Biological invasion threatens keystone species indelibly entwined with Indigenous cultures

Black ash (Fraxinus nigra), the most highly preferred and vulnerable host of the invasive emerald ash borer (EAB; Agrilus planipennis) in North America, is of cultural and spiritual importance to many Tribal Nations in the US and First Nations in Canada. To date, EAB has invaded nearly 60% of the native range of black ash, with annual spread averaging approximately 50 km per year. On the basis of the predicted expansion of EAB distribution, we estimate that more than 75% of black ash basal area will be lost across 87% of the species' North American range by 2035. Census data indicate that 98% of Indigenous people currently residing within the geographic range of black ash in the US will be within the area experiencing more than 75% basal area loss by 2035, suggesting broad and multidimensional impacts of EAB invasion for those who value black ash as a cultural keystone species. Collaborative efforts among scientists, resource managers, and Indigenous experts are needed to mitigate EAB impacts and preserve or protect black ash resources, given the species' vulnerability to EAB and its associated cultural and ecological value.