WHAT'S NEW WITH OAK DECLINE?

Oak decline is a complex condition caused by many factors, including predisposing conditions, inciting factors, and contributing secondary insects and diseases.  The predisposing conditions in the Central states are often relatively old age, shallow, rocky soils, and previous droughts.  The inciting conditions for the current event include severe drought and repeated defoliation by insects.  The secondary agents commonly include red oak borer, carpenterworm, two-lined chestnut borer, armillaria root disease and hypoxylon canker.  The latest developments in oak decline include:

• A conservative estimate is that 15-20% of black and scarlet oak stands in Missouri are showing severe decline.  On the Mark Twain National Forests alone, 500,000 acres have moderate to severe decline.

• The Mark Twain National Forest developed guidelines for marking hazard trees along forest roads and in recreational areas.  For more information on these guidelines, contact Ross Melick (rmelick@fs.fed.us) or Donald E. (Pepper) Martin (demartin@fs.fed.us) on the Mark Twain National Forest, or Keith Moser (MoserW@mail.conservation.state.mo.us) with the Missouri Department of Conservation.

• This spring, high levels of mortality the red oak borer larvae have been observed in Missouri.  The impact this may have on emergence of breeding adults in 2003 is unknown.

• A feature article on oak decline just came out in the July issue of the Missouri Conservationist. 

Other information on oak decline can be found on the www at:

• www.fs.fed.us/r9/marktwain/Oak_decline/red_oak_borer.pdf

• www.fs.fed.us/r9/marktwain/news_releases/oak_decline.htm