Dutch elm disease (DED) is a deadly disease that over the decades has slowly killed most healthy American elm trees in New England, and it is spreading across the country. The 80-foot tree on my mother’s property on Dorset Street is unusual for several reasons, the least of which is its size; most elm trees don’t get the opportunity to grow this big because they’re killed by DED before they can get that tall. My mom’s tree is probably over a hundred years old.
Ecologist Gus Goodwin and researcher Christian Marks from The Nature Conservancy (TNC), and arborist Mac Swan from Limbwalker Tree Service, came over to check out my mom’s tree last Wednesday because it shows signs of being resistant to DED, and trees that show this resistance are critical for restoring the elm tree population to its prior health and majesty. In scientific terms that I can understand, Goodwin described the tree as being “pretty damn resistant.”
Two branches on the left of the elm show signs of having had DED at one point; Marks explained that trees infected the disease usually die within a year, but this one is still alive and even growing buds. This means that the tree is not only not dying, it’s continuing to flourish; adding to its importance for scientists is the fact that the elm is located in close proximity to other elms that have succumbed to DED.
Swan hauled himself up into the canopy of the tree—wearing a bunch of gear that looked like he was about to go rock climbing—and sawed some budding branches off the top, while my mom, who hates danger, heights, and tree climbing, warned him 300 times to be careful. As he cut the branches and threw them to the ground, Marks collected them and quickly wrapped the stems in wet towels and packed them up into a big cardboard box marked “fragile.” He was later going to Fed Ex them overnight to a lab in Ohio.
Once it arrives, my mom’s elm tree will be cross-pollinated with seven other elm trees that have proven to be DED resistant, and once they are large enough, the elms will be plated on a floodplain forest restoration site. In three to five years, these young trees will be injected with DED, and whichever ones survive and hopefully prove to be hearty enough to resist the disease will be made available to the public and planted in other floodplain restoration areas.
Elm trees once lined many suburban streets and shaded parks and forests with their vast canopies, but that is no longer the case. Aesthetics are only a small part of why Marks said he is working so hard so that “elms can be big trees again and dominate the canopy of their natural habitats.” The trees are also important ecologically because they grow to fill canopy gaps after floodplain pioneer trees die, and have a unique combination of flood tolerance and shade tolerance that enables them to thrive in these environments. The elm’s inability to fill this need changes the ecological structure of the floodplain forests.
The story reminded me of the book The Immortal Life of Henrietta Lacks, which detailed the way in which one woman’s DNA went on to be used in countless scientific experiments and was useful in research for, among other things, developing the polio vaccine. We joked that we should name the elm Henrietta; minutes later, in a psychic moment, my sister texted me that exact thing, so the tree’s name is sealed.
We won’t know what happens with these buds for many years, but it’s nice to think that Henrietta, our tree on Dorset Street here in little old Charlotte, could one day be a little part of a large canopy of thriving, lush American elms across the country.