The annual growth rings from trees provide us with an incredibly powerful and adaptable tool to study Earth’s history. The rings tell us much more than just the age of tree. They also provide clues that help us understand how our environment has changed in the past, and provide insights into how key processes in atmosphere, biosphere and geological systems operate over long timescales. This course will teach students the fundamental principles of dendrochronology through a combination of formal lectures, class discussion and laboratory exercises. Students will work in the University of Minnesota’s Center for Dendrochronology, where they will learn how to collect, prepare and date tree-ring specimens. By the end of the course, they will be able to explain both the key concepts underlying dendrochronology and discuss how evidence from tree rings is used to address contemporary issues in natural history, resource management and Earth Systems Science.

1. I N T R O D U C T I O N TO D E N D R O C H R O N O LO GY

3. 2010 Dec-Nov temperature anomaly h p://www.giss.nasa.gov/

4. NASA global temperature record h p://www.giss.nasa.gov/

5. QUESTION
Is it unusual for the world to be this warm?

6. Water transfers in the American southwest
Courtesy Glen MacDonald

7. Low reservoir
Photograph: Glen MacDonald

8. QUESTION
Is there enough water in the Colorado River
to satisfy the expected need?

9. Photograph: watsonsinelgin

10. Photograph: Howard Arno

11. QUESTION
When were these dwellings
constructed (and abandoned)
and why?

12. Photograph: Tom Swetnam

13. Photograph: WhineAndDine

14. QUESTION
How does weather and climate affect the
risk and severity of forest fires?

15. Red River
Manitoba
Photograph: Greg Brooks

16. AP Photo/U.S. Coast Guard, Lt. Brendan Evans

17. QUESTION
How often does the Red River
produce extreme floods?

19. Tree at Chancellorsville
Photograph: Andy Frasse o

21. Tree-ring display at elementary school
Photograph: Tom Swetnam

23. “ The trees composing the forest rejoice and
lament with its successes and failures and
carry year by year something of its story in
their annual rings.”
A. E. Douglass
University of Arizona

24. Same environmental conditions
Similar
growth pa erns

25. 25

26. THE PRINCIPLE OF CROSS-DATING
1900 1910 1920 1930
Two Douglas-fir cores from Eldorado Canyon, CO
Graphic: Jeff Lukas, INSTAAR

27. Frost damage Photograph: Howard Arno
Photo: Howard Arnott

28. Fire scars

29. The science of dendrochronology uses
information encoded into the annual growth rings
of trees to address issues related to climate
change, hazards, ecology and natural history.

30. Giant sequoia 3,266 years Photograph: Chris Mullins
Photo: Chris Mullins

31. Bristlecone pine 4,844 years Photograph: Tom Harlan

32. White pine 1714
Photo: Kurt Kipfmueller

33. White cedar 1452
Photo: Danny Margoles

34. I N T R O D U C T I O N TO D E N D R O C H R O N O LO GY

35. Fundamentals Tree-ring anatomy Photograph: Kevin Anchukaitis

36. Fundamentals Weather, climate and tree growth Photograph: dr_tim_1956

37. Fundamentals History of dendrochronology

38. Fundamentals Statistical tools for tree-ring analysis

39. Applications Drought risks Photograph: Library of Congress

40. Applications Fire ecology Photograph: Don Falk

41. Applications Natural hazards and landscape processes Photograph: Erica Bigio

42. Applications Forest ecology Photograph: Whitney Crawford

43. Applications Maritime archeology 43

44. I N T R O D U C T I O N TO D E N D R O C H R O N O LO GY

45. Who am I?

50. Tree-ring display at elementary school
Photograph:Tom Swetnam

52. Photograph: Dave Sauchyn

54. Photo: Calvin Ferris Kurt Kipfmueller University of Minnesota

56. umndendro.umn.edu

57. GEOG3839 Nuts and bolts
GEOG5839

58. Links to course syllabus, schedule
at h p://umn.edu/~stgeorge under ‘Teaching’

61. GRADING WEIGHTS
GEOG3839
Mid-term 30%
Exercises (4) 40%
GEOG5839
Final exam 30%
Mid-term 20%
Exercises (4) 40%
Project 40%

63. Trees are among the oldest living things on our planet. Many trees can live for
several centuries and a few exceptional specimens have survived for more
than 5,000 years. In part because of their great age, the annual growth rings
from trees provide us with an incredibly powerful and adaptable tool to study
Earth’s history. The rings tell us much more than just a tree’s age. They also
provide clues that help us understand how our environment has changed in
the past, and provide insights into how key processes in atmosphere,
biosphere and geological systems operate over long timescales.
The science of dendrochronology uses information encoded into the annual
growth rings of trees to address issues related to climate change, hazards,
ecology and natural history. Because tree vitality is strongly influenced by
local environmental conditions, major events such as a change in climate,
insect a ack or severe flood o en create a distinct ‘fingerprint’ in the tree’s
rings. By studying these signatures in the rings, we can develop an annual
record of past environmental events extending back several centuries or
millennia.

65. Links to course syllabus, schedule
at h p://umn.edu/~stgeorge under ‘Teaching’

66. Readings!
Smith and Lewis (2006), Dendrochronology

67. What can you expect to learn?

70. DENDROCHRONOLOGY is much more
than just counting tree rings