Is One Tree As Good As Another? The Incipient Extirpation of Ash Trees From New England Forests

Join Matthew Ayres, Professor of Biological Sciences at Dartmouth, at the Dartmouth Organic Farm for a discussion of the extirpation of ash trees in New England. This talk is co-sponsored by the Howe Library and the Hanover Conservancy. It will be held under cover, but outdoors, at the Dartmouth Organic Farm, located at 104 Lyme Rd in Hanover. Please dress accordingly! The emerald ash borer (EAB) was accidentally introduced to the Port of Detroit from northeastern Asia sometime before 2002. In Asia, EAB feeds chiefly upon weakened ash trees (Fraxinus) that lack the strong chemical defenses of healthy trees. However, all North American ash (about 16 species) lack competent defenses against EAB and inevitably die within a few years of attack by EAB. Millions of ash trees in North America have been killed so far by EAB. EAB has reached New Hampshire and is in the process of extirpating ash from forests, parks, and yards. What will be the consequences? In 2022, the ash protection experiment was implemented in the Hubbard Brook Experimental Forest, within the Whire Mountain National Forest, to compare forest stands where ash trees remain with stands where the ash are being killed by EAB. Effects might be minimal if ash are functionally redundant with the other tree species that will survive or ash may have unique characters such that the aftermath forests will be forever different. This presentation will describe what we have learned so far about whether one tree is as good as another. We will invite your ideas for what we most need to know. Matthew Ayres is Professor of Biological Sciences, the graduate program in Ecology, Evolution, Environment and Society, Dartmouth College. Ayres studies the ecology of forest insects.