1. History of Tree-Ring Research I
January 14, 2009

2. Scientists That Have Explored Tree Rings
Theophrastus of Erusus
Greece 322 B.C.
Pupil of Aristotle
Wrote “History of Plants” in 9 volumes
Last volume titled “Causes of Plants”
Mentioned growth rings in two fir species
Recognized the annual nature of tree rings

3. Leonardo da Vinci
“Rings in the branches of sawed trees show the number of years and, according to their thickness, the years which were more or less dry. Thus, they reflect the individual worlds to which they belong, in the north [of Italy] they are much thicker than in the south.”

4. Duhamel du Monceau, H. -L. , and Comte de Buffon, G. L. L. 1737
Duhamel du Monceau, H.-L., and Comte de Buffon, G.L.L Recherches de la cause de l'excentricité des couches ligneuses qu'on appercoit quand on coupe horizontalement le tronc d'un arbre; de l'inégalité d'épaisseur, and du different nombre de ces couches, tant dans le bois formé que dans l'aubier. [Investigations into the cause of the eccentricity of the woody layers that one observes when the trunk of a tree is horizontally cut; inequality in thickness, of different numbers of these layers, as well as the wood formed in the sapwood.] In: P. Mortier, ed., Histoires de l'Académie Royale des Sciences Année 1737, avec les Mémoires de Mathématique & de Physique, pour la meme Année. Amsterdam:
Henri-Louis Duhamel du Monceau

5. Twining, A. C. 1833. On the growth of timber
Twining, A.C On the growth of timber. American Journal of Science and Arts 24:
“Every tree had preserved a record of the seasons, for the whole period of its growth…might not this natural, unerring, graphical record of seasons past, deserve as careful preservation as a curious mineral or a new form of crystals?”
“Such a comparison… might prove the means of carrying back our knowledge of the seasons, through a period coeval with the age of te oldest forest trees.”

6. Charles Babbage (1791 – 1871)

7. Theodor Hartig Robert Hartig
Professor at Forest Academy, Eberswalde Germany
“On the Development of Annual Rings in Woody Plants.” , in Uber die Entwicklung des Jahresringes der Holzpflanzen
Botanist interested in forest growth = silviculture
Professor of Forestry Sciences at the University of Berlin

8. Jacob Kuechler in Texas in 1859
Campbell, T.N The pioneer tree-ring work of Jacob Kuechler. Tree-Ring Bulletin 15(3):
Kuechler was a forester from Germany, settled in Texas in 1847.
“Our records are of such recent date that we must turn to the annals of Nature, particularly of the plant world. A tree contains the record of its life history, and this history is most closely interwoven with the annual rainfall.”
Used post oak trees (Quercus stellata) that 125 years later proved to be critical for understanding past climate in the south-central U.S.
Noted repeating patterns of dry years and wet years in the ring record.

9. Enos Mills (1838–1922)
John Muir (1838–1914)

10. Andrew E. Douglass ( )
is regarded as the “father” of
Dendrochronology. Douglass was a
student of the famous astronomer
Percival Lowell who, in 1894, sent
Douglass across the country to
build an observatory in Arizona.
While acquiring the timber for the
observatory’s construction,
Douglass noticed similar ring-width
patterns in the stumps of the trees
cut for construction.
By the early 1920s, Douglass had
pioneered the science of dendro-
chronology, most importantly,
the principle of crossdating which
he applied to a variety of different
disciplines from climatology to
astronomy to archaeology.

11. In 1914, he was approached by Clark Wissler of the American Museum of Natural History and asked if his method of tree-ring dating could be used to date the famous Indian ruins scattered throughout the American Southwest, one of the great archaeological mysteries of its time. This began a 15 year quest to date the years of construction for many Puebloan sites in several states, eventually funded by the National Geographic Society. This slide shows Cliff Palace at Mesa verde Nat park in southwestern Colorado, one of many sites he visited and collected wood samples.

12. Another site he visited was the famous set of ruins in Chaco Canyon
Another site he visited was the famous set of ruins in Chaco Canyon. Above is Pueblo Bonito as it appeared in the early 20th century. Douglass eventually collected wood (core) and cross section samples from nearly 30 sites in the Southwest.

13. He and his colleagues were frustrated however because they could not connect the living tree chronology with the tree-ring chronology developed from all the ruins in the Southwest. Until this sample, HH-39, collected in June This bridged the gap between the two chronologies and effectively helped date all the ruins that Douglass had analyzed to that point. This event is considered one of the milestones in archaeology, and brought tree-ring science into the mainstream. The research was also featured in December 1929 in National Geographic Magazine.

14. Douglass, A.E The secret of the southwest solved by talkative tree rings. National Geographic Magazine 56(6):

15. Douglass in Storeroom
Laboratory of Tree-Ring Research Tucson, Arizona 1940

16. Florence Hawley

18. Bruno Huber (1899 – 1969)

19. Edmund Schulman (1908 – 1958)

20. Edmund Schulman (1908 – 1958)

22. Harold C. Fritts (1928 – )

23. Fritz H. Schweingruber (1935 – )

24. Thomas W. Swetnam
1955 –

25. Malcolm K. Hughes

26. Edward R. Cook

27. David W. Stahle

28. Subfields of Dendrochronology
Dendroarchaeology: Dating of Archaeological dwellings.
Dendroclimatology: Developing a record of past climate.
Dendrogeomorphology: Dating land movements such as landslides in the past.
Dendrohydrology: Creating a record of past water availability and flooding.
Dendroglaciology: Dating past movements of glaciers.
Dendrovolcanology: Dating the past eruptions of volcanoes.
Dendrochemistry: Using tree rings as a monitor of the chemical makeup of the soil.
Dendroecology: Recording ecological processes such as tree-line movement, insect outbreaks, or movement of invasive tree species.
Dendropyrochronology: Dating the past occurrence of forest fires.
Dendroentomology: The use of tree rings to reconstruct past population levels of insects.
Dendromastecology: The use of tree rings to reconstruct fruiting events in trees.

29. Individual tree species that can live to more than 1,000 years, that we know of?
Intermountain bristlecone pine (Pinus longaeva D.K. Bailey), 4,844 years old
Alerce (Fitzroya cuppressoides (Molina) Johnston), 3,620 years old
Giant sequoia (Sequoiadendron giganteum (Lindl.) Buchholz), 3,300 years old
Rocky Mountain bristlecone pine (Pinus aristata Engelm.), 2,425 years old
Coast redwood (Sequoia sempervirens (D.Don) Endl.), 2,200 years old
Foxtail pine (Pinus balfouriana Grev. & Balf.), 2,110 years old
Rocky Mountain juniper (Juniperus scopulorum Sarg.), 1,889 years old
Limber pine (Pinus flexilis James), 1,670 years old
Alaska yellow-cedar (Chamaecyparis nootkatensis (D.Don) Spach), 1,636
Baldcypress (Taxodium distichum (L.) Rich.), 1,622 years old
Western juniper (Juniperus occidentalis Hook.), 1,288 years old
Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), 1,275 years old
Huon pine (Lagarostrobus franklinii C.J. Quinn), 1,089 years old
Northern white-cedar (Thuja occidentalis L.), 1,032 years old
Himalayan Hemlock (Tsuga dumosa) 1,011 years old

30. International Tree Ring Data Bank (ITRDB)

31. ITRDB: International Tree-Ring Data Bank
ITRDB Web site

32. The Ultimate Tree-Ring Web Pages: