Kiet Siel
Keet Seel, Navajo National Monument, AZ, tree-ring dated at 1250-1300 CE.  photo credit: Jeff Dean

General Information


Lecture times: Tuesdays and Thursdays, 9:30 - 10:45


Location: Bannister 110

Lab times: Tuesday, 2:00 to 5:00 pm

Location:  Bannister 110

Course Instructors:  

Associate Professor Valerie Trouet and Regents' Professor Malcolm Hughes

Office: Bannister Tree-Ring Building Rm 320 (Trouet) and Rm 421 (Hughes)

Phone:  626-8004

Office hours:     Trouet: Thursdays, 2:00-4:00pm or after appointment; Hughes:

Email:     and

Laboratory Instructor: M. Ross Alexander


Course Goals

In this course students will learn the scientific basis, techniques, and applications of dendrochronology. We will review the historical development and key discoveries of the field.  We will study the biological basis of tree-ring research and the central principles of dendrochronology. After studying fundamental concepts students will learn about applications of dendrochronology in different disciplines via lectures and discussions with leading dendrochronologists at the Laboratory of Tree-Ring Research. During intensive, weekly laboratory sessions and a weekend field trip students will learn the practical skills of specimen collection, preparation, observation, and the most important method and principle of dendrochronology -- crossdating.  At the end of the course, students will be able to collect tree-ring samples, prepare and date the samples, and build a local chronology. Finally, students will be able to evaluate dendrochronological analyses, and interpret their own data for specific research issues.


Required Readings

There is no required textbook for the course.

Required readings may be downloaded as Adobe Acrobat pdf files at a password protected site at:

The username and password for this site will be provided by the instructors.

Note that a full listing of the readings is at the bottom of this page. If you are unable to access the readings, tell one of the instructors. 

Readings should be completed before the class on that particular topic. It would also be a good idea for all students to browse the LTRR web site at, and especially the link to online bibliography, software and other dendrochronology information resources at


Lab is required for the course and will meet once a week for approximately 3 hours. The Lab constitutes a very important part of the course and of your grade. Topics covered in the lab include the practical aspects of crossdating, sample preparation and mounting, chronology building and interpretation, and the interpretation of different types of dendrochronological samples.

A detailed Lab syllabus is posted here: Lab Schedule 2016

A guide to Lab exercises and sample sets, and a suggested pace of work is posted here: Lab Exercises 2016

Please also find the lab handbook here: Lab Handbook

as well as guidelines for skeleton plotting and marking wood: guidelines

Mandatory Field Trip

There will be a mandatory weekend field trip on the weekend of October 15 and 16 to conduct dendrochronological sampling and to observe and learn about classic dendrochronology research topics and areas. Additional information about the field trip will be discussed in class. Methods demonstrated on the field trip will include site and tree selection criteria, increment coring techniques, and other field procedures in a problem-oriented context.

Evaluation and Grading

Four homework exercises are required for undergraduate students (see below for topics and due dates), and are designed to require students to read and evaluate relevant literature. For undergraduate students, there will be two exams, a mid-term and a final exam, covering the lecture materials. Graduate students will only take the mid-term exam. There will also be a practical Lab exam for all students covering the information and skills learned in the Lab. Finally, graduate students are required to (a) submit both electronically and as hard copy one annotated bibliography of the dendrochronological literature that includes at least 10 references-(see schedule for due dates), and (b) conduct, report, and present a research project specific to their area of interest (see below). The result should be in the form of a publishable paper or section of a thesis, dissertation, or proposal, and is due on the last regular day of class. Topics must be agreed with the instructors prior to submission.

