• Sampling and Precise Dating Requirements for Extracting Isotopic Records from Tree Rings

      Stockton, Charles W.; Boggess, William R.; Laboratory of Tree-Ring Research, University of Arizona; Laboratory of Tree-Ring Research, University of Arizona (American Chemical Society (Washington, D.C.), 1982)
      The use of tree-ring width series as the time control for extraction of isotope and chemical information from wood cellulose has become commonplace. However, many researchers are unaware of the need to maximize the signal in the tree-ring series by sampling from those populations that are most sensitive to past environmental conditions. The series which are most environmentally sensitive may also be the most difficult to date accurately. Therefore a sufficient number of samples must be collected to provide adequate dating control. Techniques exist that can assure precise dating of individual ring widths but they depend on adequate replication of samples. Proper site selection and dating techniques for adequate tree-ring analysis will be discussed. Examples will be cited in which necessary sampling depth and ring width analysis appear to be insufficient to justify subsequent conclusions made from the derived isotopic series.