Lesson Overview: Students study the scars left by low-severity fires on tree trunks-how the se scars form, how many have marked a tree, and how many years went by between fires. With this information, they can describe the history of low-severity fire for that tree. With data from the whole class, they can describe the history of low-severity fire for a whole stand or forest. Finally, they can compare their results with those of two research studies and two efforts to summarize information on the history of low-severity fire in California.

Lesson Goals: Students understand that some trees can survive frequent low-severity fire. They can describe the history of low-severity fire for a specific tree, a stand or forest, and (based on results from the literature) an entire kind of ecosystem, California mixed-conifer forests.

Objectives:

• Students can identify tree growth rings and fire scars.
• Students can describe the history of low-severity fire for a single tree.
• Based on pooled data, students can make inferences about the history of low-severity fire in a specific forest.
• Students can compare and contrast their results with those from sources in the scientificliterature.