Course components and points for undergraduates and graduates respectively:

Undergraduate students Graduate students
Homework 1-4 (25 X 4) 100 points Annotated bibliography 100 points
Mid-term Exam 200 points Mid-term Exam 200 points
Final Exam 250 points
Laboratory Exam 70 points Laboratory Exam 70 points
Lab Exercises 180 points Lab Exercises 180 points

Graduate Paper 200 points

Graduate Paper presentation 50 points
Undergraduate TOTAL 800 points Graduate TOTAL 800 points

Undergraduate grades
A 720 points
B 640 points
C 540 points
D 460 points
E < 460 points

Graduate grades

A 720 points
B 640 points
C 540 points
D 460 points
E < 460 point

  • Mid-Term and Final Exams are a combination of questions requiring short answers (a word, phrase or single sentence), and questions requiring longer answers (a paragraph or more). No incompletes will be given in this course, except under extraordinary circumstances.
  • There is no extra credit.

Lecture Schedule

Reading Topic
August 23 1: Introduction, Course Structure, Lab Intro, Biological basis of dendrochronology
August 25 Bowyer et al., CH 3, 4, 5 2: Biological basis of dendrochronology: wood anatomy, cells and tissues; LTRR Tour
August 30 Bowyer et al., CH 6 3. Biological basis of dendrochronology: wood structure and function
September 1 Bowyer et al., CH 1, Moser et al (2011) 4. Biological basis of dendrochronology: annual ring formation
September 6 Stokes and Smiley 1968 5. cross-dating
September 8 Lamarche and Harlan 1973 6. where do we find tree rings we can use?
September 13 Fritts et al. 1965 7. site and tree selection
September 15 Hughes 2011 8. chronology building: signal extraction
September 20 Hughes et al. 2011 9. chronology building: networks
September 22   10: chronology building: what can be measured?
September 27 Leavitt 2010, McCarol & Loader 2004 11: Isotopes in dendrochronology (Steve Leavitt)
September 29   12. History of Dendrochronology
October 4   Review session for midterm
October 6   Mid-Term Exam
October 11 Dean et al. 1996, Towner 2002 12. Southwest Dendroarcheology (Jeff Dean)
October 13   Dendrochemistry (Paul Sheppard)
October 15-16   Weekend Field Trip
October 18 Haneca et al. 2009 13. European dendroarcheology (Charlotte Pearson)
October 20 Falk et al. 2011, Kipfmueller and Swetnam 2001 7. Dendroecology: fire ecology (Erica Bigio)
October 25 Babst et al. 2014 19: tree rings in the carbon cycle (Soumaya Belmecheri and M. Ross Alexander)
October 27 Rozendaal and Zuidema 2011; Trouet et al 2012 18: Dendrochronology in the Tropics
November 1 O'Connor et al. 2015, Flower et al. 2014 8. Dendroecology: insect outbreaks (Ann Lynch)
November 3 Rice et al. 2009; Woodhouse and Lukas 2006 25: Dendrohydrology (Bethany Coulthard)
November 8 Meko and Woodhouse 2011 24: Dendrohydrology (David Meko)
November 10 Hughes and Brown, 1992; Hughes and Funkhouser 2003; Salzer et al, 2013 20: Charismatic paleoflora - working with trees that have lived for millennia
November 15 Fritts et al.1979, Stahle and Cleaveland 1992 21: Dendroclimatology: introduction (David Frank)
November 17 Cook et al. 2007 22: Dendroclimatology: techniques and networks
November 22 Diaz and Trouet 2014, Pederson et al. 2014 23: human-environment interactions (Kevin Anchukaitis)
November 24  No class - Thanksgiving
November 29 Graduate students present term paper to whole class
December 1 Review session for Final exam
December 6 FINAL EXAM 9.30-11.30am
December 6  Lab final exam (2-5pm)

Important Dates

September 20Homework #1 due (Undergraduate students)
September 29Graduate paper provisional topic due
October 6Mid-Term Exam (in class)
October 20Homework #2 due (Undergraduate students)
October 20Annotated Bibliography due (Graduate students)
November 3Homework #3 due (Undergraduate students)
November 17Homework #4 due (Undergraduate students)
November 29Graduate Student paper due and presentations
December 6, 2-5PMLab Practical Final Exam
December 6, 9:30- 11:30amFinal Exam

