δ13Cp Values from Radiocarbon-Dated Plant Matter as an Important but Underexploited Resource for Terrestrial Paleoclimate Analysis and Archaeology

Abstract

Variation in stable carbon isotope ratios in C 3 plants can be influenced by climatic and environmental factors. For archaeologists, who regularly collect the measured values of these data as a part of the radiocarbon date reporting process, there is promise in using these data to create a local record of paleoclimatic change relevant to their study areas. Plant δ 13 C can be expressed as Δ 13 C values (carbon isotopic discrimination) that can be used in modern experimental studies for stronger paleoclimatic/paleoenvironmental interpretations. As values of Δ 13 C vary in different species, taxonomic information is necessary for interpretation. In the present study, a record of Irish oak δ 13 C data are used to construct a local climate history for Ireland. Wetter periods in Ireland inferred from δ 13 C data correspond to warmer Northern Hemisphere temperatures, in agreement with climate models. Values of δ 13 C from other species are used to illustrate the importance of using data from taxa with known relationships between climate and stable carbon isotope fractionation. © 2013 by the Arizona Board of Regents on behalf of the University of Arizona.