The Gazette offers audio versions of articles using Instaread. Some words may be mispronounced.

AMANA — Despite deploying thousands of tests and running samples, researchers still haven’t determined why so many white oak trees across Iowa have died.

Tivon Feeley, forest health program leader with the Iowa Department of Natural Resources, said although Iowa researchers have been “casting a broad net” of tests to help determine what is causing the decline, he said it will likely be another two years before researchers can come to a conclusion.

“We’re running endless tests,” Feeley said, adding that he and his team at the DNR have conducted tests on close to 6,000 samples of Iowa oak trees looking for oak wilt — a fatal disease caused by a fungus that blocks the tree's water-conducting s

See Full Page