“This is what I consider my dating service,” says Marks.“We have resistant trees from Ohio, from Pennsylvania, from the Midwest. We’re putting them together and breeding them with each other. The trees are planted in different environments and carefully monitored.He has to be concerned about little things—whether rodents will gnaw through the bark, if the trees are spaced far enough apart. “They once would have formed magnificent stands in floodplains like this.They’re so ecologically important, and it’s hard to overstate their beauty. But’s it going to take a lot experimentation.” As canopy trees, American elms once affected the ecology of the entire floodplain forest, the rich, fertile habitat that periodically floods along rivers (and also provides flood control and cleaner water for people).But most people knew them as trees of town and farm.They were the perfect tree for shade, to line city streets, to provide stately paths through college campuses. “American elms could take a lot of abuse, from roads, from salt, from pollution,” says Marks.
As such, there are still small spindly elms in the forest. Marks follows any lead, although many turn out to be backyard and farmland trees that are not actually resistant, just isolated. In fact, during our planting trip, Bartholomew’s Cobble steward Rene Wendell directed Marks to an old surviving elm, a tree that Marks noted for future investigation. Forest Service’s web site) Once a tree is determined to be resistant, Marks and partners collect clippings for restocking. “There isn’t a single genetic trait that provides resistance,” says Marks.The Conservancy’s Angela Sirois-Piteo helps plant elm cuttings which may one day return this iconic tree to its rightful place in eastern ecosystems.