Fire-scarred ponderosa pine (Pinus ponderosa) stump from south side of the Wet Mountains, Colorado.  This tree is fairly rare in that the scars are completely enclosed in this one area of the stem.  Typically ponderosa pine grows slowly enough that the next fire would have come along and killed the cambium before the woundwood had a chance to regrow over the previous scar.  This tree had another open sequence of scars on a catface to the left of the scar sequence shown in this image.  This tree is reported in the study Brown and Shepperd 2001.

Fire-scarred ponderosa pine (Pinus ponderosa) snag from Mount Rushmore National Memorial, Black Hills, South Dakota.  This tree probably died of a bark beetle attack as evidenced by the presence of blue stain in the little bit of sapwood still present in the upper right.  The presence of sapwood also allowed for dating the death of the tree to 1916.  The pith date on the section was 1474.  This section was given to the Mount Rushmore Memorial for a possible display in the visitor center.

Fire-scarred ponderosa pine (Pinus ponderosa) from Ashenfelder Basin, Laramie Peak, Wyoming.  This tree also likely died from bark beetles as evidenced by blue stain in the sapwood.  Also note the wood-boring beetle larvae tunnels in the sapwood. This tree was part of the study reported by Brown et al. 2000.

A living fire-scarred coast redwood (Sequoia sempervirens) from Jackson State Forest, Mendocino Coast, California. Note the decay associated with the woundwood at the scar margins.  This is very typical on coast redwood. This section and the next two were part of a study reported in Brown and Baxter 2003.

Another living fire-scarred coast redwood (Sequoia sempervirens) from Jackson State Forest, Mendocino Coast, California. Note how the stained heartwood ends at the scar margins within the rings and does not extend into the woundwood. This results in the scars being very susceptible to decay or removal from burning, as you can see in the older scars on this section.  Note also the incredible woundwood response after the last fire in 1934. 

Another living fire-scarred coast redwood (Sequoia sempervirens) from Jackson State Forest, Mendocino Coast, California. Again note how the woundwood is very decayed especially underneath the incredible woundwood response after the last fire scar in 1934.  By the way, on all of these sections the dating is not exact; these are the only trees that I have worked on in which crossdating is not possible because of wedging rings, or a lack of circuit uniformity.  Coast redwood is pretty much impossible to crossdate.  

Living fire-scarred Rocky Mountain bristlecone pine (Pinus aristata) from Packer Gulch, South Park, Colorado. The inside date on this tree was 1120 with an estimated pith date of ~1050.  The tree has heart-rot as you can see from the image, but there were plenty of rings with which to date the section and the fire scars.  There were several trees in the stand up to ~1000 years old, and many were killed in a crown fire in 1978 (suggesting that the 1978 fire was outside the historical range of variability in the stand for at least the past millennium). 

Living fire-scarred piñon pine (Pinus edulis) from Boulder Mountain, Utah. Fire-scarred piñon pine are rare but I doubt that is because surface fire never occurred in these stands.  This tree is a terrific example of that.  It was collected ~30 m from two ponderosa pine trees that recorded both of the scar dates on this tree as well as 4 additional dates during the time this tree was alive.  Fire probably burned in the vicinity of this tree during those other years but did not get hot enough to kill the cambium and form a scar, probably because of more dense fuel bed characteristics in piñon versus ponderosa needle litter.

Living fire-scarred Rocky Mountain juniper (Juniperus scopulorum) from Archuleta Mesa, southwestern Colorado.  I could not crossdate the entire section but was able to date the outer two scars with confidence. Southwestern junipers are very difficult to crossdate because of missing and false rings, and rarely do they have fire scars.  So this was a very unusual tree all the way around. 

This is a white spruce (Picea glauca) section from central Alaska that is ~2Mya.  It was found by the late Troy Péwé in permafrost loess deposits of the Dawson Cut Forest Bed just north of Fairbanks. John Westgate from the University of Toronto is currently finalizing a manuscript describing the history of research and findings from the Dawson Cut Bed. 

Ramzi Touchan of the Laboratory of Tree-Ring Research at the University of Arizona coring a giant sequoia (Sequoiadendron giganteum) just north of Kings Canyon National Park in California.  A 50 cm increment borer is not much of a match for a 3m diameter sequoia! Research that I was involved in the sequoia is reported in Hughes and Brown 1992 and Brown et al. 1992.