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You are here: NRS Home / Research Programs / Forest Disturbance Processes / Invasive Species / Emerald Ash Borer / Effects and Impacts / Effects of emerald ash borer on forest ecosystems
Emerald Ash Borer

Effects of emerald ash borer on forest ecosystems

Research Issue

[photo:] Dead ash trees create a canopy gap in a forest.Emerald ash borer (Agrilus planipennis) is a major threat to the ash species (Fraxinus spp.) in hardwood forests.  Effects of emerald ash borer may be similar to those of chestnut blight or Dutch elm disease.  As ash trees in forests die, gaps form in the forest canopy, allowing light to reach understory vegetation.  Native trees may respond and fill in the gaps.  Ash seedlings that were too small to be infested during the first “wave” of emerald ash borer may grow larger and eventually become infested.  Invasive plant species may be facilitated by the increased light levels, allowing the plants to colonize new areas, grow rapidly, and reproduce.  Native herbaceous plants may be impacted by the loss of the ash trees and the responses of other vegetation.  Soil properties may change due to the disappearance of ash, a calcium accumulator. 

 Our Research

We are studying the effects of ash mortality on native and invasive woody and herbaceous plants, understory light levels, and soil properties in monitoring plots in 254 monitoring plots in 80 forest stands in Ohio and Michigan.  Invasive plant species are already present in many of the monitoring plots, however, the cover of these species is <1% in >40% of the plots in Ohio and >70% of the plots in Michigan.  Frequently encountered invasive species in Ohio include amur honeysuckle (Lonicera maackii), garlic mustard (Alliaria petiolata), multiflora rose (Rosa multiflora).  In Michigan, frequently encountered species include multiflora rose, autumn olive (Eleagnus umbellata), glossy buckthorn (Frangula alnus), and morrow’s honeysuckle (Lonicera morrowii). 

Expected Outcomes

We will quantify wide-ranging effects of emerald ash borer on forest ecosystems.  Understanding the conditions that facilitate invasive species will assist managers in taking action to prevent the spread of invasive species in infested forests.

Research Results

Herms DA, Gandhi KJK, Cardina J, Long RP, Knight KS, Smith A, and McCullough DG. 2008. Impacts of emerald ash borer – induced gap formation on forest communities. [abstract] In: Proceedings, Emerald ash borer research and development meeting. October 23-24, 2007. Pittsburgh, PA. FHTET-2008-07. p. 10.

Knight KS, Long RP, and Rebbeck J. 2007. Predicting emerald ash borer-induced changes in forest tree species composition. In: Mastro, Victor; Lance, David; Reardon, Richard; Parra, Gregory, comps. Proceedings, Emerald ash borer and Asian longhorned beetle research and technology development meeting.  pp. 25-26. Cincinnati, OH 29 Oct. – 2 Nov. 2006. FHTET-2007-04. Morgantown, WV: U.S. Department of Agriculture, Forest Service, Forest Health    Technology Enterprise Team. Abstract.

Research Participants

Principal Investigators

Research Partners

Last Modified: 01/08/2013

About this Research Area
About Emerald Ash Borer
Selected Studies
Featured Publication

Knight KS, Long RP, and Rebbeck J. 2007. Predicting emerald ash borer-induced changes in forest tree species composition. In: Mastro, Victor; Lance, David; Reardon, Richard; Parra, Gregory, comps. Proceedings, Emerald ash borer and Asian longhorned beetle research and technology development meeting.  pp. 25-26. Cincinnati, OH 29 Oct. – 2 Nov. 2006. FHTET-2007-04. Morgantown, WV: U.S. Department of Agriculture, Forest Service, Forest Health    Technology Enterprise Team. Abstract.