Fire-Scarred Trees

Laboratory
of
Tree-Ring Research

Southwest Fire:

Fire-Scarred Trees

Close up of fire scars recorded in tree growth. Photo by Tom Swetnam

In the past, fires often burned with low intensity
Miller, C. 2010. Review of "Light Burning Versus Forest Management in Northern California." Journal of Forestry 108(1):45-46: This 2010 Journal of Forestry article describes wildland fire back in the early 1900s.
Wounded trees, didn't kill them
Those fire wounds can be dated to the year
Surviving trees are a legacies of past fire occurrence

Ponderosa pine showing many fire-scars in a large catface. Photo by Henri Grissino-Mayer.

These fire scars are dated to the exact years of the fires that made them by a process called crossdating:
- Matching patterns of wide versus narrow rings across many tree samples
- Often done by skeleton plotting the ring growth onto graph paper

Cross section showing many fire-scars (white arrows). Photo by Chris Baisan.

Try skeleton plotting for yourself on the Internet
- Graphically represent ring-growth variation
- Match sample marks with those from a master chronology

Example crossdating of sample graph (top) with master graph (bottom). Image by Paul Sheppard.

Tree-ring fire sites of the Southwest often have several multiple-scarred trees

Example fire graph for Bandelier National Monument, New Mexico. Image by Tom Swetnam.

Southwest Fire Home

Laboratory of Tree-Ring Research, University of Arizona
Tucson, Arizona 85721 USA
Main Office: (520) 621-1608, Fax: (520) 621-8229
Comments to Paul Sheppard: sheppard @ ltrr.arizona.edu

LaboratoryofTree-Ring Research

Southwest Fire:Fire-Scarred Trees

Laboratory
of
Tree-Ring Research

Southwest Fire:

Fire-Scarred Trees