Undergraduate Homework Assignments

These assignments consist of a 1-page summary of an article in a scientific journal (not a web page!) pertaining to dendrochronology. The summary should include (a) the full reference of the article (i.e. how & where do I find it), (b) a summary of the main points of the work, and (c) a critical evaluation of the work (i.e. is it worth reading, and why?). The assignments must be submitted electronically to Professor Trouet at: and must have the word "Assignment" as the first word in the subject field.

Keep in mind that the quality and clarity of your writing, and spelling, punctuation, and grammar count!  Spell-check, grammar-check, and proof-read your summaries before submitting them.

Homework #1. Find, summarize and evaluate a peer-reviewed paper or part of a book containing information on a dendrochronological application of your choice. 25 points.

Homework #2. Find, summarize and evaluate a peer-reviewed paper or part of a book containing information on an application of dendrochronology in archeology. 25 points.

Homework #3. Find, summarize and evaluate a peer-reviewed paper or part of a book containing information on an application of dendrochronology in ecology. 25 points.

Homework #4. Find, summarize Find, summarize and evaluate a peer-reviewed paper or part of a book containing information on an application of dendrochronology in climatology or hydrology. 25 points.

The format is:

Nesvetajlo, V.D., Consequences of the Tunguska catastrophe: dendrochronoindication inference Planet. Space Sci., 1998, 46 (2/3): 155-161.

    An explosion or impact by an unknown, large body occurred at about 6 to 8 km. elevation above the region of Tunguska in east-central Siberia on June 30, 1908. This resulted in damage for 60-80 km around an epicenter, with many millions of trees being blown down. The author visited the epicenter in 1990 and took increment cores from some of the trees left standing at the epicenter. He reports an attempt to infer details of the event from the nature of the rings formed in these trees in 1908 and subsequent years. His main findings were???. The data provided only partially support these conclusions because?.. The importance of these results is?.. The study could be extended and improved if the following were done??.. This is an informative and readable paper, based on careful work, although I found the author's interpretation of his observations to be somewhat unconvincing. Even so, he has laid the groundwork for future studies that could be informative.

Graduate Student Annotated Biblography

Graduate students are required to prepare an annotated bibliography of scientific literature relating to dendrochronology and specifically to the topic of their graduate paper. At least 10 separate papers, book chapters, reports, monographs, etc. must be included. The required class readings can be included in this bibliography, but they do not count toward the minimum 10 papers. In addition to a full citation for the work, a succinct summary of the most important points of the paper should be provided, along with your own assessment and judgement of the findings and values of the paper and how it fits in the context of the graduate paper. These summary statements should not simply be condensed versions of the paper's abstract, but should clearly show your own evaluation of the paper.

Graduate Student Papers

The Graduate Student Paper should be a 10-15 page report (minimum type size 11 point, double spaced, 1 inch margins) on some original research, a pertinent literature review, or a proposal soliciting funding for a specific project. Depending on the type of project you choose, your paper should include (at a minimum) introduction, background research/discussion of the problem, field and lab methods, results, discussion, conclusion, and references cited sections. (A literature review is somewhat different--see me if you have questions).

The paper should be formatted in the style used by the major journal in your field (i.e. American Antiquity for archaeologists, The Holocene or International Journal of Climatology for paleoclimatologists, etc.). References, figures, and tables are included in the page limit. Figures and tables should be legible, but I do not require that they be publication quality. The paper will be assessed both in terms of its content and in terms of the quality of the writing and presentation. Grammar, spelling, punctuation, style, and layout all count!

I encourage you to write something that fits precisely the requirements of this class, but that also serves some other purpose, for example a chapter of your thesis or dissertation, a paper for publication, or a proposal. This economy of effort, however, does not extend to using the same paper for two or more classes!

