Native Fungus vs. Non-native Invasive Tree: Study Begins at Wayne National Forest

Contact(s): Gary Chancey, Public Affairs Officer, 740-753-0862

Photo of Ailanthus TreeNELSONVILLE, Ohio – Research beginning this week on the Wayne National Forest will explore whether a native fungus can help land managers rein in an aggressive, non-native invasive tree that has been steadily encroaching on Ohio forests, particularly in the southern half of the State.

Trial sites include the Wayne National Forest, Athens Ranger District-Marietta Unit; Tar Hollow, Perry, and Blue Rock State Forests; and the Wilds a private, nonprofit wildlife conservation center in Muskingum County. Joanne Rebbeck, a USDA Forest Service Northern Research Station scientist will inoculate Ailanthus trees with Verticillium nonalfalfae (V. nonalfalfae) to evaluate how effective it might be in controlling Ailanthus. Forty trees will be inoculated with the fungus at each of the five sites.

On the particularly hard-hit Marietta Unit, almost 3,000 seed-bearing Ailanthus located through aerial surveys across 124,000 acres, which is one reason to focus the study in this area because herbicide treatments on this large a scale would be cost-prohibitive. (View Inventory Map

“Throughout Ohio, Ailanthus has the potential to replace oak and other native tree species and dramatically affect native food sources for wildlife,” said Tony Scardina, Wayne National Forest supervisor. “Research at the Wayne National Forest this summer will help assess the potential value of V. nonalfalfae as a non-chemical, sustainable means of controlling Ailanthus, which could be a first step in restoring healthy native forests.” (View Images)

Photo of Joanne RebbeckThe effect of V. nonalfalfae, often called “Ailanthus wilt,” was first documented in Pennsylvania in 2002 by Penn State researchers. Rebbeck, shown here, has studied the fungus in the lab and greenhouse and has contributed to studies showing that V. nonalfalfae does not affect over 70 species of trees and shrubs, including Ohio tree species such as ash, beech, elm, hickory, and oak.

“In addition to studying the effectiveness of V. nonalfalfae as a biological control for Ailanthus, this research will also explore how native forests respond when Ailanthus is absent,” Rebbeck said. “Do native trees regenerate, or will another invasive species replace the Ailanthus?”

Ailanthus, also known as “tree of heaven,” is a native of Taiwan and central China that was introduced to the U.S. by a gardener in Pennsylvania in 1784. The tree is a master of regeneration, growing 3 to 4 feet in its first year, producing 300,000 seeds per female tree, and spreading through root systems. Ailanthus is often found in open spaces, but is increasingly found within disturbed forest sites.

“The aggressive growth habits of Ailanthus are a threat to the biodiversity of Ohio’s forests,” said Robert Boyles, Ohio Department of Natural Resources deputy director and state forester. “The results of this research could have a significant, positive, and lasting effect on forest health throughout the state.”

Learn more about the project by downloading an educational brochure. Additional information about this project can be found online at the NRS website.

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The U.S. Forest Service is an agency of the U.S. Department of Agriculture, a mission of sustaining the health, diversity and productivity of the nation’s forests and grasslands to meet the needs of present and future generations. The Forest Service’s Eastern Region includes twenty states in the Midwest and East, stretching from Maine, to Maryland, to Missouri, to Minnesota. There are 17 national forests and one national tallgrass prairie in the Eastern Region. For more information, visit


The U.S. Forest Service manages 193 million acres of public land, provides assistance to state and private landowners, and maintains the largest forestry research organization in the world. Public lands the Forest Service manages contribute more than $13 billion to the economy each year through visitor spending alone. Those same lands provide 20 percent of the nation’s clean water supply, a value estimated at $7.2 billion per year. The agency has either a direct or indirect role in stewardship of about 80 percent of the 850 million forested acres within the U.S., of which 100 million acres are urban forests where most Americans live. For more information, visit


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