Teaching Notes

Example Output

Model created by isee Player. Click image for a larger view.

This image displays a graphical representation and tabular data created by running the isee Player. The model was created by running data specific to New Hampshire's forests through the Player and provides insight to the role that forests play in the carbon cycle.

Grade Level

This activity is appropriate for grades 9-12.

Learning Goals

After completing this chapter, students will be able to:

  • understand the role forests play in the carbon cycle and climate change;
  • run a basic computer model by changing input values;
  • describe the value and limitations of using models in the field of science; and
  • explain how model output and field data are both important for understanding natural systems.


This chapter provides an interesting and relevant example of how basic models can be used in the classroom to understand scientific concepts. The activity allows students to compare collected forest data to model output and evaluate the results of that comparison, which is often done in research science. Finally, the lesson's questions are designed specifically to increase students' understanding of modeling concepts such as systems in equilibrium, as well the proper use and limitations of models.

Background Information

Basic information about the carbon cycle, climate change, forests, and modeling written for teachers by the GLOBE Carbon Cycle team is available at the GLOBE Carbon Cycle website.

Some additional scientific articles that may be of interest are listed below. Keep in mind these articles range in depth and difficulty. Please keep the age and ability of your students in mind when assigning reading.

General Forest Ecosystems
Ollinger, S. (2002). Forest Ecosystems. Encyclopedia of Life Science-Nature Publishing Group. 1-10.
Doyle, R. (1996, November). By the Numbers: Global Forest Cover. Scientific American Magazine, 275, 32.

Forests, Carbon and Climate
Bonan, G. (2008, June 13). Forests and Climate Change: Forcings, Feedbacks and the Climate Benefits of Forests. Science, 302, 1444-1449.
Angelo, C. (2005, February). Punctuated Disequilibrium. Scientific American Magazine, 292, 22-23.
Simpson, S. (2001, February). Debit or Credit? Scientific American Magazine, 284, 25.

Key Terms and Prerequisite Knowledge

Students should have at least a basic understanding of biomass and carbon storage in trees (i.e., trees photosynthesize, take in carbon dioxide from the air, and store it in their cells). Students should also know that nitrogen is a common element found in the air and the biosphere.

It would be extremely helpful to students, although not completely necessary, if they have had some experience with modeling concepts such as: stock/pool, flow/flux, steady state/equilibrium.

Students should be familiar with Microsoft Excel's cut, paste and equation functions.

Instructional Strategies

Begin by engaging students in the essential question:
  • What do forests have to do with climate change?

Elicit student's prior knowledge about climate change through a class discussion and record their thoughts on the board. You may need to ask some probing questions such as:

  • What are some of the major factors/contributors to climate change?
  • Can you think of any links between forests and climate?
  • Can you name any elements/compounds that are involved in climate change?

Tell students that scientists have multiple methods for studying carbon storage in forests, which include field data collection and computer modeling.

Let students begin by reading some information about forests and their role in climate. For references, see the suggestions in the background section (above) and Part 1: Developing a Forest Model.

You should now make sure that the Excel FIA data file, the Excel template file, ISEE Player application and the Biomass Accumulation Model file (to be opened using the ISEE Player) are loaded onto student computers. This is Part 2 of the chapter.

Students are now ready to begin Part 3: Exploring Carbon in New Hampshire's Forests. First, students will open the forest data and explore the data tables by answering basic questions. Have students continue to work through the New Hampshire example from the FIA forest data, to filling in the template, and on to running the Biomass Accumulation Model. If you have students work in pairs, make sure each student has an opportunity to run the model and is able to read the output graphs and tables. Checking the numeric results of the New Hampshire example will ensure that the students know how to fill in the Excel template and use numbers from it to run the model.

Be sure to allow plenty of time for students to answer the follow-up questions. Questions are meant to be challenging and many of them do not have precise answers. Encourage students to think carefully and share ideas.

You may want to briefly discuss with the class implications of the New Hampshire results, but students will likely be much more interested in the model results and comparisons for their own state. You may want to have a follow up class discussion to allow more idea sharing. A good assessment might be for each student group to come up with a forest management plan for their state that would increase/stabilize carbon uptake without being overly detrimental to other local economic or environmental factors, such as agriculture, housing development, or the natural forest ecosystem.

Learning Contexts

The GLOBE Carbon Cycle team strongly suggests that you introduce your students to the concept of modeling (basic terms such as stock, flow, and equilibrium will be important) before doing this activity. There are many different ways to introduce these concepts. One way is through a hands-on classroom activity called the Paper Clip Factory at the GLOBE Carbon Cycle website http://globecarboncycle.unh.edu. For other introductions as well as more advanced ideas about modeling and the nature of systems check out the Creative Learning Exchange http://www.clexchange.org and the Waters Foundation http://www.watersfoundation.org/.

For additional science content, and details about the model's equations, you can have students walk through the storyline built into the Biomass Accumulation Model. Enter the storyline by clicking "Read About this Model." Accompanying questions are found in the document Biomass Accumulation Model Introduction which may be downloaded from Resources at the bottom of this page.

Lastly, to become more familiar with the model basics (i.e., how to read the graphs and tables, how to change individual variables) and to investigate how you might use models to study effects of modifying individual variables, students can run the model to answer basic questions in Biomass Accumulation Model Activities in Resources at the bottom of this page.

Science Standards

The following National Science Education Standards are supported by this chapter:

Grades 5-8
  • 8ASI1.3 Use appropriate tools and techniques to gather, analyze, and interpret data.
  • 8DESS1.11 Living organisms have played many roles in the Earth system, including affecting the composition of the atmosphere.
  • 8EST2.3 Science and technology are reciprocal. Science helps drive technology, as it addresses questions that demand more sophisticated instruments. Technology provides the instruments and tools for observation and investigation.
  • 8GHNS2.1 Scientists formulate and test their explanations of nature using observation, experiments, and theoretical and mathematical models.
Grades 9-12
  • 12ASI1.1 Identify questions that can be answered through scientific investigations
  • 12ASI1.2 Design and conduct a scientific investigation
  • 12ASI1.3 Use technology and mathematics to improve investigations and communications.
  • 12CLS4.1 The atoms and molecules on the earth cycle among living and non-living components of the biosphere.

Math Standards

Grades 6-8
  • Use mathematical models to represent and understand quantitative relationships
  • Model and solve contextualized problems using various representations, such as graphs, tables, and equations
  • Analyze change in various contexts
  • Use graphs to analyze the nature of changes in quantities in linear relationships

Grades 9-12


  • Use mathematical models to represent and understand quantitative relationships
  • Draw reasonable conclusions about a situation being modeled
  • Analyze change in various contexts
  • Approximate and interpret rates of change from graphical and numerical data

Technology Standards

Grades K-12
  • Students use technology tools to enhance learning, increase productivity, and promote creativity.

Time Required

Class Discussion: 20 min
Part 1: 10 - 60 min (depending on selection of additional reading materials)
Part 2: 15 minutes
Part 3: 45 - 60 minutes
Part 4: 45 - 60 minutes
Part 5: 45 - 60 minutes
Questions and Wrap Up: 60 minutes

Some specific questions asked within the Step-by-Step section appear in documents here. There is also an Excel file with just the FIA information for NH filled inallowing you to have your students begin with making the model run and another Excel file of the completed spread sheet for New Hampshire, to check your own work. Lastly, there is a PowerPoint demonstrating the use of the Biomass Accumulation Model with instructions for how to read the results and use all the buttons.