Land Management to Mitigate Emerald Ash Borer Impacts

Research Issue

Swamp white oak seedlings planted in openings of blak ash.Northern Minnesota contains the largest expanse of ash-dominated forest in the country, with black ash making up 95 percent of trees in these wetland forests. The species affects nearly all aspects of ecosystem functions and is important for the regulation of water, wildlife habitat, and timber value, among other things. The invasive emerald ash borer moving into this 1.2 million acres of forest poses a potential environmental disaster. Researchers at the Northern Research Station are investigating what might happen when the emerald ash borer comes through this vast forested area and are experimenting with strategies to mitigate those effects and preserve the ecological functions of black ash wetlands in the landscape after the pest arrives.

Our Research

As the emerald ash borer approaches Minnesota’s 1.2 million acres of black ash wetlands, Northern Research Station scientists and collaborators have developed an experimental design to understand how the tree affects ecosystem functions, including hydrology, nutrient cycles, and food webs. Using different harvesting approaches, some that mimic predicted mortality rates from the emerald ash borer, as well as replanting areas with replacement tree species, researchers are gaining a better understanding of potential impacts, and how to adjust for them.   

A key finding is that hydrologic functions are closely tied to tree cover; loss of black ash without aggressive replacement with other species leads to marsh conditions. Moreover, leaves of black ash decompose faster than other species, readily becoming food for aquatic invertebrates. Conversion to replacement trees or marsh vegetation will alter food webs and the amphibian communities that depend on them. Promising replacement tree species include swamp white oak and balsam poplar; these species will maintain hydrologic function, but not aquatic food webs based on black ash leaves.  

Expected Outcomes

This research is ongoing and designed to be a long-term study. Researchers are taking regular measurements of hydrology, trees, nutrients, small mammals, birds, and amphibians and have discovered some dramatic changes already taking place. This research will help land managers better design guidelines and strategies aimed at pre-emptive management of this vast forest type in the face of these threats. This work also has serious implications for local tribes. Black ash is the only species used for Native American basket-making. With the possible future loss of this resource, there will also be a potential loss to traditional Native American culture.

Research Results

D'Amato, A.; Palik, B.; Slesak, R.; Edge, G.; Matula, C.; Bronson, D. 2018. Evaluating Adaptive Management Options for Black Ash Forests in the Face of Emerald Ash Borer Invasion. Forests. 9: 348.

Diamond, J.; McLaughlin, D.; Slesak, R.; D'Amato, A.; Palik, B. 2018. Forested versus herbaceous wetlands: Can management mitigate ecohydrologic regime shifts from invasive emerald ash borer? Journal of Environmental Management. 222: 436-446.

Looney, C.; D'Amato, A.; Palik, B.; Slesak, R. 2017. Canopy treatment influences growth of replacement tree species in Fraxinus nigra forests threatened by the emerald ash borer in Minnesota, USA. Canadian Journal of Forest Research. 47: 183-192.

Youngquist, M; Eggert, S.; D'Amato, A.; Palik, B.; Slesak, R. 2017. Potential effects of foundation species loss on wetland communities: A case study of black ash wetlands threatened by emerald ash borer. Wetlands. 37: 787-799.

Looney, Christopher E.; D'Amato, Anthony W.; Palik, Brian J.; Slesak, Robert A.; Slater, Mitchell A. 2017. The response of Fraxinus nigra forest ground-layer vegetation to emulated emerald ash borer mortality and management strategies in northern Minnesota, USA. Forest Ecology and Management. 389: 352-363. https://doi.org/10.1016/j.foreco.2016.12.028.

Looney, C.E., D’Amato, A.W., Palik, B.J., Slesak, R.A., 2015. Overstory treatment and planting season affect survival of replacement tree species in emerald ash borer threatened Fraxinus nigra forests in Minnesota, USA. Can. J. For. Res. 45: 1728–1738.

Telander, Andrew C.; Slesak, Robert A.; D'Amato, Anthony W.; Palik, Brian J.; Brooks, Kenneth N.; Lenhart, Christian F. 2015. Sap flow of black ash in wetland forests of northern Minnesota, USA: Hydrologic implications of tree mortality due to emerald ash borer. Agricultural and Forest Meteorology. 206: 4-11.

Slesak, Robert A.; Lenhart, Christian F.; Brooks, Kenneth N.; D'Amato, Anthony W.; Palik, Brian J. 2014. Water table response to harvesting and simulated emerald ash borer mortality in black ash wetlands in Minnesota, USA. Canadian Journal of Forest Research. 44(8): 961-968. https://doi.org/10.1139/cjfr-2014-0111.

Research Participants

Principal Investigators

  • Brian Palik, USDA Forest Service Northern Research Station, Research Ecologist
  • Sue Eggert, USDA Forest Service Northern Research Station, Research Aquatic Ecologist
  • Randy Kolka, USDA Forest Service Northern Research Station, Research Soil Scientist

Research Partners

  • Chippewa National Forest
  • Anthony D’Amato, University of Vermont Rubenstein School of Environment and Natural Resources, Professor
  • Robert Slesak, Minnesota Forest Resources Council, Director of Applied Research and Monitoring
  • Mellissa Youngquist, University of Minnesota
  • Chris Looney, University of Minnesota
  • Jacob Diamond, Virginia Technological University
  • Daniel McLaughlin, Virginia Technological University, Assistant Professor
  • Alan Toczydlowski, University of Minnesota, Researcher
  • Last modified: March 10, 2020