The Hohenheim tree-ring archive is one of Europe’s most important dendrochronological collections. With samples from about 35,000 well‑preserved trees – mostly oak and pine – packed in ~3,000 crates, it provides a continuous, absolutely dated chronology from 10,460 BC to today (12,460 consecutive growth rings). The series underpins today’s IntCal20 radiocarbon calibration and is a cornerstone for archaeological dating and high‑resolution climate research.
Beginning
The Austrian botanist Bruno Huber started the collection in the 1940s at the University of Munich. His former assistant, Prof. Dr. Bernd Becker brought the archive to the University of Hohenheim in the 1970s. During a large variety of projects sub‑fossil river oaks, archaeological timbers and living‑tree cores from across Central Europe were collected – mainly the regions of southern Germany along the rivers Main and Danube. By systematically measuring and cross‑dating ring widths, Becker’s team produced the first continuous Late‑Glacial/Holocene master curve.
The collection in numbers
- Species: Primarily Quercus robur/petraea and Pinus sylvestris
- Sample size: discs up to 1 m in diameter, slices a few cm thick, drill core samples
- Measurement precision: annual rings scanned and measured to 0.01 mm (1/100 mm) accuracy
- Supporting data: original field logs, index cards, photographs and legacy digital files now migrated into an SQL archive
- ~15,500 further dendrochronological measurements (without physical samples in the archive)
- Overall, around ~24,200 dated measurements
A new home in Mannheim
A staged relocation, funded by the Klaus Tschira Foundation, ran from 2015 to 2020. The first 300 crates (> 5 t) arrived in May 2015; the last truckloads were unloaded by late 2020. Climate‑stabilized storage, digital inventory management and photo documentations are in place, and public access to the digital catalogue is planned in the future.
Why the archive matters
- Absolute dendrochronological dating of archaeological wood using the archives long chronologies
- Climate proxies: ring widths and densities trace temperature, rainfall and ecological stress back to the Younger Dryas; using stable isotopes (δ¹³C, δ¹⁸O, δ²H) to generate annually resolved climate reconstructions spanning the full 12,000-year chronology; the archive’s depth and ≈ 44,000 specimens provide ample material for highly replicated, statistically robust series.
- Radiocarbon calibration: the 14C data measured on the wood samples remain the backbone of the Northern‑Hemisphere IntCal20 dataset. Current and future research projects use and will use wood material from the archive to extend the calibration curve with high temporal resolution.
- Cross‑disciplinary infrastructure: the archive is linked with CEZA’s radiocarbon and stable-isotope laboratories, enabling current and future cross-disciplinary analyses
Collaborate with us
We invite researchers to explore the archive’s potential. Whether your focus is:
- Dendrochronology
- Palaeoclimate reconstruction
- Radiocarbon calibration
- Methodological advances in tree‑ring science
- Art history or monument research
We would be happy to discuss possible collaborations.
Looking forward, we aim to expand the archive through the collection of new wood samples from relevant contexts such as gravel pits and archaeological sites. We are actively looking for collaborators to join us in these efforts.
We are also open to providing a secure and research-oriented home for other dendrochronological archives that may need to be relocated. If you’re interested in working with the archive — whether for a collaborative research project or sample contribution — get in touch with us. We’d be glad to explore possibilities together.
Do you need further information or do you have any questions?
Please feel free to contact us.