Tree-ring Studies at Centralia College

Using dendrochronology to study climate and environmental and geologic history

updated April 30, 2018

Why study tree rings?

     Dendrochronology is the study of tree rings, including the measurement and dating of tree rings in living and "subfossil" trees. Subfossil trees are dead and preserved, but not permineralized (petrified). The study of tree rings has many practical applications. It is the best technique used to assertain dates on past events to the year. The Laboratory of Tree-Ring Research (LTRR) at the University of Arizona has a good introduction to tree-ring dating.  The Tree Ring Lab (TRL) at the Lamont-Doherty Earth Observatory is also an excellent source of information about tree ring studies and is also a source of software of use in tree-ring studies.

The Centralia College Tree-Ring Lab

The tree-ring lab is located in the "new" Natural Sciences Building. constructed in 2009 and is adjacent to the Kiser Natural Outdoor Learning Laboratory, a natural area that has been integrated into the campus and deedicated to educational purposes including scientific studies. The lab is withing walking distance of the Seminary Hill Natural Area and within easy driving distance of the O'Neill Natural Area, a 20-acre forest parcel that was donated to the college for educational activies by Robert and Doris O'Neill.

Lab facilities: The Centralia College dendrochronology lab for undergraduate instruction and research is fully equiped for doing tree-ring research. The lab equipment can support a full range of dendrochronology activities including sample collection from both living and subfossil trees, sample preparation, and tree-ring analysis. The equipment includes more than 25 increment borers (16–32 in), saws of various kinds (including handsaws and wiresaws for field collection of subfossil wood, and a Grizzly bandsaw for processing larger speciment). The tree-ring lab contains all the necessary equipment for mounting and polishing speciments including three belt sanders, a full collection of abrasive papers as fine as 2,000 grit as well as a supply of 0000 steel wool; glue, clamps, and tape. An Epson 10,000XL scanner allows scientific measurements to 0.01 mm precision. A smaller Epson 1680 is also available for scanning polished speciments. The Velmex measuring stage has a Unislide mechanism, a linear encoder, and a digital readout.  We have 9 stereomicroscopes, seven of which are Fisher trinocular stereozoom scopes. One of the trinocular scopes is mounted on a large boom stand for measuring of large samples. We have two microscope-adapted digital video cameras as well as miscellaneous field equipment including measuring tapes, compasses, and gps units (2).

Computer and technology capabilities: The lab has five Dell computers, three of which are connected to 4 Tb external hard disks for plenty of storage space; one computer is connected the campus weather station, a Davis VistaPro2, and to an HP Designjet Printer (plotter) capable of making posters as wide as 48 in. An adjoining dedicated science computer lab contains 13 computers loaded with science software including ImageJ image analysis software for measuring tree rings, and twenty Science Department laptops are available on an ad hoc basis.  All labs are wifi enabled. The Velmex measuring system is supported by Voortech Measure J2X software. Windendro analysis software is loaded on one computer for higher-tech analysis. Vuescan software for image capture is loaded on both computers that are connected to scanners.

Office capabilities: The Natural Science Building has a copy machine, fax machine, and other standard office equipment and facilities.

Tree rings and field studies at Centralia College

Tree-ring studies—Undergraduate research in the Cascade Range and Puget Lowland  

Tree-ring research at Centralia College
—A powerpoint presentation by Pat Pringle at the 2013 NAGT field conference, SOCC Coos Bay OR

Tree-rings studies at Seminary Hill Natural Area in Centralia, Washington 

Tree-ring studies at O'Neill Natural Area   

"From the Core" — A short video about a class dendrochronology project, by Laura Joy Griffith

Tree-ring web sites

The ultimate tree-ring web pages, by Henri Grissino-Mayer

TREX—Tree-ring Expeditions   Tree-ring research activities for undergraduate sciences

Pat's tree-ring links   (includes links to manuals and software sites)

Books about tree rings

Agee, J.K., Huff, M.H. 1986. The care and feeding of increment borers. CPSU/UW 86(3): 1-14.  [accessed on July 18, 2012 at ]; also in KIRK LIBRARY Pringle e-reserves

Fritts, H.C. 1976. Tree Rings and Climate: Academic Press, New York, 567 pp.

Speer, J.H., 2010,  Fundamentals of Tree-Ring Research:  The University of Arizona Press.  324pp.

Stokes, M.A.; Smiley, T.L. 1968. An Introduction to Tree-Ring Dating: University of Chicago Press, Chicago, IL, 73 pp.  


Henri Grissino Mayer's list of dendro references  

Pat's weather and climate links