by Kristen Munson, University of Vermont
Near the bottom of a shady hillside in Jericho, a lone beech tree stretches high into the canopy, a relic of a bygone forest. Through luck or (hopefully) genetics, this mighty tree has avoided contracting beech bark disease—a fatal fungal pathogen that has proven deadly to mature beech trees. And it stands just outside a hotspot where a new pathogen called beech leaf disease (BLD) is spreading across Vermont forests.
"Beech is here a lot as a sapling … but if you look out into the forest it's not really common in the overstory," said Jess Wikle Ph.D. '24, lecturer in forestry and manager of the University of Vermont's Research Forests. "There is a reason for that."
In the late 1800s, beech bark disease arrived in Nova Scotia and slowly expanded throughout Northeast forests. By the 1960s it was prevalent in Vermont. The disease is caused by infestations of a tiny scale insect that introduces a fungal infection to the vascular tissue of the tree. The once smooth beech bark gains a pock-marked appearance. While the disease progresses slowly, estimates suggest between 50 and 90% of mature beech eventually die from it.
"There are definitely way fewer big trees than there used to be," said Wikle, "but there are still trees that have resisted the beech bark disease for a long time."
