In Blog, Temporalities-Blog

Reading history in wood: how tree rings became an imperial device

susanne quitmann

 

How dendrochronology — the science of reading tree rings — emerged in the early 20th-century American Southwest as a dating tool as well as an instrument of epistemic imperialism that imposed Western timelines onto Indigenous histories.

Trees and history

Trees are the material from which histories are made. Quite literally, they have long supplied the paper on which historical narratives are written (in analogue formats at least). Yet their relationship to history goes much deeper. Trees contain histories. Each year, they add a new ring to their trunks, preserving traces of the past as they grow. In the early 20th century, scientists began to study these rings to learn about the past. By measuring tree rings and comparing their patterns, scientists created long chronological records that stretched centuries — and eventually millennia – into the past. This method, known as dendrochronology, promised to date not only trees but also wooden artefacts with remarkable precision from periods when written sources did not exist. But analysing tree rings required interpretation, and the chronologies built from them were neither natural nor objective. The history of dendrochronology demonstrates that dating methods and temporal scales are powerful epistemological devices that determine what kinds of historical narratives can be constructed. In the early 20th-century, dendrochronology emerged in the United States as a scientific technique as well as a tool of imperial control. It was used to impose a Western timeline onto Indigenous history, reinforcing structures of knowledge and authority.

Of tree rings and sunspots

To understand how tree rings became historical markers, we need to look back to the surprising origins of dendrochronology. Rather than archaeology or history, it grew out of astronomy.[1] Arizona-based astronomer Andrew E. Douglass was fascinated by sunspots and their potential relationship to our climate. Scientists had long suspected that solar activity might influence weather patterns, but proving such a connection required long records of astronomical and weather data. Here, Douglass was faced with a problem: at the time, meteorological archives for the United States dated back decades, not centuries – insufficient for studying long-term solar cycles. So, Douglass began searching for alternatives, and trees provided a solution. Every year, most trees add a new growth ring to their trunks: light and pale in spring and early summer, dense and dark in late summer and autumn. In years when rainfall is plentiful and conditions are favourable, the rings grow wide. In dry or stressful years, they grow narrow. Because these variations reflect climate conditions, tree rings serve as a natural archive of weather events and climate conditions. By measuring and comparing rings across multiple trees, Douglass could reconstruct sequences of wet and dry years stretching far back into the past.

A new scientific discipline

By the mid-1910s, Douglass realised that tree rings might have applications far beyond astronomical research. He first suggested in 1916 that the technique could date archaeological remains.^[2] At the time, archaeologists working in the North American Southwest were excavating numerous Indigenous sites but lacked reliable methods to determine their age and their temporal relationship to one another. There were no written chronologies prior to Europeans’ arrival, leaving earlier centuries largely undated.[3] But if wooden beams from archaeological sites contained the same pattern of rings found in living trees, those beams could be dated by matching the patterns. This 'cross-dating' allowed researchers to determine the year (or period, depending on how the wood had been processed) in which the wood had been processed. Over the next 13 years, Douglass, together with anthropologists and archaeologists,  collected wood samples from ancient structures and living trees across the American Southwest. By comparing overlapping patterns from many trees and wooden beams, Douglass gradually assembled a long chronological sequence, a master timeline of ring patterns across the region inhabited by the Hopi. Eventually, this sequence stretched back roughly 2000 years. In 1929, Douglass published his landmark results.^[4] For the first time, archaeologists could date wooden samples and relics from sites with remarkable precision. A new scientific discipline was born. Fig. 3: Andrew E. Douglass, “The Secret of the Southwest Solved by Talkative Tree Rings.” The National Geographic Magazine 56 (1929): 737-70, p. 769. The term dendrochronology – from the Greek dendron (tree) and chronos (time) – had been formally introduced by Douglass just a year earlier.^[5] Over the following decade, the field flourished in the United States (and, at different times, elsewhere[6]). Researchers expanded tree-ring chronologies and applied them to archaeology, climatology and forestry. The rapid growth of the discipline in the USA only slowed as research priorities shifted during the Second World War.[7] By that point, however, the technique had already transformed several scientific disciplines. Even today, dendrochronology remains one of the most accurate dating methods available.[8]

Universal chronology

Dendrochronology reflected modern Western understandings and organisation of time. The 19th century witnessed a dramatic expansion of temporal standardisation. Industrialisation synchronised working hours and schedules. Railroads required standardised timetables to coordinate travel. Telegraph networks enabled real-time communication across and between continents. To make this accelerated long-range travel and communication possible, states standardised time zones, aligning local clocks with global temporal frameworks. Time became precise, measurable and universal (at least on paper).[9] In this context, historians and archaeologists began striving for universal chronologies. Their goal was to align diverse temporal frameworks and forms of historical dating on a single, linear timeline. Dendrochronology offered an ideal tool for this project.

