Stable isotopes in tree rings for dendrochronology and climate change research

Tree-ring dating or dendrochronology, is unique in its ability to assign calendar dates to timber artefacts. Through careful statistical matching of ring width patterns, dendrochronology has revolutionised science-based archaeology and palaeoclimatology, however its application is limited by wood species, provenance and segment-length.

A new dating technique; isotope-dendrochronology, combining multiple isotopic indicators and tree-ring widths has been developed to provide precise dating with quantified statistical confidence. As stable isotopes exhibit higher spatio-temporal signal strength and inter-species coherence than ring width, there is significant potential to revolutionise the dating of difficult samples: for example, where species, segment-length or chronology replication make conventional dendrochronology challenging.

 

In addition to precision dating, the stable isotopes in tree rings preserve a strong environmental signal and may be used to reconstruct past climates and to study tree response to environmental change. The carbon, oxygen and hydrogen isotopes in the tree ring cellulose relates closely to the carbon dioxide and water sampled by the tree during photosynthesis, which in turn relate to climatic factors such as sunshine, temperature, precipitation and humidity. The method works well in regions where tree growth is not strongly controlled by climate, but it can be applied globally, and integrated with other tree-ring data using a multi-parameter approach.

The interdisciplinary research team is led by Prof. Neil Loader (Swansea University) with researchers from Oxford and Helsinki. Please contact us if you would like further information on using tree-ring isotopes for precision dating or exploring the climate of the past.

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