Advancing annually resolved oxygen isotope dendrochronology to overcome wood-dating limitations in the Euro-Atlantic region

Stable oxygen isotope dendrochronology has emerged as a ground-breaking technique for dating historic timbers when conventional tree-ring-width dendrochronology falls short. In the Euro-Atlantic region, thousands of timbers in historic buildings and archaeological sites from the Late Medieval and Early modern periods contain few tree rings or exhibit complacent growth (i.e., minimal year-to-year variation), making them undatable with conventional ring-width dendrochronology. Here, we present a 300-year-long annually-resolved δ ¹⁸ O reference chronology for the Eastern Netherlands-Northwest Germany region (TWR δ ¹⁸ O), covering the period 1300–1600 CE. We explore its correlations with other European δ ¹⁸ O chronologies, and its potential for dating short and complacent tree-ring series. We found that the TWR δ ¹⁸ O chronology exhibits strong coherence with independent δ ¹⁸ O records from Belgium and the UK, and weaker correlations with French and more continental chronologies. Our results demonstrate that δ ¹⁸ O dendrochronology can successfully date single timbers with as few as 30 rings when a local reference δ ¹⁸ O chronology is available. In the absence of such data, combining δ ¹⁸ O series from 3–5 coeval samples and extending the temporal coverage improves dating success through correlations with regional chronologies. These findings provide guidance for sampling strategies and the development of δ ¹⁸ O chronologies in the Euro-Atlantic region. The dating of currently undatable samples and their integration into dendrochronological repositories will enable a more accurate reconstruction and interpretation of past construction activities, timber trade, and forest management practices, ultimately transforming our understanding of post-medieval timber use and environmental history.