Black Ash, the Corky Barked Wonder Tree

Charlotte Cadow walks through a forest with black ash trees and sphagnum moss covering the forest floor.
Charlotte Cadow

On a quest to monitor and inventory Vermont’s corky-barked wonder, the black ash tree (Fraxinus nigra), UVM Field Naturalist Program graduate student Charlotte Cadow has spent the summer hopping, plunging, and tromping through seeps, swamps, and floodplain forests.

Black ash trees are a cultural centerpiece for many Indigenous peoples in northeastern North America, including members of the four state-recognized tribes and the many other Abenaki and Indigenous peoples both from, and settled in Vermont. Black ash is most commonly used by these and other tribes for making baskets, but is also used for a variety of other purposes, including fish weirs, woven furniture, barrel hoops, and canoe thwarts. Basket-tree harvesters identify and fell the trees, having been trained to identify the specific tree attributes that indicate basket quality black ash. The trees are then processed into splints for basketry. Ecologically, black ash trees play many vital roles including moderating hydrologic regimes, providing wildlife habitat, and contributing to nutrient cycling.

A black ash tree with the bark taken off to show the tunneling caused by emerald ash borer.
Tunneling in an ash tree caused by emerald ash borer.

Juxtaposed with this cultural and ecological significance is the imminent disappearance of black ash trees from the landscape. Emerald ash borer (EAB) larvae are infesting and killing ash trees across North America. In 2018, foresters confirmed the first signs and symptoms of EAB in Vermont. Today, EAB is documented in nine of the 11 counties in the state in both urban and forested settings. Black ash trees haven’t shown any resistance to these infestations, and are critically endangered.

In conjunction with the Vermont Urban and Community Forestry Program, a partnership between UVM Extension and the Department of Forests, Parks and Recreation, Cadow has spent much of the summer field season establishing long term monitoring plots, collecting information about black ash stand dynamics and the attributes of individual trees. As EAB continues to infest, girdle, and kill Vermont’s ash trees, and black ash trees disappear from the landscape, UVM Professor Tony D’Amato, director of the Rubenstein School’s Forestry Program, will be using these plots to observe shifts in tree species composition and, in some cases, evaluate the efficacy of insecticide injections to preserve black ash in these forests for long-term cultural and ecological values.

To inventory Vermont’s black ash trees, Cadow has established an iNaturalist project to collect data about the distribution and health of black ash trees in Vermont. Qualifying observations start with basic geolocated photos, but include options to describe the canopy, presence of EAB sign, site hydrology, and diameter at breast height (DBH). There’s also a field for observations from private land that queries about the landowner’s willingness to invite basket tree harvesters to access those trees, and asks for contact information. At present, there are 285 black ash observations in the project.

A person is using a special measuring tape to find the diameter at breast height of a black ash tree.


To view or add observations to the iNaturalist project –

To learn more about the ecological and cultural significance of black ash in Vermont, listen to episode six of the Heartwood podcast, a collaborative effort between UVM Extensions Kate Forrer and Ginger Nickerson and Lisa Sausville of Vermont Coverts –

Follow this link to read more about Charlotte Cadow’s black ash adventures –

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