Scientific time and Indigenous histories

Tree-ring dating allowed scholars in the American Southwest to connect pre-Columbian Indigenous history to the chronology of European historiography. This process of alignment was not technical or objective; it reflected deeper assumptions about history, progress and civilisation. Despite their commitment to universal chronologies, early 20th-century scholars did not believe that all societies moved through history at the same pace. Many Western intellectuals subscribed to theories of civilisational evolution, which imagined societies progressing along a developmental path from ‘primitive’ to ‘civilised’. Western industrial societies were considered most advanced, Indigenous peoples behind. Dipesh Chakrabarty famously spoke of the ‘imaginary waiting room of history’.[10] Douglass’s writings occasionally reflected these assumptions. In 1929, he described the builders of the ancient Hopi village of Hano as ‘inseparable from modern Walpi’.[11] Dendrochronology grew out of Western epistemological traditions that privileged quantification, linear time and material evidence. For archaeologists seeking recognition, precise dating methods were invaluable. Tree rings allowed them to convert archaeological remains into the numerical data modern academic culture demanded.[12] By translating Indigenous histories into the Western chronological framework, dendrochronology implicitly privileged scientific time in understanding the past. Jonas Rüegg wrote that ‘chronological time remains just one possible rendering of the relationship between past, present, and future’.[13] Many cultures conceive of time and history differently: through cycles, world-systems, genealogical narratives and spatial metaphors, for example, rather than a sequence of years.[14] Nevertheless, ‘[s]cientific time became a measure of epistemic legitimacy that eventually disempowered socially embedded modalities of historical knowledge’.[15] Western scholars dismissed other knowledge systems.

Dating as epistemic imperialism

In the American Southwest, this dynamic directly affected Indigenous historical knowledge. Before the precision of dendrochronology, some archaeologists had relied on oral traditions to reconstruct Indigenous histories. For example, Jesse Walter Fewkes, recorded oral narratives of the Hopi in the late 19th century that described historical events such as migrations and village foundations.[16] However, the temporal structures in oral traditions rarely match Western linear chronologies. As dendrochronology emerged in the early 20th century, these differences became increasingly problematic for scholars seeking academic recognition. Fewkes’s research and his evidence, oral traditions, were dismissed as unreliable.[17] Gradually, Indigenous perspectives were discursively marginalised.[18] More than an isolated phenomenon, this was imperial policy. The second half of the 19th century and the early 20th saw the enforced 'assimilation' of Indigenous people by the U.S. government. The past, present and future of Indigenous Americans were to be incorporated in bureaucratic and scientific structures. The U.S. government forced Indigenous children into boarding schools, replaced communal ownership with individual land allotment and took control over archaeological sites.[19] Dendrochronology was embedded in these broader power structures. In the early 20th-century USA, it helped integrate Indigenous history into imperial narratives of time and progress.

Reading trees, writing histories

This epistemic imperialism expanded a particular system of knowledge that marginalises other ways of understanding the world. Tree rings may be natural phenomena, but the meanings derived from them are shaped by interpretation. Historical methods shape what can be discovered and how the past can be imagined. Archaeologists are increasingly aware of the colonial heritage of their discipline, and many try to use more inclusive, reciprocal research models. But the legacy of colonialism and its epistemologies still looms large. In 2001, Larry Zimmermann criticised that archaeologists still practiced a form of ‘scientific colonialism’, extracting research data from Indigenous communities for the colonisers’ profit in the form of scholarly output and academic recognition.[20] George Nicholas and Julie Hollowell have identified ‘lack of standing given to alternative worldviews and ways of meaning-making’ as a major impediment to a postcolonial archaeology.[21] In many Native American cultures, the past is not separate from the present; instead ‘a present past is part of daily life and experience’.[22] In a debate about the use of human remains in archaeological research, Athabascan Ernie Turner explained: ‘Human bones are [not] able to talk to the scientists and leave them information. Culture talks to us and gives us messages from the past. Spiritual communication is not a theory, it is a fact. […] I am not sure what the bones tell of the spiritual beliefs of my people’.[23] The same could be said about trees: trees don’t talk directly to scientists. Dendrochronology is part of a larger story about knowledge, power and the many ways humans make sense of the past, the present and the future. In a way, measuring tree rings tells us more about archaeologists’ scientific culture than about the historical cultures they study. The idea that archaeologists aim at describing an objective, preexisting, completed truth, which is deeply rooted in Western ontology, is yet another instance of epistemic violence. As Zimmerman explained: The past lives in the present for Native American people and does not exist as a separate entity. When archaeologists state that the past is gone, extinct, or lost unless archaeology is done, they send a strong message that Native American people themselves are extinct. Acceptance of the past as archaeologists view it would actually destroy the Native American present.[24] However, attending to Indigenous culture, as Turner suggested, could help us re-read trees and thus re-write history. Not only do many trees have spiritual meaning for the Hopi,[25] but, structurally, trees are also a closer reflection of Indigenous concepts of the past, present and future than of Western concepts of history. A tree’s rings are its present past, not past and dead, but inseparable, living parts of its daily life.

