Invasive emerald ash borer hurts Michigan timber sales
by Lacee Shepard
The devastating spread of the emerald ash borer shows no sign of slowing and it is causing the pace of timber sales to quicken.
Timber sales are important for their contribution to the timber based industry as well as the welfare Michigan residents, according to the Department of Natural Resources.
Michigan started seeing an infestation of emerald ash borer in 2002, said Doug Heym, a DNR timber sales specialist. The insect is a beetle that efficiently eats the layer below bark, causing a lack of nutrients, or girdles a tree, leading to its death.
“Eggs are laid on the bark of ash trees, and when the eggs hatch the larva under the bark and they eat the cambium layer of the tree,” said Heym. “When they eat that cambium they in essence screw up the plumbing of the tree.”
Heym said that part of the timber on DNR forest land was meant to be held for sale at a later date. However the outbreak of emerald ash borer has accelerated the timetable.
“When emerald ash borer get to the stand of timber, it’s pretty lethal. In a few years almost all of your ash trees are dead,” said Heym. “We’ve had problems in contracts that we’ve already sold – trees that we sold when they were alive ended up being killed.”
The selling of timber has been accelerated in areas that were not initially planned because the trees are dying, he said.
For example, the damage on DNR land near Gaylord has spread up the salvaging process of harvesting infected trees while the Gladwin area is seeing a higher tree mortality rate, said DNR timber program management assistant Donovan Asselin.
The current infestation is causing a decrease in salvage bid sales but the DNR won’t see any noticeable decrease in sale until next year, he said
Deborah McCullough, a forest entomology professor at Michigan State University, said she doesn’t think there’s a way to eliminate emerald ash borers at this point. However, there are ways to slow down the pest.
“One of the things that a lot of money and effort is going into is biological control,” said McCullough. “Federal agencies are putting millions of dollars into rearing and releasing tiny little wasps that attack either eggs or larvae of emerald ash borer.
“The idea is that eventually, as the natural enemies become established, they will control emerald ash borer.”
Insecticides can be injected that will protect a tree for three to five years, but that’s not an economically justified option for large numbers of trees, said McCullough. The insecticides are used for ornamental trees or for just a few in people’s backyards.
Brenda Owen, executive director of Michigan Association of Timbermen,in Newberry said that there are still many areas in the southern part of the Lower Peninsula and the northern part of the Upper Peninsula that have not been infested,but it still has a negative impact on sales.
“We’ve seen changes in the way some of our members do business,” said Owen. “They may act more quickly on a sale if they know that the ash trees need to be harvested more quickly to get the best dollar value from the trees. Obviously the more infested the trees are, the more the dollar value will continue to decrease.”
If trees are infected they have between one to four years to be harvested, said Owen.