Abstract:
I explored the relationship between inter-annual tree-ring anatomical variability of overcup oak (Quercus lyrata) and river flooding at a floodplain forest site near the confluence of the White River and Mississippi River, developing chronologies of anatomical variability from quantitative measurement series and also from the visual identification of presence or absence of “flood-ring” anatomical anomalies. A chronology developed from measured widths of the first rank of earlywood vessels (VR1W) in each growth increment displayed a strong signal related to spring river levels, and a VR1W-based model of spring river levels explains 37 percent of the variance of the 67 years of mean March-April-May stage height with which it was calibrated. The flood-related signal present in the VR1W chronology provides quantitative evidence supporting the continued study of past floods using tree rings, but does not capture relative magnitude of floods better than a chronology of flood response based on visual identification of flood-ring anatomical anomalies. Further investigation of the tree-ring flood record necessitates the development of chronologies from carefully selected sites, as well as continued exploration of methods of quantifying anatomical variability.
