Characteristics of sites and trees affected by rapid white oak mortality as reported by forestry professionals in Missouri

by

Sharon E. Reed, James T. English, Rose Marie Muzika, John M. Kabrick, Simeon Wright

Corresponding author: SE Reed; Research scientist, University of Missouri Plant Sciences Division, Columbia MO 65211, reedsh@missouri.edu, J.T. English; Professor, University of Missouri Plant Sciences Division, Columbia MO 65211, R. M. Muzika; Professor, Department of Forestry, School of Natural Resources, Columbia MO 65211, J. M. Kabrick, Research Forester, USDA Forest Service, Northern Research Station, Columbia MO 65211, S. Wright; Forest Pathologist, Missouri Department of Conservation, Columbia MO 65211

Abstract – Quercus alba L. trees affected by rapid white oak mortality (RWOM) die abruptly after leaf-out or during late summer and are mostly located at or near the base of hills. RWOM became a concern in 2011 and 2012 and is still being reported. A survey with 24 questions about stand and site characteristics, site history, and symptoms was distributed among forestry professionals. Sixty-three reports were received. The majority of the mortality was reported in the southeastern quadrant of Missouri and nearby areas. Surveyors reported that RWOM affected Q. alba trees of all sizes but disproportionately affected larger trees in the co-dominant and dominant crown classes. Some surveyors also reported Q. stellata Wangenh. trees and trees in the red oak group dead or dying. Declining Q. alba were still present in many of the stands. Mortality was mostly associated with the lower slope and in the bottom of drainages with ephemeral or intermittent streams. No particular aspect appeared to be associated with RWOM. Descriptions of soils downloaded from the USDA-NRCS soil web mapper included mostly well drained to excessively well drained soils with gravelly or very gravelly loam, silty loam or sandy loam textures. Stands affected included those with and without active management in the past ten years. Survey results largely agree with results of a scientific study at two locations. Collection of scientific data is needed at each of the survey locations to confirm survey results and provide more detailed information about the characteristics of areas affected by RWOM.