[Published 15.9.2026 
temporal dis:connectivity is a blog series that explores how concepts and experiences of time shape global processes across time and space. In this series, scholars from different disciplines ask what attention to temporality can reveal about globalisation, historical change, and the ways societies imagine the past, present, and future.
For the previous entry in this series on temporal dis:connectivity, click here. To read the introduction to the series, click here.]

[1] Stephen E. Nash, Time, Trees, and Prehistory: Tree-Ring Dating and the Development of North American Archaeology, 1914–1950 (Provo: University of Utah Press, 1999). [2] Hans Hermann Rump, Bäume und Zeiten: Eine Geschichte der Jahrringforschung (Berlin: Springer, 2018), 105. [3] Nash, Time, Trees, and Prehistory, ch. 1. [4] Andrew E. Douglass, 'The Secret of the Southwest Solved by Talkative Tree Rings', The National Geographic Magazine  56, 1929. [5] Andrew E. Douglass, Climactic Cycles and Tree Growth: A Study of the Annual Rings of Trees in Relation to Climate and Solar Activity, The Carnegie Institution (Washington, D.C., 1928), 5. [6] See, for example, Staffan Bergwik, 'Synchronizing Nature and Culture: Mediating Time in Geochronology and Dendrochronology, 1900–1945', in Time and the World: Interdisciplinary Studies in Cultural Transformations, ed. Anders Ekström and Staffan Bergwik (New York: Berghahn, 2022); Linlin Gao et al., 'China's growing relevance in dendrochronology and paleoclimatology', npj Climate Action 4, no. 83 (2025). doi.org/10.1038/s44168-025-00294-7. [7] Nash, Time, Trees, and Prehistory, 10. [8] Nash, Time, Trees, and Prehistory, 10. [9] Andreas Eckert, 'Zeit, Arbeit und die Konstruktion von Differenz: Über die koloniale Ordnung in Afrika', Comparativ 10, no. 3 (2000). ; On Barak, On Time: Technology and Temporality in Modern Egypt (Berkeley: University of California Press, 2013); Vanessa Ogle, The Global Transformation of Time, 1870-1950 (Cambridge, USA: Harvard University Press, 2015); Sebastian Conrad, '"Nothing is the Way it Should Be": Global Transformations of the Time Regime in the Nineteenth Century', Modern Intellectural History 15, no. 3 (2018). doi:10.1017/S1479244316000391. [10] Dipesh Chakrabarty, Provincializing Europe: Postcolonial Thought and Historical Difference (Princeton: Princeton University Press, 2008), 8. [11] Douglass, 'The Secret of the Southwest', 744n. [12] Jürgen Osterhammel, The Transformation of the World: A Global History of the Nineteenth Century, trans. Patrick Camiller (Princeton: Princeton University Press, 2014), 780. [13] Jonas Rüegg, 'Oceanic Knowledge and National Space-Time in Pacific History', Verge: Studies in Global Asias 10, no. 2 (2024): 111. doi.org/10.1353/VRG.2024.A934657. Emphasis added. [14] On the Hopi concept of history, see Maren P. Hopkins et al., 'Hopi Perspectives on History', in Becoming Hopi, ed. Wesley Bernardini et al. (Tucson: University of Arizona Press, 2021). [15] Rüegg, 'Oceanic Knowledge', 111. [16] Wesley Bernardini and Leigh Kuwanwisiwma, 'A History of Anthropological Research on the Hopi Mesas', in Becoming Hopi, ed. Wesley Bernardini et al. (Tucson: University of Arizona Press, 2021), 81n. [17] Bernardini and Kuwanwisiwma, 'A History of Anthropological Research', 81n. [18] Bernardini and Kuwanwisiwma, 'A History of Anthropological Research', 80n. [19] Saul L. Hedquist et al., 'A Hopi Atlas', in Becoming Hopi, ed. Wesley Bernardini et al. (Tucson: University of Arizona Press, 2021), 57n; Bernardini and Kuwanwisiwma, 'A History of Anthropological Research', 83; Tim Holm, The Great Confusion in Indian Affairs: Native Americans & Whites in the Progressive Era (Austin: University of Texas Press, 2005), ch. 1. [20] Larry J. Zimmerman, 'Usurping Native American Voice', in The Future of the Past: Archaeologists, Native Americans, and Repatriation, ed. Tamara Bray (New York: Garland Publishing, 2001), 169. [21] George Nicholas and Julie Hollowell, 'Ethical Challenges to a Postcolonial Archaeology: The Legacy of Scientific Colonialism', in Archaeology and Capitalism: From Ethics to Politics, ed. Yannis Hamilakis and Philip Duke (Abingdon: Routledge, 2007), 63. [22] Zimmerman, 'Usurping Native American Voice', 173. [23] Patricia J. Carmack, 'The Study of Ancient Human Skeletal Remains in Iowa', Iowa Archaeological Society Newsletter 111 (1984): 8.  From the context, it is clear that, without the added not, Turner was either misquoted or misspoke, which is also supported by Zimmerman, 'Usurping Native American Voice', 173. [24] Zimmerman, 'Usurping Native American Voice', 175. [25] Hedquist et al., 'A Hopi Atlas'.

bibliography

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