Scanning the Schoolyard for Hemlock Health

SciStarter has a whole round-up of tree-related projects for you this season. Branch out into citizen science! Screen shot 2013-09-21 at 10.09.02 PM

Massachusetts is on guard. Only the watchers are not local police or state troopers; they are the students of John R. Briggs Elementary School in Ashburnham, Massachusetts. Led by their teacher, Ms. Katherine Bennett, these young scientists scurry through the low-lying boughs of eastern hemlock (Tsuga canadensis), stopping at each tree to peer underneath the leaves, particularly trees that have been flagged with orange tape bearing an identification code. They’re looking for small white blisters clustering along the pale underside of the hemlock needles, a sure sign of the hemlock woolly adelgid. Turning over the branches, students record findings and observations in data columns and scribble doodles in the margins.

The activity is part of an ongoing partnership between schools in New England and the Harvard Forest to provide an outdoor classroom for young students and extra eyes on the ecology of the region. This project, one of three ongoing projects in Harvard’s Schoolyard Long Term Ecological Research program, focuses on monitoring this invasive arthropod. The hemlock woolly adelgid (Adelges tsugae) is native to East Asia where it feeds, relatively harmlessly, on hemlock trees.

In the United States, free from the natural constrains of predators, Adelges tsugae can infest an entire tree and drain it of life by sapping away vital nutrients and sugars from the hemlock leaves. The branches cease to grow as vigorously once infested and eventually shrivel and die, killing the tree after five to ten years, depending on conditions. The adelgid was first reported in the United States in 1951. Since then, the little arthropod has crawled, hitch-hiked, blown, and tossed its way over 18 states across the East Coast, ranging as far south and west as Tennessee and northern Alabama to the southern tip of Maine.

It’s now in every county of Massachusetts, where kids in participating schools like John R. Briggs are able to study it and other invasive plants and animals. Bennett teaches it as a culmination of a forest ecology unit covering the basic biological topics like plant anatomy and physiology, and photosynthesis. Ms. Bennett says it integrates very well with “next gen science standards including learning about what scientists do…and taking data, like real scientists, doing the same kinds of studies and experiments that real scientists do.” And engaging in the motions of “real scientists” is exciting for students and stimulates learning and imaginative discussions, where they’re able to talk about pressing issues such as climate change or invasive species.

Besides training a new generation of scientists, the citizen science influence ripples away from the schoolyard. Parents report being pressed into ecological service by their children and carried into their backyards or forests to tear up garlic mustard or Japanese knotweed or look for signs of the hemlock adelgid. For the project, the students may be looking at ten branches on ten hemlock trees, and they detail new branch growth, egg sac density, and presence/absence of the hemlock woolly adelgid.

The data the children collect are sent to Harvard Forest to be analyzed and archived by Dr. David Orwig, an ecologist at Harvard. “[These data] are valuable,” Dr. Orwig says. “As there are still not good data at the branch level from year to year.” If the participating schools stick with the project for many years, the data can be used to investigate how the adelgid has impacted hemlocks in different regions and why. These are questions that are still unanswered and may provide some of the keys to damming the flood of invasion.


Many schools still don’t have the adelgid in their areas, so the children can be the first to discover it. In fact, last year in Ashburnham, Bennett’s class of fifth graders discovered the adelgid in the area. They and Dr. Orwig were able to file a report with the state Department of Conservation and Recreation with their findings. If the students find hemlock woolly adelgid in new areas, like Bennett’s class, then scientists such as Dr. Orwig can use these data as a record of how long trees last.

While these data are useful, perhaps the most rewarding part of the project for scientists such as Orwig and teachers like Bennett is watching the students become more responsible and ecologically literate citizens. “The best,” Dr. Orwig says, “is when you can interact with students in nature to share knowledge with them in a natural setting.” Orwig always visits participating schools each year just for that moment. The students develop a deep and tangible relationship with the natural world around them, which both Orwig and Bennett agree is apparent.

“I’ll never forget this,” Bennett says. “There was one kid that was just a video gamer, and that was it. He said, ‘I never spend any time outside; I always play video games.’ Then he came in in the spring with two little acorns that were sprouting. He was so excited, and he said he wanted to grow them into oak trees.”

If you are a K-12 educator in New England or in an area affected by Hemlock Woolly Adegid, get involved with this project. And you can contact Dr. Orwig or Pamela Snow, the Schoolyard LTER coordinator at Harvard Forest. You can find their contact information below.

Official Harvard Forest website

Pamela Snow:
David Orwig

Images: Harvard Forest, Katherine Bennett

Angus Chen is the managing editor for the SciStarter Blog network which includes the Discover magazineCitizen Science Salon” blog and the Public Library of Science’s Cit Sci blog. He’s also a freelance reporter and producer at WNYC Public Radio on “The Takeaway” with Public Radio International and the NY Times. You can also read his work with Science magazine. He was once a scientist studying geology and ecology, but now spends his days typing and scribbling and sketching furiously. When he gets the time, he makes cool videos.


Categories: Citizen Science, Ecology & Environment, Nature & Outdoors, Science Education Standards