TROY, Maine — Why were college students pouring gallons of diluted Chinese hot mustard on small squares of Waldo County forest?
It might sound like an unanswerable riddle, but the six Unity College student researchers were busy Monday morning pouring the mustard to draw out earthworms so they can count and measure them.
“We’re looking at the biodiversity and the whole ecosystem,” Taylor Follette, 19, of Talmadge said while waiting for irritated earthworms to emerge from the leaf duff and dirt. The mustard bothers the worms, which come to the surface for relief. The students do douse them with water, but the worms also get counted, measured and added to a growing collection of knowledge about Maine’s threatened hemlock forests.
“This stuff is going to help out landowners that have hemlock stands,” said Jennifer Moran, 21, of Clarksville, Tenn.
Many of those stands are in danger, according to Allison Kanoti, forest entomologist with the Maine Forest Service. The hemlock wooly adelgid invasive pest has been creeping up the coast of Maine and first was spotted in 2003. It has now been found on hemlock trees from Kittery all the way to Bristol, and Kanoti said the wooly adelgids likely are in other locations as well — including Mount Desert Island, where they were found last fall on ornamental hemlock trees. Adelgids kill by eating the sap, starving the trees of food.
In other states, the tiny insects have ravaged hemlock forests, killing trees in a handful of years. Because they are slowed by cold temperatures, tree mortality in Maine has not happened so quickly, the entomologist said.
Although forest service scientists have put plots in place to monitor for post-arrival effect of the wooly adelgids, they would like to identify stands of hemlock along the coast north of Bristol. They also could use help getting more detailed information on what the forests are like before the insects get there, and that’s where the students’ summer research project comes into play.
“Hemlock is a native species, and an important part of Maine,” Unity College ecology professor Amy Arnett said Monday of the tree she calls foundational to the state’s forests. “Hemlock is really dominant. Its needles change the soil and it’s really shady. What’s going to regenerate? What will forests in Maine look like without hemlock?”
For six weeks, her student researchers have been getting to the woods in the early morning to collect data about 58 small plots of land around western Waldo County that will help answer that question.
It’s the third year that Unity College has been part of a major grant from the National Science Foundation’s Experimental Program to Stimulate Competitive Research. The $20 million grant created the Sustainability Solution Initiative, bringing together researchers from the University of Maine, the University of Southern Maine and other Maine higher education institutions. The project is aimed at helping Maine communities learn how to sustain their resources in the face of a variety of threats that include the tiny but terrible hemlock wooly adelgid.
Courtney Tway, 22, of Chillicothe, Ohio, is the student supervisor on the project. She said that the group has been busy measuring soil moisture, counting invertebrate species, analyzing how much light comes through the tall hemlock canopy and hits the forest floor and more. Next week, some of the hemlock trees will be girdled — a technique which will have the same deadly effect as the adelgids — and next summer the students will be collecting data about how that will affect the forest plots.
“It’s been a blast,” student John Crowe, 21, of Stoneham, Mass., said of his summer job. “We’re getting exposed to a lot of different collection methods.”
Arnett said the student researchers have been a very important part of the project.
“They’re doing great,” she said of the group.
But as she walked through a part of the forest that was logged three years ago, she gestured to the hemlock trees that stood tall in the dim, filtered sunlight.
“Mainers basically have to get ready for the forests to look very different in the next couple of decades,” she said.