Emerald ash borer beetle. Photo: David Cappeart, Michigan State University, via bugwood.org
On Maryland’s Eastern Shore, the emerald ash borer (known in forestry circles as EAB) may destroy most or all of an unusual but characteristic local environment. Some largely undisturbed but ecologically crucial tidal wetlands forest will likely be eliminated by this invasive insect. The prospects are dim.
In wet tidal forests, particularly in the south of the Delmarva peninsula, the emerald ash borer destroys ash trees by eating their soft underbark and preventing nutrient flow. Once infested, these important trees die in two or three years. Ash trees live where other trees cannot, in freshwater wetlands where the changing daily tidal levels kills the other trees. When allowed to grow in their native habitat, ash trees act as ecosystem engineers that create soil and mounds. This soil and mound environment combined with tidal water-level changes cleans and filters the water that flows in from, and then out to, rivers. Clean rivers mean a clean Chesapeake Bay.
The tidal wetlands constitute about 10% of lower Eastern Shore land. The wetland forests not only benefit local waters, but also protect themselves. If nothing else, humans need boardwalks to traverse the wetlands. Because two-legged humans and their heavy construction equipment used for real estate development do not easily travel in swamp county, the wetlands are preserved. As well, riverbank and wetland forests offer farmland protection from storm-caused river flooding.
The ash borer likely arrived in the U.S. in the 1990s, carried by wooden packing material from China. The invading bug was first identified in Michigan in 2002 and in Maryland’s Prince George’s County in 2003. It was found to infest Eastern Shore ash trees in 2015. Former Gov. Martin O’Malley declared an Emerald Ash Borer Awareness Week in 2012.
Controlling the ash borer requires effort and money. Citizen action includes keeping and burning firewood only in local areas. Firewood transported likely means emerald ash borers are transported. Landowners should at least contact the local Agricultural Extension, and have trained foresters remove infected trees, including the fallen ones.
In the long run, eliminating the ash borer may be impossible. An ash tree species genetically engineered to resist the borer is possible, but not likely to appear soon. Failing that, the only (partial) remedy may be to replace lost ash trees with another species.
Information about citizen action is at these links:
Homeowner’s Guide to Saving Ash Trees from the Emerald Ash Borer Beetle, University of Maryland Extension.
https://mda.maryland.gov/plants-pests/Documents/EAB%20Homeowners%20Guide_July%202016.pdf
Maryland Department of Natural Resources Firewood Policy.
https://dnr.maryland.gov/publiclands/pages/firewood.aspx
Emerald Ash Borer, University of Maryland Extension Service https://extension.umd.edu/resource/emerald-ash-borer-eab
State governments can make some large-scale efforts to reduce the EAB’s harm. These operations include:
This New York Times story is a must-read if only for its gorgeous photography:
"Can a Hidden World be Saved from an Invasive Scourge?" Gabriel Popkin and Leslie Brice, New York Times, Feb. 21, 2022.
https://www.nytimes.com/2022/02/21/opinion/invasive-pest-forest.html
The U.S. Forest Service has EAB control and management information: https://www.nrs.fs.fed.us/disturbance/invasive_species/eab/control_management/
The Nature Conservancy has a terrific website about the Nanticoke River Watershed: https://www.nature.org/en-us/about-us/where-we-work/united-states/maryland-dc/stories-in-maryland-dc/nanticoke-river-watershed/
Wicomico County Climate Change has a website not-to-be-missed (especially the “Tidal Wetlands” page): https://wicoclimate.weebly.com/
Jim Block taught English at Northfield Mount Hermon, a boarding school in Western Mass. He coached cross-country, and advised the newspaper and the debate society there. He taught at Marlborough College in England and Robert College in Istanbul. He and his wife retired to Chestertown, Md. in 2014.
Title image: Pond at Pickering Creek Audubon Center, Talbot Co. Photo: Jan Plotczyk