COLO — More than a decade into a mysterious epidemic killing off white oak trees, Iowa foresters hope a new test kit will help them quickly screen trees in the field for half the cost of laboratory tests.

Inspired by COVID-19 rapid tests, a Minnesota startup developed a kit that amplifies the DNA of a fungus spreading among oaks weakened by drought. The Iowa Department of Natural Resources hopes to use information gathered from these kits to isolate infected trees and protect others.

“A lot of people are concerned about this white oak decline,” said Tivon Feeley, Forest Health Program leader for the Iowa DNR. Foresters want to know whether they should replant white oaks or choose other species. “Right now, I can’t tell them. (But) this test gives us a lot of tools we can start using.”

Background

Around 2010, foresters across the Midwest started noticing centuries-old white oak trees dying off in just one season and didn’t know why. Oak wilt, a fungal disease spread by insects or through the root systems of infected trees, was a possible culprit, but most foresters hadn’t seen it be so fast or so deadly.

“With this oak decline, we have two to three dead trees almost every other acre,” Amana Society Forester Tim Krauss said in October 2022. “We have to harvest the dead trees because we only have a year until they are no good. We can make our budget by just cutting dead trees. The downside is, they are not coming back.”

When 200-year-old and 300-year-old giants are felled, increased sunlight on the forest floor causes an explosion of invasive species and less-desirable trees, including hackberry and elm, Krauss said.

Climate change has played a role in the rapid decline of white oaks, with drought making the trees more vulnerable to disease or pests.

The U.S. Forest Service and the Canadian Council of Forest Ministers planned a pilot project with a new test kit to quickly determine if a tree has oak wilt, but efforts to develop the kits at the University of Toronto fell through in 2023.

What’s happened since

Abdennour Abbas, a professor of nanotechnology at the University of Minnesota, stepped up in 2023 with PureBioX, a St. Paul, Minn., startup that develops rapid tests for use in health care, pharmaceutical, food and agricultural industries.

“The regular test is a cell culture and it takes a very long time,” said Anil Meher, a PureBioX analytical chemist who last week visited Iowa for a trial of the oak wilt test kits at Hickory Grove Park near Colo, in Story County.

When plant diagnostic laboratories test trees for oak wilt, the results can take two weeks to two months and cost $70 to $300, the Iowa DNR’s Feeley said. PureBioX’s test kits take one hour and cost about $30 each.

“It’s quite simple so you can do it in the field setting,” Meher said.

Mark Runkel, an Iowa DNR forest health technician, and John Mullen, a GIS analyst for the department, walked out into a stand of trees at Hickory Grove to look for white oaks with signs of oak wilt. The outer leaves may turn brown, while the veins stay green. And when a branch of an infected tree is removed, the cut ends smell like fermented fruit.

From each tree, they gathered a cluster of leaves, a branch and a 3-inch trunk core. If the tests of leaves are effective in determining infection, future tests won’t require branches or trunk cores.

Mullen marked the locations of the trees in a tablet and gave each a unique ID. Mapping the infected trees is an early step to determine how oak wilt might be spreading.

Meher and Feeley put each sample into a tube with chemicals that break down the tree matter. Meher extracted the DNA and put it into a tiny vial, which is heated on a portable pad to amplify the DNA. If the Bretiella fagacearum fungus, which causes oak wilt, is present, the liquid will turn yellow. If the fungus is not present, the liquid turns pink.

If foresters find isolated trees with oak wilt, they could spray herbicide on those trees in hopes of halting the transmission through underground root systems, Feeley said.

The team plans to test trees in the Amana Society’s 7,000-acre timber, in Marshall County, in the Loess Hills in Western Iowa and in the Des Moines area. They also are putting out insect traps in forests with oak wilt to see what kinds of bugs might be carrying the fungus. Results of these studies will go into the 2024 Forest Health report.

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As West Des Moines Valley’s star distance runner Addison Dorenkamp made her way to Drake Stadium for the start of her final state track and field meet Thursday, she began to worry about the heat projected in the forecast.

Her mom, Jan Dorenkamp, saw the irony in her daughter’s concern.

“You better get used to it,” Jan Dorenkamp told Addison. “That’s what it is going to be like down south.”

The meet served as a teaser for what’s to come for Addison Doreknamp when she heads to the University of Alabama to continue her distance-running career. Hot temperatures and humidity will be the norm, most days a lot worse than what she faced on the Blue Oval.

The early results, as usual, were pretty good for the senior as she shook off the concern and secured a 3000-meter title Thursday morning.

As she came off the track, she reached for a water cup and dumped it over her head for instant relief from the heat.

“I was kind of dying,” Dorenkamp joked. “It was the one thing I thought I could do to cool myself down.”

She returned to the meet on Saturday for her final high school event, the 1500. Temperatures hovered in the upper-80s in Des Moines with a much hotter surface on the track.

She refused to be denied on this special day, securing the all-time Iowa record with a 4:25.32. That was over an entire second faster than Sioux City East’s Shelby Houlihan in 2010 (4:26.39).

As public address announcer Mike Jay serenaded Dorenkamp for a special career, he revealed to the crowd that it was Dorenkamp’s 18th birthday. How Jay knew that information was a surprise to her, after not telling many people. She planned to attend and celebrate her fellow seniors at their graduation parties following her state title rather than celebrate her birthday.

As humble as she was, she couldn’t help but express her excitement after that type of performance.

“It’s probably the greatest birthday present I’ve ever gotten,” Dorenkamp said.

Anyone in attendance at the state track meet saw how impressive Dorenkamp’s race was. As Dorenkamp was approaching the record, she said she felt her eyesight go just about black as she ran the final 100 meters in the sweltering heat.

That moment, she proved to herself that heat wouldn’t be too much of a problem when she heads off to college.

“It’s nice to know that I’m not a complete wimp,” Dorenkamp joked.

Dorenkamp ends her career with eight state championships, two in cross country and six in track. In cross country, she holds the third-fastest time in Iowa history at 17:40.1. For track, she swept the distance events three consecutive years and holds the 3000-meter record with her time of 9:23.6 at this year’s Drake Relays. She also holds Drake Relays records in the 1500 and 3000, which she set in April.

Every state title was precious for the Valley senior. However, as she reflects upon one of the most dominant legacies that the Iowa high school community has seen in distance running, she just hopes the next generation is better than her.

“Hopefully I was able to inspire younger athletes along the way who one day will break my records,” Dorenkamp said.

Eli McKown covers high school sports and wrestling for the Des Moines Register. Contact him at Emckown@gannett.com. Follow him on Twitter at @EMcKown23