MONTPELIER, Vt. — The very disease that has decimated millions of American elms in the U.S. is now being used to bring the iconic trees back.
Scientists with the Forest Service and The Nature Conservancy Vermont spent the summer injecting 6,000 young elm trees with Dutch elm disease spores to test their resistance to the disease. Because they have a huge impact on the hydrology of their surrounding ecosystems, said Kathleen Knight, a research ecologist with the Forest Service based in Ohio, one of the reasons protecting American elm trees is so important is.
The trees are especially important in wet forest areas, Knight said. They tolerate flooding, they can live through the cold winters of the North, and they have the ability to act like a sponge after rainfall and help prevent flooding that can be catastrophic to river systems, she said. In Vermont, Leila Wilson, a research ecologist with the U.S. Forest Service, is one of the scientists leading an effort to beat Dutch elm disease, which has killed tens of millions of elm trees over the last century. That is especially important in the era of climate change , when unpredictable weather and periods of flooding and drought can impact forests.
The disease is a key reason towering elm trees of more than 70 feet are less common in New England today than they were generations ago. The survivors will be sent to a breeding program with a goal of growing the genetic diversity of disease-tolerant elm trees. They will one day be used for restoration in forests, riverbanks and backyards. The young elms were bred from a group of a few dozen trees in the Northeast that have survived Dutch elm disease, which is a fungus that arrived in the U.S. a little less than a century ago. The fungus, spread by bark beetles, stops trees from being able to drink water, which makes them starve.
