A non-native, hemlock-loving invasive species known as the hemlock woolly adelgid is wiping out stands of Eastern hemlock throughout the East Coast of the U.S.
A non-native, hemlock-loving invasive species known as the hemlock woolly adelgid is wiping out stands of Eastern hemlock throughout the East Coast of the U.S. Though no trees survive completely, some stands are able to resist the invasion for longer than others, and the Department of Energy recently awarded $999,990 to a team of scientists, led by Ashley Keiser, assistant professor in the Stockbridge School of Agriculture at the University of Massachusetts Amherst, to find out why.
The hemlock woolly adelgid first arrived in the U.S. in the early 1950s, and, as the climate has warmed, it has spread from its initial berth in Virginia to 19 different states, from Georgia to Maine and west to Michigan. The insect feasts on the sap of Eastern hemlock, slowly starving the tree. Many of the infected hemlocks will die slowly over the course of a decade — but not all of them.
“There’s been an unequal decline,” says Keiser. “In fact, at the Harvard Forest in central Massachusetts, there are two different, non-contiguous stands of hemlock, each infected with hemlock woolly adelgid at the same time. One stand is suffering badly, but the other seems to be managing the infection.”
Read more at: University of Massachusetts - Amherst
An unhealthy stand of Eastern hemlock (L) versus a stand on the right that is better coping with the wooly adelgid. Both stands are in the Harvard Forest. (Photo Credit: Corey Palmer)
