Scientists seek odds-defying ash trees
Researchers have found survivors in areas of fatal beetle infestations
10/20/2014Federal scientists now believe there are a few extra hardy ash trees out in nature that have — for reasons unknown — defied the odds and held up against the highly destructive, green metallic beetle from China known as the emerald ash borer.
They want the public’s help in finding those “survivor” trees — and are starting their research in seven northwest Ohio counties and 10 southeast Michigan counties.
Residents from Lucas, Fulton, Ottawa, Wood, Henry, Defiance, and Williams counties are asked to visit nrs.fs.fed.us/ SurvivorAsh and describe the whereabouts of ash trees they believe are surviving in infested areas that haven’t been treated with insecticides. Same goes for residents of Monroe, Lenawee, and Hillsdale counties, as well as Wayne, Macomb, Jackson, Washtenaw, Ingham, Livingston, and Oakland counties.
Ash trees used for landscaping planned subdivisions or office complexes, for example, may have been treated with insecticides. So might a private homeowner’s favorite ash tree in their front yards or backyards.
Those aren’t what scientists are seeking.
They’re looking for those rarities out in the wild, such as any surviving ash trees that hikers and birders might pass along trails in the woods.
“They just want to understand the mechanism,” said Jane Hodgins, spokesman for the U.S. Forest Service’s Northern Research Station in Minnesota.
There were an estimated 10 billion ash trees across North America before emerald ash borers were accidentally brought into the United States via shipping crates, possibly as far back as the 1990s. They first established themselves in southeast Michigan’s Canton Township, a Detroit suburb near Livonia, before fanning across the continent like wildfire. By the time they were discovered in 2002, it was too late. They were found in Ohio in 2003.
It’s been an uphill battle since, with U.S. and Canadian officials creating quarantines, limiting movement of ash firewood, and taking down large swaths of healthy ash trees in hopes of cutting the pest off from its only known source of food, ash trees.
The worst fears of forestry experts has been slowly played out. The infestation has spread to numerous states, never being fully contained.
The Northern Research Station is one of seven across the United States operated by the Forest Service. It serves 20 states from Maine to Minnesota and Missouri to Maryland.
The project it is undertaking is rooted in northwest Ohio.
A few years ago, as the USDA explains in a news release, Kathleen Knight, one of the station’s scientists, was leaving Oak Openings Metropark when she found — to her amazement — one perfectly healthy ash trees amid dozens of sick or dead ones she had been monitoring.
That tree, which is near Swanton, inspired Ms. Knight and her colleague, Jennifer Koch, a research biologist at the Northern Research Station, to begin their investigation into the hows and whys that a small percentage of ash trees appear to have a chance of survival.
“To understand the mechanisms of resistance, we need to study more than just a few survivors,” Ms. Knight was quoted in the release as saying.
“We need to be able to look at different species as well as genetic diversity within the same species.”
The two scientists are starting in this area because it was Ground Zero for the emerald ash borer infestation.
They don’t want to skew the study results with trees that aren’t true survivors or ones just lucky enough not to be infested yet.
They eventually expect to expand the study to other areas.
Small limbs and other cuttings will be taken from trees that become part of the study — small enough not to pose a risk to the host trees.
The cuttings will be grown into little offspring trees in greenhouses.
Eventually, ash borer eggs will be placed on those lab-grown trees for experiments to be done.
Contact Tom Henry at: thenry@theblade.com, 419-724-6079, or via Twitter @ecowriterohio.