A record of flooding on the White River, Arkansas derived from tree-ring anatomical variability and vessel width

Abstract

Tree rings preserve important records of past flooding. We present the results of an examination of inter-annual tree-ring anatomical variability and vessel width in overcup oak (Quercus lyrata) and river flooding at a bottomland hardwood forest site near the confluence of the White and Mississippi Rivers. We developed two flood chronologies based on (1) visual identification of ?flood-ring? anatomical anomalies and (2) a simple method for quantitative measurements of earlywood vessel width (VW). Using visual flood rings, we have developed a response index (RI) chronology of floods from 1780?2013 and, using the VW measurements, we have developed a quantitative reconstruction of spring river levels from 1800?2013. Both the RI and VW chronologies are strongly related to spring river flooding and indicate that major floods such as those in 1805, 1826, 1844, 1852, 1858, occurred in the period prior to the systematic collection of stage data, and that the frequency of extreme events has greatly varied over the past two centuries. These chronologies provide important new information about Lower Mississippi River flooding in past centuries, and our simple method of measuring VW is a potentially useful new approach to the development of tree-ring records of flooding.