Attendance and Rules of Conduct

  • Attendance at all lectures and lab sessions is important and is expected, but is not included in grade calculation. All holidays or special events observed by organized religions will be honored for those students who show affiliation with that particular religion.
  • Absences pre-approved by the UA Dean of Students (or Dean's designee) will be honored. Excessive absences may be grounds for dropping a student from the course. It is, however, the student's responsibility to drop the course officially; failure to do so will result in a grade of E or I, at the instructor's discretion.
  • If you must arrive late or leave early (something not encouraged), please do so quietly; noisy entrants will be required to leave immediately.
  • Cell phone usage, web browsing or reading of materials unrelated to the lecture or lab (e.g., newspapers, magazines, etc.) are disruptive, and are prohinited in class. Students who exhibit disruptive behavior may be administratively dropped from the course at the Instructor's discretion.
  • Discrimination on the basis or race, religion, ethnicity, gender, sexual orientation, physical disability is prohibited by UA and other policies.  Violence will not be tolerated in the classroom. This prohibition includes, but is not limited to, verbal, written, or internet activities. Anyone observed using any racist or derogatory language, writing offensive materials, or downloading pornography or other objectionable materials will be required to leave the class and may be administratively dropped from the course at the Instructor's discretion.
  • Cheating will not be tolerated and is grounds for expulsion from the course; cheating includes, but is not limited to: copying work of others during exams or homework; turning in any work of others as your own, including work of students from past semesters; plagiarism on papers. Click here for definitions and discussion of plagiarism.
  • Students found cheating on any assigned work will receive a score of 0 for that assignment and will be reported to the Dean of Students. A second violation is grounds for expulsion from the course.

    Special Provisions
  • In compliance with Title III of the Americans With Disabilities Act (1990), students who require special assistance will be suitably accommodated. Students must be registered with the University and a minimum of 5 days notice for such accommodations is requested.
  • If the schedule conflicts with major religious observances, please let the professor know.
  • If English is not your native language and you believe that you must use a translation dictionary during exams, please contact the professor.
  • Students requiring accommodation in testing or note taking: Please notify the professor and provide the Disability Resource Center letter within the first few days of the course.
  • Student athletes and others who need signatures periodically: Please notify the professor that you'll be needing signatures generally, and please alert the professor before a particular signing period is due so that your most up-to-date grade can be calculated.
  • Honors College students: An Honors Contract is allowable. See the instructor to arrange those details

Readings List

Babst et al. (2014) A tree-ring perspective on the terrestrial carbon cycle. Oecologia DOI 10.1007/s00442-014-3031-6

Bowyer, J.L., Shmulsky, R. and Haygreen, J.G. (2007) Forest Products and Wood Science: An Introduction. See schedule for details.

Dean, J.S., M.C. Slaughter and D.O. Bowden (1996). Desert dendrochronology: tree-ring dating prehistoric sites in the Tucson Basin. Kiva 62, 7 - 26.

Diaz and Trouet (2014) Some Perspectives on Societal Impacts of Past Climatic Changes. History Compass doi:10.1111/hic3.12140

Falk et al. (2011) Multi-scale controls of historical forest-fire regimes: new insights from fire-scar networks. Frontiers in Ecology and the Environment doi:10.1890/100052

Fritts, H.C. (1976). Tree Rings and Climate. Academic Press, London. Pages 55 - 68.

Fritts, H.C., G.R. Lofgren and G.A. Gordon (1979) Variations in climate since 1602 as reconstructed from tree rings. Quaternary Research 12, 18 - 46.

Fritts, H.F., D.G. Smith, J.W. Cardis and C.A. Budelsky (1965). Tree-ring characteristics along a vegetation gradient in Northern Arizona. Ecology 46, 393-401.3.

Haneca et al. (2009) Oaks, tree rings and wooden cultural heritage: a review of the main characteristics and applications of oak dendrochronology in Europe. Journal of Archaeological Science 36:1-11.

