Weather, insects put oaks under the gun
Sep 11, 2007 4:18 PM
Unless adequate rain comes soon, Arkansas’ oaks may be headed for trouble.
“Trees that were stressed by the freeze, then the oak caterpillars, and now drought, might be too weak to withstand insect and disease attacks,” said Tamara Walkingstick, a forester for the University of Arkansas (UA) Cooperative Extension Service. “This sets up perfect conditions for what we call, for lack of a better phrase, ‘oak decline,’ and that in turn, sets up good conditions for another red oak borer outbreak.”
An outbreak in 1999 killed some 20,000 acres of Arkansas woodlands. The last major outbreak in Arkansas was in 2004. That year, Fred Stephens, UA entomology chair, and other colleagues worked with graduate students to study the problem.
Where outbreaks of the borer in the 1970s showed 72 borers per tree, the 2004 outbreak saw counts as high as 4,200 per tree. Borers can girdle trees, killing them.
“While many mature red and black oaks can handle a handful of these pests, a mass attack can be fatal,” Walkingstick said.
The frostbitten oaks also produce fewer acorns, a staple food for deer. That has some concerned about the fall deer-hunting season.
“There are not as many acorns around and we really do expect it to affect the deer in a negative way,” said Keith Stephens of the Arkansas Game and Fish Commission. “We won’t know the full effect on deer numbers until we get some of the harvest reports back. We expect it to be down.”
With acres of stressed trees, timberland owners will need to pay special attention to their land this fall, Walkingstick said. “They need to manage their forest by thinning — thereby reducing competition, getting the dead, weakened and dying trees out of the stand, and in some cases, promoting the right tree for the right place.”
The extended period of hot, dry weather raises other concerns for the state’s forests. As of Aug. 28, 59 of Arkansas’ 75 counties were under burn bans and the Arkansas Forestry Commission said the wildfire danger was high in 47 counties. The remaining counties were in moderate danger.
For those with homes in the urban-wildlife interface, Walkingstick recommends the following actions:
• Clear any dry, dead foliage next to your house.
• Maintain a well-cut lawn or yard in a 30 ft. perimeter.
• Cut out dead branches hanging into your safety zone.
• Water any plants next to your house.
For more information on managing tree stands, visit www.uaex.edu. A publication on red oak borers can be found at http://www.uaex.edu/Other_Areas/publications/PDF/FSA-7055.pdf. Information on keeping your home safe in the urban-wildlife interface can be found at: http://www.arhomeandgarden.org/your_home/Fire_Safety/firewise.htm. For those considering prescribed burns, information is available at http://www.uaex.edu/Other_Areas/publications/PDF/FSA-5009.pdf.
Deer hunting information is available at http://www.agfc.com.
