The tree crisis slowly spreads across America

Iowa DNR preparing ash counts in Seymour, Corydon and Allerton

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A middle-aged ash on the front lawn of the Corydon Bible Church just off Highway 2 begins to lose leaves from its canopy, most likely the result of infestation by the emerald ash borer. Experts say if more than 50 percent of the tree is dead, insecticide cannot save it. / Photo by Jason W. Selby

At one time, elms lined West Street in Corydon; their familiar fluted limbs rose over many homes in America. Then came Dutch elm disease.

In the Appalachian Mountains, wide swaths of hemlocks are dying, the result of a non-native invasive pest. In the Rocky Mountains, millions of pines, aspens and spruces stand dead. Hotter weather is leading to longer lifespans for insects, increasing the number of wildfires and causing more extensive periods of drought.

Some of this can be seen in Wayne County, in evergreens that grew for almost a century in Walden Park. Entire timbers of the same tree, planted as windbreaks, have died across southern Iowa.

One obvious solution is diversification of species—no longer planting one kind in the same location. It is not a cure-all.

Most of life on Earth, including the ash, is not planned in a sense human beings can conceive. It would have been difficult to predict the emerald ash borer could earn its American name. The outbreak spread westward in 2002—a road trip east through Iowa presents the devastating scene more vividly—and only a year after Wayne County’s infestation, ash limbs have been stripped of leaves and rot white along roadways and in parks, small towns and cities.

Traci Ott is an Extension Program Specialist and urban forester for Iowa State University. She works with counties for the Community Tree Steward Program.

“Green ashes versus white ashes respond differently to the emerald ash borer,” Ott said. “In the end, they all die.”

The blight’s impact on humans is difficult to determine. There have already been several deaths across infected areas from falling branches. As Lindsay Abrams writes in her 2013 article, “When Trees Die, People Die,” published in The Atlantic:

Within four years of first becoming infested, the ash trees died—over 100 million since the plague began. In some cases, their death has an immediate impact, as they fall on cars, houses and people. In the long term, their disappearance means parks and neighborhoods, once tree-lined, are now bare.

Something else, less readily apparent, may have happened as well. When the U.S. Forest Service looked at mortality rates in counties affected by the emerald ash borer, they found increased mortality rates. Specifically, more people were dying of cardiovascular and lower respiratory tract illness—the first and third most common causes of death in the U.S. As the infestation took over in each of these places, the connection to poor health strengthened.

It presents a unique challenge to Director of EMC/E911 Bill Byrns of Allerton. Through Byrns’ eyes, the lack of planning seems to have continued:

“Regarding emergency management, I don’t think there has been anything come across our emails in regard to [ash trees]. At the senior housing in Allerton, there was one still blooming really well, but the past couple weeks when the wind came up, it took the tree down due to the fact it was infested. There’s the possibility of someone getting hurt.

“Late last year, it was confirmed in Wayne County. Now, driving around, you can tell which trees are diseased.”

On the lawn of the Wayne County Courthouse, the Supervisors are attempting to save the few ashes that remain, using an insecticide that must be re-administered.

“It’s a sad deal,” Byrns said. “I hate to see trees die—I really do.”

On the campus of Iowa State University in 2010, forestry experts cut down healthy ashes. It seemed at face value like a strange measure, but these living individuals were kindling being prepared as hosts for the destruction of the entire species.

“They were taking preventative measures,” Ott said, “instead of waiting until it hit and seeing if any trees would survive.”

Scientists are collecting seeds to save the future of the ash. It might be the only way to preserve their inheritance for coming generations.

This is no small feat of chaos for a tiny, shiny green beetle from Asia.

Wayne County Assistant Engineer Dan Carpenter has cleared a few ash trees from roadways already. His mother-in-law, Linda Couchman, lives south of Sewal at the end of a drive called Ash Lane, named after her two daughters. Soon the ash trees that line it will be gone.

It will be emotional for the family to watch them fall.

“Eventually, it’s probably going to get all those,” Carpenter said. “It’s a big deal.”

An ash tree stricken by the emerald ash borer at Chris Street Memorial Park in Humeston. / Photo by Jason W. Selby

Disaster area

According to Iowa DNR’s Emma Hanigan, a state urban forester, there are more threats to native trees on the horizon. When she started her job 10 years ago, the emerald ash borer had just been discovered in Iowa in Allamakee County.

“Our main goal is to help communities prepare,” Hanigan said. “The main technical assistance we provide are plans and inventories that cover all public trees.

“In Iowa, we have an average of 17 percent canopy, so we lose all those benefits trees provide, like water and air quality, ambient temperature—trees even help mental health because they stimulate lower cortisol levels, which creates less stress. If you add all those things together, it can have a big impact on people.”

District forester Jeremy Cochran recently reached out to Corydon about performing tree inventory this summer. Last week, inventory was finished for Allerton. Seymour is on the list for next year.

“It can be devastating economically,” Hanigan said. “Most communities have to spread it out over several budget years and be careful about their management strategy because they just don’t have the funding to deal with this crisis.

“The same thing on private property. Every community has homeowners that can’t afford tree removal on their own.”

Because of the slow moving nature of the plague, disaster relief has only trickled in so far.

“It’s not overnight like a tornado, but the impact could be the same,” Hanigan said. “Arbor Day considers the emerald ash borer a disaster. In my mind, any place that’s going to lose more than 10 percent of their tree resource is a disaster area.

“The Asian long-horned beetle, if it came to Iowa, could take out a third of our canopy. It’s in the northeastern U.S. right now, and its host is the maple. There’s another insect, the spotted lanternfly, and it could take out all the crab apples and some others like cherries. So, there are definitely pests coming in the future that could greatly impact Iowa.”