Hughes, M.K. (2011) Dendroclimatology in high-resolution paleoclimatology. IN M.K. Hughes et al. (eds.), Dendroclimatology, Progress and Prospects. Springer, Berlin, pp. 17 - 34.

Jacoby, G.C., P.R. Sheppard and K.E. Sieh. Irregular recurrence of large earthquakes along the San Adreas Fault: Evidence from trees. Science (1988) Science 241:196-199.

Kipfmueller, K. F. and T. W. Swetnam (2001) Using dendrochronology to reconstruct the history of ecosystems. Chapter 8, pages 199-228, In D. Egan and E. A. Howell eds., Techniques for Discovering Historic Ecosystems. Island Press, Washington.

LaMarche, Jr., V.C., and T.P. Harlan (1973). Accuracy of tree-ring dating of bristlecone pine for calibration of the radiocarbon time scale. Journal of Geophysical Research 78, 8849 - 8857.

Leavitt, S.W. (2010). Tree-ring C-H-O isotope variability and sampling. Science of the Total Environment in press

McCarroll, D, and N.J. Loader. (2004) Stable isotopes in tree rings. Quaternary Science Reviews 23:771-801.

Meko, D.M. (2006) Tree ring inferences on water-level fluctuations of Lake Athabasca. Canadian Water Resources Journal 31(4):1-20.

Meko, D.M. and Woodhouse, C. (2011) Application of streamflow reconstruction to water resources management. IN M.K. Hughes et al. (eds.), Dendroclimatology, Progress and Prospects. Springer, Berlin, pp. 231 - 261.

Moser, L. et al., (2011) Timing and duration of European larch growing season along altitudinal gradients in the Swiss Alps. Tree Physiology 30: 225-233.

Pederson et al. (2014) Pluvials, droughts, the Mongol Empire, and modern Mongolia. PNAS 111: 4375-4379.

Rice, J.L. et al. (2009) Science and decision making: water management and tree-ring data in the Western United States. Journal of the American Water Resources Association 45: 1248-1259.

Rozendaal, D.M.A. and Zuidema, P.A. (2011) Dendroecology in the tropics: a review. Trees 25: 3-16.

Salzer, M.W., Hughes, M.K., Bunn, A.G. and Kipfmueller, K.F. (2009) Recent unprecedented tree-ring growth in bristleone pine at the highest elevations and possible causes. Proceedings of the National Academy of Sciences. 106: 20348- 20353.

Stahle, D. W. and M.K. Cleaveland (1992) Reconstruction and analysis of spring rainfall over the southeastern U.S. for the past 1000 years. Bulletin of the American Meteorological Society 73, 1947 - 1961.

Stokes, M.A., and T. L. Smiley (1968). An Introduction to Tree-Ring Dating, University of Arizona Press, Tucson. (Reprinted 1995).Pages xi - xiii, xv - xvii, 3 - 20.

Towner, R.H. (2002) Archeological Dendrochronology in the Southwestern United States. Evolutionary Anthropology 11: 68-84.

Trouet et al. (2012) Cambial growth season of brevi-deciduous Brachystegia spiciformis trees from South Central Africa restricted to four months. PLoS ONE 7(10): e47364.

Woodhouse, C.A., S.T. Gray, and D.M. Meko (2006) Updated streamflow reconstructions for the Colorado River. Water Resources Research 42, W05415, doi:10.1029/2005WR004455.

Yamaguchi, D. K. and D.B. Lawrence (1993) Tree-ring evidence for 1842 - 1843 eruptive activity at the Goat Rocks dome, Mount St. Helens, Washington. Bulletin of Volcanology 55, 264 - 272.

Important Note:

Information contained in this course syllabus, other than the grade, absence and other UA policies, may be subject to change with reasonable advance notice, as deemed appropriate by the instructor.