Center for Tree-Ring Science

10/23/2026

There is no doubt that trees record human influences on the environment. This is particularly evident through records of past fires. Thirty plus years of work developing these records has allowed this story to be revealed, not from the perspective of people, but from these very special old trees. There are many unwritten details of environmental history in tree rings and we are still at the tip of the iceberg for what is possible. Thanks to The New Yorker and author, M.R. O’Connor, for expanding the audience for our work!

By studying fire scars in ancient wood, many scientists have become convinced that Indigenous people transformed North America long before Christopher Columbus arrived.

10/05/2026

Recent fieldwork in the Ozarks brought us to stop by the Current River Pinery, a 100,000-acre conservation area dedicated to the restoration of woodland pines. This restoration requires prescribed burning, returning it to a shortleaf pine dominated stand, allowing for sunlight to reach the forest floor encouraging grasses and forbs to flourish among the widely spaced trees. This area burns every 3-5 years and supports countless songbirds, turkeys, bears, deer, elk, reptiles, insects and more. Some of our research is featured here on signs included in the Current River Pinery Tour, which you can see more of it here: https://oakfirescience.com/current-river-pinery-self-guided-tour/

09/28/2026

A brief overview of fire scars from CTRS Senior Research Associate Joe Marschall!

09/23/2026

Bronco appreciation post! Our 1991 Ford Bronco is still (mostly) going strong! It has been climbing over rocks and mountains across the eastern U.S. and has become a fixture of CTRS field research for over 20 years. The classic vehicle was donated by Richard Guyette and has become the unofficial mascot of the Center. Just know it was hard to choose ~only 9~ photos of this beauty.

09/14/2026

Be a citizen scientist! Next time you’re out hiking around and come across old fire-scarred wood (logs, stumps, snags, or living trees), you can document it using our National Fire Scar Survey app on your phone! Follow this link for download instructions https://treerings.missouri.edu/national-fire-scar-survey/ and add to the collection of over 1000 fire-scarred trees from across the U.S., with more than 400 of these remnants already collected and archived for future analysis. Fire scars on dead or living trees provide site-specific, sub-annually precise, incontrovertible evidence of historical fire. However, due to time, climate, and land-use factors, these invaluable natural archives are rapidly disappearing forever! Recent work to improve the Survey was made possible with our partners at the Mark Twain and Talladega National Forests.

09/07/2026

Pitch pine is exceptionally fire-adapted and requires frequent-fire regimes for successful regeneration and long-term perpetuation. Its fire adaptations include thick bark, serotinous cones (in some populations), basal and epicormic resprouting buds, and the ability to survive (and record) multiple fires. The pitch pine stump pictured here contained 27 fire scars, established in 1734 with an outermost ring of 1898! This pine was located in central Pennsylvania where many ecosystems are converting to fire-intolerant communities due to a century of fire suppression. You can read more about it here! https://www.mdpi.com/1999-4907/7/10/224

08/31/2026

Movie day at lab lunch! What did we watch? A great short film about bristlecone pines, the world's oldest living trees, and dendrochronology of course! https://youtu.be/ulxjQ5sIlek?si=sbcRomXtWE76p0Zx

08/24/2026

“Frost rings” are collapsed and damaged (embolized) cells caused by prolonged freezing temperatures during the growing season. This generally occurs in the spring when the cells, or xylem, are saturated and soft, actively transporting water in the tree. Water freezing in the cell causes them to deform, break, and collapse appearing crushed together and causing the darkened appearance (see red arrow). This piece, and several others from this study in central Texas, show a frost ring in Ashe juniper - a great example of tree rings recording a significant historical weather event.

08/17/2026

To closely examine wood specimens, like this Missouri post oak, we typically sand from 80 grit to 1200 grit polishing sandpaper. Fine sanding and polishing produce a pristine and scratch-free surface of the cellular detail needed for accurate measuring, viewing, and analysis, either through the microscope or a high-resolution photograph!

08/10/2026

Look closely enough at this 5’ x 5’ longleaf pine cross section, and you will see it is covered in hundreds of pencil marks! Senior Research Technician, Erin Abadir, dated every inch in every direction, giving annual resolution to every injury this piece holds. Too big to measure with our typical instruments, Erin used a magnifying glass and light while lying on the piece as she went. It was visually cross dated using the marker years, or the extremely narrow rings, aligned with those from chronologies of other pines in the area. With a pith date of 1484 and outer ring of 1884, this longleaf had 57 fire scars, most of which occurred in the growing season. The earliest fire scar was in 1540, and latest scar in 1864. This sample is from southwest Georgia.