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Research Highlights

Individual Highlight

A native fungus takes on an exotic and aggressive tree species

Photo of Dead and dying Ailanthus trees inoculated with biocontrol fungus. Dead and dying Ailanthus trees inoculated with biocontrol fungus. Snapshot : Working with the Wayne National Forest and the Ohio Department of Natural Resources, Forest Service scientists are studying a native fungus and finding that it kills ailanthus trees while sparing native tree species. Inoculations in research trials began in 2015 in Ohio and appear to be successful.

Principal Investigators(s) :
Rebbeck, Joanne 
Research Location : Delaware OH and throughout SE OH
Research Station : Northern Research Station (NRS)
Year : 2017
Highlight ID : 1224


Ailanthus, commonly known as tree-of-heaven but more appropriately called “stink tree” due to the pungent order of its crushed foliage, is an introduced invasive common in eastern mixed oak forests. Since it is a rapidly growing and prolific tree, it often displaces native plants and disrupts forested ecosystems. It is very challenging to control chemically because it is a prolific sprouter; however, there may be an alternative biocontrol in the near future. A native soil-borne fungus, Verticillium nonalfalfae, which was discovered in Pennsylvania by Penn State researchers, is very specific and deadly to ailanthus but not to more than 75 other woody species. In a trial on the Wayne National Forest in Ohio, three Ohio state forests and a private, non-profit wildlife conservation center, researchers are testing the effectiveness of the fungus in killing ailanthus as well as monitoring subsequent regeneration. To date, control has been effective with no off-target effects being observed. Forest Service scientists are continuing to formally study nontarget effects before large-scale releases into forest environments begin. Scientists are also investigating ways to streamline the production of inoculum by developing improved and expedient culturing methods of fungal spores; existing production methods take three to four weeks to complete and are labor intensive.

Forest Service Partners

External Partners

  • Wayne National Forest
  • Ohio Department of Natural Resources Division of Forestry
  • Pennsylvania State University
  • The Wilds
  • West Virginia University

Program Areas