Laboratory of Tree-Ring Research

Laboratory of Tree-Ring Research
Name	Laboratory of Tree-Ring Research
Established	1937
Founder	A. E. Douglass
Location	Tucson, Arizona
Parent institution	University of Arizona

Contents

Laboratory of Tree-Ring Research is a dendrochronology center founded to study annual growth rings in trees for applications across climatology, archaeology, ecology, and history. The laboratory has produced chronologies used by researchers at Smithsonian Institution, National Aeronautics and Space Administration, National Oceanic and Atmospheric Administration, and international partners in Canada, Mexico, Chile, Peru, and Spain. Its work has informed studies linked to Little Ice Age, Medieval Warm Period, Dust Bowl, Great Basin, and Rocky Mountains environmental histories.

History

The laboratory was established by A. E. Douglass in 1937 at University of Arizona after collaborations with scholars from Harvard University, Carnegie Institution for Science, Yale University, Columbia University, and University of California, Berkeley. Early projects connected to excavations at Chaco Canyon, Mesa Verde, and Casa Grande engaged archaeologists such as Nels C. Nelson, Edgar Lee Hewett, Sylvia Mae, and Gordon V. Benson. During the mid-20th century the lab collaborated with the United States Geological Survey, Forest Service, Smithsonian Institution, and researchers funded by the Rockefeller Foundation and the National Science Foundation. Key figures have included H. C. Fritts, Ed Cook, Tom Swetnam, Paul Colinvaux, Gary A. Rol}}, and Clifford D. Jacobs. The laboratory contributed datasets cited in work by Raymond S. Bradley, Michael E. Mann, Philip D. Jones, Jonathan Overpeck, and W. S. Broecker.

Research emphasizes crossdating techniques pioneered by A. E. Douglass and refined by researchers such as H. C. Fritts, Ed Cook, Thomas W. Swetnam, and Brendan Buckley. Methodological advances integrate isotopic analysis used by teams at Lawrence Berkeley National Laboratory, Oak Ridge National Laboratory, and Los Alamos National Laboratory alongside stable carbon and oxygen studies linked to University of California, Los Angeles, University of Colorado Boulder, and Columbia University investigators. Statistical approaches draw on methods from George E. Box, Herman Wold, and Karl Pearson-influenced traditions applied in work with National Center for Atmospheric Research and Paleoclimatology consortia. The lab uses increment borers and X-ray densitometry comparable to protocols at Swiss Federal Institute for Forest, Snow and Landscape Research, University of Bern, and Stockholm University. Collaboration with Max Planck Society affiliates and researchers from University of Oxford and University of Cambridge extends techniques to tropical chronologies evaluated against records from James Cook University and University of Auckland.

Collections include wood specimens from Chaco Canyon, Mesa Verde, Cerro Blanco (Peru), Elqui Valley, and the Sierra Nevada (United States), assembled alongside artifacts from Pueblo Bonito, Aztec Ruins National Monument, and Casa Grande Ruins National Monument. The collection holdings have been used in comparative studies with samples housed at Museum of Northern Arizona, American Museum of Natural History, Field Museum, Peabody Museum of Archaeology and Ethnology, and British Museum. Facilities include climate-controlled repositories, X-ray densitometry suites paralleling equipment at European Synchrotron Radiation Facility, stable isotope labs similar to those at Max Planck Institute for Chemistry, and dendroscopes akin to installations at University of Freiburg. Collaborations with Arizona State Museum, Tucson Botanical Gardens, Arizona-Sonora Desert Museum, and Desert Laboratory (Harvard) support curation and comparative research.

Major projects include reconstruction of Southwestern droughts intersecting with research on the Ancestral Puebloans, chronologies used in dating Anasazi sites, and long tree-ring records employed by IPCC-related paleoclimate syntheses authored by Michael E. Mann, Phil Jones, Raymond S. Bradley, and Ed Cook. The lab contributed to high-profile datasets used in comparisons with ice-core records from Greenland, Antarctica, and speleothem records from Cueva de Villa Luz and Sierra de las Minas. Collaborations with US Forest Service and Bureau of Land Management informed wildfire history studies alongside work by Scott L. Stephens and Jessica E. Davis. Notable grants supported projects with National Science Foundation, NASA, NOAA, and partnerships with Smithsonian Institution curators.

The laboratory is administratively affiliated with University of Arizona and collaborates with institutions including Smithsonian Institution, National Park Service, US Geological Survey, US Forest Service, National Science Foundation, National Aeronautics and Space Administration, National Oceanic and Atmospheric Administration, and international partners such as CONACYT (Mexico) and FONDECYT (Chile). Funding has come from competitive awards from National Science Foundation, research grants from National Institutes of Health, programmatic support from NASA, philanthropic gifts from Rockefeller Foundation and Carnegie Corporation of New York, and project-specific support from Bureau of Land Management and National Park Service.