Dendrochronology

Dendrochronology was originally created by A. E. Douglass (1867-1962) to assist in tracing the fluctuations in Earth’s climate. Since then, it has gained a popular reputation for its uses in archeological studies.[4, p.291]

“…dendrochronology is an extremely interdisciplinary science; its facets range from modern statistics on wood anatomy to the history of art. It is difficult even for dendrochronologists to keep in touch with the whole spectrum, and even more difficult for the layman to obtain an overall view of the many methods and fields of application.”[8, Preface]
– F. H. Schweingruber (2012)

Dendrochronology has given way to a number of subfields, such as dendroarchaeology, dendroclimatology, dendroecology, dendrogeomorphology, and dendrochemistry.[7, p.5]

Some trees don’t form rings.[7, p.7]

“…dendrochronological data provide a relatively short record, with only three tree-ring chronologies in the world that extend back 10,000 years or longer. These were developed from bristlecone pine (Pinus longaeva) in California (Ferguson et al. 1985), oak (Quercus spp.) in Ireland (Pilcher et al. 1984), and oak in Germany (Becker 1993, Friedrich et al. 2004).”[7, p.7]
– J. H. Speer (2010)

Definitions

Merriam-Webster’s Dictionary defined dendrochronology as: “the science of dating events and variations in environment in former periods by comparative study of growth rings in trees and aged wood”[1]

Dictionary.com defined it as: “the science dealing with the study of the annual rings of trees in determining the dates and chronological order of past events.”[2]

Lexico defined it as: “The science or technique of dating events, environmental change, and archaeological artefacts by using the characteristic patterns of annual growth rings in timber and tree trunks.”[3]

Its earliest known use dates to around 1928.[1] “First recorded in 1925–30; dendro- + chronology”[2]

Terminology

Signal-to-Noise Ratio[7, p.10]

Calibration[7, p.10]

Master Chronology[7, p.14]

Composite Chronology[9, p.1]

Concepts

Concept of Autocorrelation[7, p.18]

Concept of the Ecological Amplitude[7, p.20]

Concept of Standardization[7, p.23]

Principles

Principle of Uniformitarianism[7, p.10]

Principle of Crossdating[7, p.11]

Principle of Limiting Factors[7, p.15]

Principle of the Aggregate Tree Growth Model[7, p.17]

Principle of Site Selection[7, p.21]

Principle of Replication[7, p.23]

Methods & Techniques

Bridging-The-Gap Method[11, p.446]

List Method[7, p.14]

Memorization Method[7, p.14]

Method of Skeleton Plotting[7, p.13]

The Key-Year Crossdating Technique[10, p.54]

History

322 BCE: This is the earliest known example of someone thinking that trees gained an extra ring with each passing year. The thinker who thought the thought is known as Theophrastus.[7, p.30]

By 1498: The environment having an effect on the growth of trees was mentioned in Leonardo da Vinci’s Trattato della Pittura.[7, p.30] He commented on how the rings would either be thicker or slimmer depending on whether the year was drier than usual or wetter than usual.[7, p.28]

1581: Michel de Montaigne said that an anonymous carpenter claimed the ability to tell the age of a tree based on the number of rings it had.[7, p.28]

1737: While working in France, Henri Louis Duhamel du Monceau and George Louis Leclerc de Buffon noticed that the 29th ring in on multiple trees which had recently been cut down all had what appeared to be frost damage. They determined that the frost damage occurred in 1709 because one ring equals one year. Carl Linnaeus reported the 1709 frost ring in the Swedish trees that he examined.[7, pp.28-30]

1785: A tree that was marked for a trail in 1767 was reviewed by Friedrich August Ludwig von Burgsdorf. He found evidence that the tree did gain only one ring per year. Additionally, he found the 1709 frost ring in German trees.[7, p.29]

1811: De Witt Clinton became the earliest known person to employ dendrochronology for archeological purposes. He counted the rings in trees from the “earthen mounds near Canandaigua, New York” and argued that those mounds were not built by Europeans but by prehistoric Native Americans.[7, p.32]

1827: Alexander Catlin Twining “Used crossdating and noted the common signal across a site”.[7, p.30]

1837: Theodor Hartig “Set up the ecological basis for dendrochronology in Germany”.[7, p.30]

1838: Charles Babbage published “On the Age of Strata, as Inferred from Rings of Trees Embedded in Them”.[7, p.33]

1839-1840: The 1709 frost ring was found in French juniper trees by Alphonse de Candolle.[7, p.32]

1859: Jacob Kuechler “Used modern principles of site selection by choosing trees on low ridges with good drainage and used tables to note ring characteristics, demonstrating an early example of crossdating”.[7, p.30]

1866: “…the German botanist Julius Ratzeburg was probably the first to document an insect outbreak due to the effect of defoliation by caterpillars on tree rings (Ratzeburg 1866). He was able to assign absolute dates to the outbreak event by examining tree rings (Studhalter 1956).”[7, p.35]

