Abstract
Oak decline is a complex disease resulting in dieback and mortality of oaks. A number of factors are involved and can be classified as predisposing, inciting, or contributing, according to their roles. Decline events have been noted repeatedly during the past century in the eastern U.S. A severe episode of oak decline is occurring in the Interior Highlands region of Arkansas and Missouri. It includes an unprecedented epidemic of red oak borer (
Enaphalodes rufulus Haldeman). Mortality and dieback of northern red, (
Quercus rubra L.), black, (
Q. velutina Lam.), scarlet (
Q. coccinea Muenchh.) and southern red (
Q. falcate Michx.) oaks on thousands of acres of Interior Highland forest became evident in 1999 following 2 years of severe regional drought. A third year of drought in 2000 greatly exacerbated the problem and mortality and dieback have continued through 2002. Aerial sketch-map surveys of portions of the Ozark National Forest in Arkansas estimated that up to 300,000 acres are severely affected. Data from ground evaluations during 1999-2000 on the Ozark and Mark Twain National Forests (Missouri) showed an average of 15-28 percent of red oak basal area per acre is dead in affected stands. An additional 2-14 percent had severe dieback. Data from 2000 and 2002 plot re-measurements on the Ozark National Forest showed that mortality and dieback continued, especially in red oaks where an additional 16-20 percent of basal area per acre died over three years. However, many stands with high basal areas of red oaks have experienced nearly 100 percent mortality. Red oak borer attacks were noted only on red oak species. Greater than 10 old and new red oak borer attacks on the lower bole were noted on over 18 and 23 percent, respectively, of red oak basal area per acre in damaged stands on the Ozark National Forest in 1999. On the Mark Twain National Forest in 2000, 54 percent of the red oak basal area per acre had greater than 10 attacks.
Parent Publication
Citation
Starkey, Dale A.; Oliveria, Forrest; Mangini, Alexander; Mielke, Manfred. 2004. Oak Decline and Red Oak Borer in the Interior Highlands of Arkansas an Missouri: Natural Phenomena, Severe Occurrences. Gen. Tech. Rep. SRS-73. Asheville, NC: U.S. Department of Agriculture, Forest Service, Southern Research Station. pp. 217-222
