Environmental Commentary by Tim Rowland
Roughly a decade ago, it’s believed that a shipment of young ash trees from a Michigan nursery was used to landscape a rural West Virginia subdivision.
Someone — it’s impossible now to figure out who — ignored a federal quarantine that was in place to halt the advance of a slender, metallic-green beetle native to Asia, which had arrived on our shores in some crating material in the 1990s.
Today, thousands of ash trees in West Virginia’s Eastern Panhandle, and millions nationwide, including many in all of the states in the Chesapeake's watershed, are dying because of innocent-sounding happenstances such as this.
The unfolding story of the Emerald Ash Borer (EAB) is another environmental tragedy compounded by failure to adhere to federal guidelines and a public that can be hard to convince of impending doom.
When the borer was first officially identified in Detroit in 2002, the feds acted quickly to contain the voracious bug — but not everyone took the risk seriously or, for that matter, even knew of its existence. In suburban Prince George’s County, Md., a nursery received ash trees from a Michigan vendor who knowingly violated the quarantine. Other bugs were innocently transported in loads of firewood or brush.
The quarantine breach in Prince George’s County was quickly detected and aggressively treated, but it hardly mattered. Paul Chaloux, EAB national policy manager, said the borer travels fast and has no natural predators here.
In Morgan County, W.Va., the infestation cooked for years before it was detected in 2009, and the pests had thrived in a rich, heavily forested environment.
The EAB was found in southeastern Pennsylvania in 2012 after reaching Pittsburg in 2007, and now all states in the Chesapeake Bay watershed have been infested and quarantined (only Maryland’s Eastern Shore has to date escaped.)
This spring, it’s easy to recognize stands of green, black and white ash that are losing their bark at a stunning rate. It’s a sight that sickens foresters who understand that another great staple of the American forest will soon be gone. Soon ash will join the American chestnut and the American elm, both devastated by disease, as species that were lost to foreign invaders.
Ash is different from chestnut and elm because it’s found in a broad cross-section of the environment. White ash populates ridgelines, while black and green ash are found in riparian areas along streams and in forested swamps.
Their seeds are important forage, and while some species such as sycamore can help fill the void along stream banks, swamps populated by ash will likely be replaced by open marshland, to the detriment of the aquatic habitat.
Disease killed 200 million elms and 3.5 billion chestnuts, but the potential ash losses would nearly double those numbers, combined. In the public conscience, ash built its reputation on baseball bats, but it’s also an important if unnoticed backdrop in urban landscapes, where its toughness allows it to survive exhaust emissions and poor soils.
Baltimore alone has 293,400, ash representing 10.3 percent of the city’s trees, according to Amanda Cunningham, executive director of the Baltimore Tree Trust. Their days are likely to be numbered..
Chaloux said that foresters’ weapons against the infestation are few, but some reasons for faint optimism do exist. One is that every so often a stray ash is not susceptible to the bug, leading to hope that a resistant strain could be propagated. Researchers also went to Asia and Eastern Russia where the EAB is native, to learn of their natural predators. They discovered wasps whose hatchlings feed on ash-borer larvae, and those wasps — they have been deemed safe for American environments — have been introduced into a majority of the 22 states where the EAB has been found.
That won’t help forests that are already infested, but ash resprouts from its roots, and the wasp might be able to protect future generations of trees.
And finally, the U.S. Department of Agriculture is stressing public outreach to keep borer infestations from reaching ash forests that have yet to be affected. At the website hungrypests.com, the department is telling people how to keep from being part of the problem — by taking precautions that include carefully selecting local sources of firewood and buying stock from certified pest-free nurseries, among others.
Most important, of course, is that the public recognizes that predictions of environmental disasters have an inconvenient habit of coming true.
Tim Rowland is a newspaper columnist and author of “Maryland’s Appalachian Highlands: Massacres, Moonshine and Mountaineering.” Distributed by Bay Journal News Service.
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