1867: Robert Hartig laid the foundations for the majority of future European dendroecological research.[7, p.34] Between 1869 and 1901, Hartig published 34 papers on tree ring ecology and anatomy.[7, p.36]

1869: John Muir engaged in dendrochronological research.[7, p.35]

1871: A. L. Child “Compared tree growth in red maple to meteorological data for spring and summer”.[7, p.31]

1871: Adolph Stoeckhardt investigated the relation between air pollution and forest damage. This is among the earliest examples of this type of study.[7, p.35]

1873: Elias Lewis studied tree rings and attempted to date trees based on their diameter. This method of dating through diameter has since been shown to be a sketchy method.[7, p.35]

1880: Jacobus C. Kapteyn crossdated over 50 Germanic and Hollandic oaks to look for climatic patterns. This work of his was published in 1914.[7, p.37]

1881: “…Arthur Freihurr von Seckendorff-Gudent collected tree samples from 6410 Austrian black pines…”[7, p.36]

1882: Franklin Hough noted that insect outbreaks could potentially be dated by examining damage to trees.[7, p.35]

1892: F. Shvedov established himself as an early father of dendroclimatology by successfully predicting future droughts after examining trees.[7, p.37]

1897: B. E. Fernow “Wrote a paper on determining the age of blazing on trees by counting the tree rings”.[7, p.31]

1904: A. E. Douglass discovered the Flagstaff Signature. He also established the cornerstone of crossdating and earned himself the title “Father of Dendrochronology”.[7, p.37]

1911: Ellsworth Huntington sampled giant sequoia found close to Hume, California.[7, p.38]

1915: A. E. Douglass examined a giant sequoia from the same spot as Huntington. These trees established a chronology that dates back to 1305 BCE.[7, p.38]

1919: “…Douglass had collected 230 tree samples from the United States and Europe and he had measured 75,000 rings (Webb 1983).”

1935: A. E. Douglass founded the Tree-Ring Society.[7, p.40]

1937: A. E. Douglass founded the Laboratory of Tree Ring Research at the University of Arizona, a first of its kind.[7, p.28]

1938-1970: Bruno Huber published over 39 papers on dendrochronology which established him as one of the most important European dendrochronologists of his time.[7, p.39]

1950’s: Edward Schulman looked for older trees that would help establish long chronologies that could be used for climatic reconstructions. Additionally, he was the first to establish South American chronologies.[7, p.40]

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References:

[1] – “Dendrochronology.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/dendrochronology. Accessed 12 Oct. 2020.

[2] – https://www.dictionary.com/browse/dendrochronology?s=t. Accessed 12 Oct. 2020.

[3] – https://www.lexico.com/definition/dendrochronology. Accessed 12 Oct. 2020.

[4] – Webb, George E. “Solar Physics and the Origins of Dendrochronology.” Isis, vol. 77, no. 2, 1986, pp. 291–301. JSTOR, www.jstor.org/stable/232655. Accessed 9 Dec. 2020.

[5] – https://www.ltrr.arizona.edu/~cbaisan/Vermont/Erica/AED.pdf. Accessed 9 Dec. 2020.

[6] – https://lowell.edu/history/. Accessed 9 Dec. 2020.

[7] – James H. Speer. “Fundamentals of Tree-ring Research” (2010). https://books.google.com/books?id=XtxEbCzbKUUC&dq=limitations+of+dendrochronology&lr=&source=gbs_navlinks_s. Accessed 11 Dec. 2020.

[8] – Fritz Hans Schweingruber. “Tree Rings: Basics and Applications of Dendrochronology” (2012). https://books.google.com/books?id=iyGuBgAAQBAJ&dq=limitations+of+dendrochronology&lr=&source=gbs_navlinks_s. Accessed 11 Dec. 2020.

[9] – Brown, et al. “GIANT SEQUIOA RING-WIDTH CHRONOLOGIES FROM THE CENTRAL SIERRA NEVADA, CALIFORNIA” (1992). file:///C:/Users/carle/Downloads/Brown1992.pdf. Accessed 4 Jan. 2021.

[10] – Heikkenen, H. J., et al. “The Key-Year Dendrochronology Technique and Its Application in Dating Historic Structures in Maryland.” Bulletin of the Association for Preservation Technology, vol. 16, no. 2, 1984, pp. 53–55. JSTOR, www.jstor.org/stable/1494004. Accessed 4 Jan. 2021.

[11] – McGraw, Donald J. “Andrew Ellicott Douglass and the Big Trees: The Giant Sequoia Was Fundamental to the Development of the Science of Dendrochronology—Tree-Ring Dating.” American Scientist, vol. 88, no. 5, 2000, pp. 440–447. JSTOR, www.jstor.org/stable/27858092. Accessed 4 Jan. 2021.

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