VERMONT — Scientists with the U.S. Forest Service and The Nature Conservancy Vermont injected 6,000 young American elm trees with Dutch elm disease spores during the summer to test their resistance. Surviving trees from the resistance test will be sent to a breeding program to increase the genetic diversity of disease-tolerant elm trees.

The young elms tested were bred from a group of a few dozen trees in the Northeast that survived Dutch elm disease. Leila Wilson is a research ecologist with the U.S. Forest Service leading efforts to combat Dutch elm disease in Vermont. She said the agency would place the propagated trees into a seed orchard for about 15 years until they produce seeds for restoration. "We will put those newly propagated trees into a seed orchard, basically just a big fenced area, will grow and love those trees for about 15 or so years, at which point they should produce seeds, and that seed can be used for restoration." Wilson said.

Dutch elm disease is a fungus spread by bark beetles that prevents trees from absorbing water. The pathogen arrived in the U.S. less than a century ago and has killed tens of millions of elm trees. Gus Goodwin is a senior conservation planner for The Nature Conservancy.

He noted the emotional impact of the tree's decline on communities. "And what's missing is the big trees. A lot of people remember losing the elm. From their childhood home, their school yard. There's this kind of gravitational pull toward the elm and its loss." Goodwin said.

Joseph Ferris is an arborist in Montpelier, Vermont. He described the project as a reminder of potential for urban forestry. "It’s a really lovely reminder of what’s possible for urban trees." Ferris said.

He added that the work offers optimism given widespread forest damage. "It’s a ray of hope that is hard to feel when we’re walking through a forest and seeing all these infestations and damage. I would love to see American elm resistant, available not for just our urban plantings but restoring plantings along our streets and along our riverbanks, and just boosting the regional genetic resistance." Ferris said.