Laboratory of Tree-Ring Research to Debut New Home to Community
The UA’s Laboratory of Tree-Ring Research invites the public to learn more about tree-ring science by visiting the lab’s new building on March 2.

College of Science
Feb. 26, 2013


Bryant Bannister Tree-Ring Building
Bryant Bannister Tree-Ring Building (Photo © Daniel Griffin)

After 75 years in "temporary quarters" under the west side of the University of Arizona's football stadium, the world's first laboratory dedicated to tree-ring research now has a new home.

To celebrate, the UA Laboratory of Tree-Ring Research is hosting a 75th anniversary celebration and public open house at its new building on March 2 from 10 a.m. to 4 p.m.

The Bryant Bannister Tree-Ring Building provides 17,300 square feet of usable space – about 7,000 square feet more than the space the UA Laboratory of Tree-Ring Research was using in the stadium. The building, completed in December 2012, is named for the laboratory's director emeritus.

"Our open house this coming Saturday is our first opportunity to share the new building with the public," said Thomas W. Swetnam, laboratory director and Regents' Professor of Dendrochronology. "One of the most exciting aspects of the beautiful new building is that it is designed, in part, to share our past discoveries and current scientific work with the public.

"Tree rings are a terrific way to learn about time, history and our world. From tree rings we learn about great natural and cultural events, such as droughts, forest fires, volcanic eruptions and the rise and fall of civilizations. You can actually see and touch centuries and millennia of history, all exactly ordered in the sequences of rings."

The study of the annual rings of trees, known as dendrochronology, was invented by Andrew E. Douglass more than a century ago. Douglass, who came to the UA in 1906, pioneered the use of tree rings to date the ancient ruins of cliff dwellings, including those at Chaco Culture National Historical Park and Mesa Verde National Park.

On the ground level, the building's exhibit hall showcases the 2-ton, 10-foot-diameter cross-section of a giant sequoia given to laboratory founder Douglass in the 1930s by the superintendent of Sequoia National Park. The ground floor also has public exhibit space and a multipurpose room that serves as an auditorium and as a teaching lab.

The building's upper floors are wider than the floor beneath, thus giving the idea of a tree canopy that provides shade to the ground below. The open arrangement of the laboratory and office spaces on those floors encourages interaction and collaboration among the lab's faculty and students.

The open house from 10 a.m. to 4 p.m. on March 2 will feature guided tours of the new building, exhibits about tree-ring science and hands-on activities for children.

In addition to the giant sequoia slab, the open house exhibits will include a specimen of the world's oldest known tree and artifacts from ancient southwest archaeology sites.

Researchers will give tours of their labs, discuss the variety of events recorded in tree rings and show visitors how dendrochronologists extract that information from trees.

Scientists will demonstrate how to core a tree to study the timeline captured by the tree's annual rings. Taking such a core does not hurt the tree. Visitors will be able to try their hands at taking a core and will be able to take that core home with them.

"We expect our new exhibit hall will host thousands of visitors each year, and we plan to develop a regular program of tours through parts of our new laboratory spaces, and eventually the archives of our collections as well," Swetnam said.

"To do this we need help, so we are organizing a volunteer docent program."

Docents will lead tours of the building, share the lab's rich history with the public and provide short demonstrations. The training sessions, limited to 30 people, are free. The first one is April 6, from 10 a.m. to noon. People who wish to become docents must register in advance by contacting Pamela Pelletier at 520-248-9933 or by email at

In the next phase of construction, a modern, climate-controlled archive will be built in the Mathematics East building to house the lab's extensive collection of wood samples, which range from pencil-thin cores of trees to 7-foot-diameter cross-sections of giant sequoias. The irreplaceable samples, the work of scores of scientists starting with Douglass, are still used by researchers as they continue to explore the wealth of information recorded in tree rings.

The collection is estimated to contain more than 2 million individual pieces of wood. Once complete, the new archive will allow the lab to double the amount of wood samples in the collection.

The lab received a $425,000 grant from the National Park Service and National Endowment for the Humanities' Save America's Treasures Program and a $484,000 grant from the National Science Foundation’s Collections in Support of Biological Research Program to purchase mechanical-compact shelving units to store the collection and to develop a digital database of the collections.

The Bryant Bannister Tree-Ring Building plus the renovation of the Mathematics East basement is primarily funded by private donation from Agnese Nelms Haury.

The UA Laboratory of Tree-Ring Research is recognized worldwide as a preeminent center for the advancement of tree-ring techniques and the broad application of dendrochronology in the social and environmental sciences.

Extra info


Open House at Laboratory of Tree-Ring Research


Bryant Bannister Tree-Ring Building, 1215 E. Lowell St.


Saturday, March 2, 10 a.m. to 4 p.m.

Guided tours will be offered every half-hour. Each tour will last about an hour. The last tour will begin at 3 p.m.


All the events are free and open to the public. The nearest free parking is available in the Sixth Street Garage located at 1201 E 6th St. The UA parking lots south of Sixth Street are also free on weekends.


Resources for the media

For information on the open house, contact:

Marianne Hamilton



For the Tree-Ring Docent program, contact:

Pamela Pelletier