Carbon Sequestration in Campus Trees
In this Spreadsheets Across the Curriculum module, students will build a spreadsheet to calculate the net carbon sequestration in a set of trees using an allometric approach based upon parameters measured on the individual trees. Students determine the species of trees in the set, measure diameter at breast height (dbh), and, from the allometric relationships determined by forestry researchers, use the spreadsheet to calculate carbon content of the tree. Students can then compare their data to that measured a year earlier on the same set of trees, to determine the rate of carbon sequestration.
In this module, students will
- Use Excel to model the amount of carbon stored in a tree.
- Compare amounts of carbon stored by tree species,and by diameter of tree.
- Compare the diameters of trees from one year to the diameters of the same trees a year earlier, in order to compute the rate of carbon storage.
- Develop Excel skills including entering equations, filling cells, and interpreting the results of computations.
- Develop a sense of how allometric relationships are used to help calculate biomass in the biological sciences.
- Develop an understanding of how the power function is related to linear plots on log-log graphs.
- Be able to begin to compare the magnitude of carbon storage in trees to carbon dioxide produced by human activities.
Context for Use
Description and Teaching Materials
This module is a PowerPoint presentation with embedded spreadsheets. Students work though the presentation, answering questions and developing the spreadsheet. If the embedded spreadsheets are not visible, save the PowerPoint file to a disk and open it from there.
This PowerPoint file is the student version of the module. An instructor version is available by request. The instructor version includes the completed spreadsheet. Send your request to Len Vacher (email@example.com) by filling out and submitting the Instructor Module Request Form.
Teaching Notes and Tips
References and Resources
The primary resource for this module is the Biopak software, available from the U.S. Forest Service and the H. J. Andrews Exeprimental Forest (operated jointly by Oregon State University and the U.S. For3est Service). The software is also available on the Web, here, with registration (accessed for the module on August 14, 2007).
This software consists of a DOS program (!) that can probe a database for relevant parameters about a variety of species of trees. The author of this module (Cole) has found it most useful to bypass the DOS program, and import the database from Biopak directly into a spreadsheet.
Another excellent article that addresses differences between amount of carbon stored in trees, and the rate of carbon storage (amounts versus rates)is: "Effects on Carbon Storage of Conversion of Old-Growth Forests to Young Forests," by Mark E. Harmon, William K. Ferrell, and Jerry F. Franklin, in Science, Vol. 247, No. 4943, (Feb. 9, 1990), pp. 699-702.
An excellent textbook dealing with nutrient cycles in forests, and providing excellent background for the processes of carbon uptake in forests is: Principles of Terrestrial Ecosystem Ecology by F.Sturart Chapin III, Pamaela A. Matson, and Harold A. Mooney, 2002, Springer Science+Business Media, Inc. ISBN 0-387-95443-0