Stimulating Understanding of Computational science through Collaboration, Exploration, Experiment, and Discovery for students with Hearing Impairments
a collaboration of the Shodor Education Foundation, Inc., Eastern North Carolina School for the Deaf, Barton College, the National Technical Institute for the Deaf, and Interpreters, Inc.

For Teachers!

How to weigh a tree

Overview:In this lesson students pick a tree they see everyday, perhaps one at school. They measure the tree's circumference and estimate its height using similar triangles. Using that information and the type of tree they calculate the tree's weight and the CO₂ sequestered in the tree. They relate the sequestered CO₂ to the CO₂ produced by their families and the school.  

The material for this lesson is presented two ways. There is a sample lesson which your students can use online. You can also follow the lessons via class discussions. This allows individualization by you and your students. The second approach is a collection of the models and data used in the lesson. You can pick and choose from these tools and other material you find to design your own lesson. 

Depending on the time you can commit to this activity, you can either help the students work through the algorithm used to calculate the carbon in your tree or you can move straight to the completed model. The computational science skills involved in this lesson involve learning how to use computer models and evaluating their output.

A note on the formulas used to calculate the carbon in your tree. I am using formulas derived by foresters to estimate the weight of classes of trees in the forests of the southeastern U.S. Similar studies and formulas are available for trees in different sections of the U.S. and, I assume, the world. These formulas are used extensively by the forestry industry to plan where and when to harvest their forests. The formulas are a best fit for the data and as such more of an estimate rather than an exact value. I contacted my county extension agent to get the formulas. He didn't know the formulas but he forwarded my request to foresters in my state who were eager to help me. Most of the trees in the studies were in stands of trees, not an isolated tree in a grassy field. 

This lesson leads into a second lesson that looks at the "Carbon Sequestration by Forest" over time. This is provided by a professional model, built by a team of Dutch scientists at the Wageningen University and Research Center, Silviculture and Forest Ecology Group. 

I have provided an answer key to my lessons. The student questions are in red and suggested answers are blue. 

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This project is supported, in part, by the National Science Foundation Opinions expressed are those of the authors and not necessarily those of the National Science Foundation.