation
The activities in this lesson focus on the cycling of matter by tracking the movement of carbon dioxide and water molecules among producers, consumers, and decomposers. Students also examine a compost bag during the Scientific Findings to understand how decomposers break down dead organisms and transfer matter to the abiotic part of the ecosystem (soil and air). Students further apply this concept to a forest ecosystem when it experiences changes as a result of fire. Energy flow is addressed in some statements on the Anticipation Guide, but there are not many activities in this lesson that help students develop this understanding. The following lesson (Lesson 2.4) is where students go more in depth into the source of energy and the direction of energy flow in ecosystems.

Science and Engineering Practices

This resource is explicitly designed to build towards this science and engineering practice.

Comments about Including the Science and Engineering Practice
Students obtain information about matter in ecosystems by reading the Scientific Findings. Students revise the Yellowstone food web they developed in the previous lesson by adding blue arrows to represent the movement of matter. The process of constructing the model helps students make sense of how matter moves through the different levels of the food web. Students also annotate the model with evidence from the Scientific Findings. As students share their ideas with the class, this is a good opportunity for students to peer review each other’s models and reach class consensus.

Disciplinary Core Ideas

This resource is explicitly designed to build towards this disciplinary core idea.

Comments about Including the Disciplinary Core Idea
The Scientific Findings provide background information that students use to develop understanding toward this DCI. The Explanation Tool helps students construct a scientific explanation on how plants get the matter they need to grow. Additional learning activities should be provided to help students understand the difference between molecules and atoms (such as Build a Molecules by Phet https://phet.colorado.edu/en/simulation/build-a-molecule) and how atoms are rearranged through chemical reactions (such as Photosynthesis by Edgerton Center at MIT https://edgerton.mit.edu/node/120). Video clips such as “Flow of Energy and Matter through Ecosystems” by Khan Academy (https://www.khanacademy.org/science/high-school-biology/hs-ecology/trophic-levels/v/flow-of-energy-and-matter-through-ecosystems) also provides a good overview of this concept. Hands-on investigations for photosynthesis and cellular respirations are strongly recommended to deepen this understanding. One example is investigating photosynthesis with elodea (https://ngss.nsta.org/Resource.aspx?ResourceID=170).

Crosscutting Concepts

This resource is explicitly designed to build towards this crosscutting concept.

Comments about Including the Crosscutting Concept
Students identify the inputs and outputs of photosynthesis, cellular respiration, and combustion through the Scientific Findings. Students at the middle school level would benefit greatly from concrete examples, such as using physical molecular models to see how atoms are rearranged in different reactions and thus cycle through the system. These hands-on activities can be incorporated into this learning segment after the students read about the Scientific Findings.

Resource Quality

  • Alignment to the Dimensions of the NGSS: This is a three-dimensional lesson in which students use a model to make sense of how matter cycles through ecosystems. Students support the model with scientific evidence and use the model to construct a scientific explanation. Although a guiding question is provided in the lesson, it is not clear what the investigative phenomenon is and how students’ questions are used to motivate the sense making process. The decomposition bag that students observe during the Scientific Findings can be introduced at the beginning of the lesson. It is an interesting phenomenon that can prompt students to ask questions about where matter comes from and how it moves through different organisms.

  • Instructional Supports: Many instructional tips are provided throughout the teacher guide to help support students as they develop their scientific model. For example, tips to scaffold each finding are included. Teachers are also encouraged to first demonstrate how to incorporate 1-2 findings into the group model if needed. Strategies for Language Learners are also provided, including sentence starters to help students reflect on their learning and sample captions. To make the learning more meaningful and relevant for the students, consider applying this to a local ecosystem that contains plants and animals with which the students are familiar.

  • Monitoring Student Progress: In this lesson students fill out an “Anticipation Guide” to elicit their thinking before and after the activity. Teachers also monitor changes students make to their consensus models to assess their growing understanding. Assessment checkpoints are embedded throughout the Teacher Guide with standards alignment. This helps teachers identify formative assessments and intervention opportunities. Sample student responses are also provided for the Explanation Tool.

  • Quality of Technological Interactivity: - none -