Climatic information from 18O/16O analysis of cellulose, lignin and whole wood from tree rings

Abstract

MEASUREMENTS of stable isotope ratios on tree rings have proved a promising way of determinating past climate1–5. Recent discussions have centred on which component of wood provides the most reliable record6,7. We have measured the oxygen isotopic composition of cellulose, whole wood and lignin from tree rings in a white spruce (Picea glauca) which grew in the Edmonton area from 1882 to 1969. Using meteorological records we have evaluated the responses of the 18O/16O ratios of the three components of the tree rings to seasonal temperatures. Results show a high correlation between cellulose 18O/16O ratios and mean annual temperature, a poorer, though still significant correlation between whole wood 18O/16O ratios and mean annual temperature and no significant correlation between lignin 18O/16O ratios and mean annual temperature.