Tree-Ring Stable Isotopes Reveal a Hydroclimate Shift in Eastern England Around 4.2 ka Ago

Abstract

Tree ring-based climate reconstructions are fundamental for high-resolution paleoclimatology, but only a few of them extend back into the mid-Holocene (8,200–4,200 years BP). Here, we present annually-resolved tree-ring stable carbon and oxygen isotopes (δ¹³C and δ¹⁸O) from subfossil yew (Taxus baccata) wood excavated in the Fenland region of eastern England. We develop an eco-physiological model to reconstruct hydroclimate variability from 5,224 to 4,813 ± 4 and 4,612–4,195 ± 6 cal. years BP. Our findings suggest that a relative sea-level rise in the North Sea, riverine flooding, and a prolonged negative phase of the North Atlantic Oscillation caused unusually wet conditions around 4,200 years ago when yew woodlands in eastern England disappeared. We expect our study to stimulate high-resolution stable isotope measurements in relict wood and encourage the integration of terrestrial and marine proxy archives to reconstruct the causes and consequences of large-scale climate variations around the still debated 4.2 ka event.