The planting will help diversify the forest canopy and build resilience ahead of EAB impacts
The Minnesota Department of Natural Resources recently completed a project to plant 58,800 tree seedlings in the understory of ash-dominated state forest land in north-central Minnesota. This planting seeks to establish a more diverse mix of tree species ahead of the anticipated loss of ash trees to emerald ash borer, which threatens the ecological function of forests where ash are currently the primary species.
Crews hand-planted white cedar, hackberry, silver maple and swamp white oak seedlings grown at the State Forest Nursery on three sites near the edge of known EAB advancement. Research shows that the chosen species can tolerate the tough growing conditions often found in ash-dominated wet forests or swamps. Seedling planting often happens in spring, but fall is preferred on these swamp sites because it’s drier and easier for crews to work.
“Our hope is that this project will give us one more tool to keep these ash swamps forested into the future,” said Chris Gronewold, DNR Silviculture Program coordinator.
EAB is an invasive insect fatal to all three of Minnesota’s ash species. With an estimated 1 billion ash trees in the state, EAB is a threat to tree canopies in forests and urban communities. In northern woodlands, ash often dominate an ecosystem type known as wet forests, which have important ecological functions like water filtration, flood mitigation and providing habitat for uniquely adapted plant and animal species.
With greater diversity of established tree species, wet forests have a better chance of maintaining these functions rather than transitioning away from forest cover after ash trees die. DNR foresters will monitor the sites after planting to track the seedlings’ health and growth.
These plantings are among many efforts the DNR and other agencies are undertaking to prepare for, adapt to, and mitigate the damage from EAB. The public can help slow the spread of EAB by not moving firewood outside quarantine zones. EAB is regulated by the Minnesota Department of Agriculture. For information on quarantined counties and more, please refer to MDA’s Emerald Ash Borer Program webpage.