EXTENDING DROUGHT-SENSITIVE OAK TREE RING CHRONOLOGIES BY DATING HISTORICAL STRUCTURES IN NORTHEASTERN OHIO

Tree-ring series developed from old growth oak forests in Northeast Ohio are sensitive records of past moisture variability and have been used together with a larger network of chronologies to reconstruct drought on a continental scale. Living ring-width oak chronologies are typically 250-350 year long and are now being extended with ring records extracted from beams of historical structures. For example, crossdating local timbers from structures extends the chronology of Northeast Ohio back into the 16th century as well as providing calendar cut dates on the beams.

In addition to their utility in dating historical structures, tree ring chronologies are being used to reconstruct summer precipitation and streamflow. Five oak series from living moisture-sensitive, ring-width chronologies in Northeast Ohio together explain 34% of the variation in the June and July total precipitation when calibrated with local records over a common interval of 96 years. Similarly, August streamflow from the Killbuck Creek correlate at 0.42 with ring-widths (N=72 years) and with an increased sample base has a strong potential of reconstructing stream discharge. These ongoing efforts to extend and fill in the network of oak chronologies will contribute to large-scale modeling of drought variability for North America and to reconstructions of local hydrometeorological variables back several hundred years in Northeast Ohio.