Claudia Villar-Leeman ’15 Studies the Future of Forests

Claudia Villar-Leeman with her mentor, Ahmed A.H.Siddig, a PhD candidate at UMass.

In the Harvard Forest: Claudia Villar-Leeman ’15 with her mentor, Ahmed A.H.Siddig, a PhD candidate at University of Massachusetts.

Claudia Villar-Leeman lived in the woods for 11 weeks this summer to investigate the “chaotic” changes that a bug the size of a dot is wreaking on East Coast forests.

The biology major won a National Science Foundation fellowship to work with scientists who are looking into the decline of eastern hemlock trees. In 18 states, the conifers are being wiped out by the hemlock woolly adelgid, an invasive insect from Asia.

First accidentally introduced to the United States in the 1950s — possibly by someone importing an ornamental hemlock from Japan — the pest is at this point unstoppable. “Hemlocks are doomed,” Villar-Leeman said. “I am not sure if they will go extinct, but the bug is uncontrollable and scientists are studying how the forests will change after the die-off.”

With 22 undergraduates (selected from an applicant pool of over 700), as well as graduate students and seasoned scientists, Villar-Leeman worked in the Harvard Forest, the university’s 107-year-old, 3,750-acre ecological research area in Western Massachusetts. She both contributed to a long-term hemlock study and conducted her own research into how salamanders are being affected by the disappearing conifers.

claudiaHemlock forests are heavily shaded, offering cool and stable environments for certain species, including eastern red-backed salamanders, native brook trout, and birds such as wood warblers and vireo. Hemlock woods are also important for moose, which seek out the forests in the winter as the thick tree cover prevents much snow from accumulating on the ground.

To study long-term effects of the hemlock decline, scientists at Harvard Forest are simulating real life. For instance, when landowners see their hemlock trees dying off, they tend to chop down the trees to salvage the wood. Researchers are mimicking this behavior in sectioned plots of the forest to see how removing logged timber affects the surrounding forest. They can compare these logged areas to plots where dying hemlock are left to naturally fall to the ground and decay. “Creating a swathe of land without hemlocks might make it harder for the adelgid to spread, but may have other unintended ecological consequences,” Villar-Leeman said. “It is important to know whether we should be advising landowners to cut down hemlocks or to allow them to be colonized and killed by the adelgid.”

Villar-Leeman’s job for the long-term study was to measure every tagged tree present in the experimental plots (of which there are over 6,000) and report on their status, a “pretty tedious” task, she admitted. On the side, she investigated whether the removal of logged hemlock trees affected salamander abundance, as salamanders may prefer habitats with an abundance of downed woody debris.

In the future, as eastern hemlock forests become scarcer, red-backed salamanders will decline, Villar-Leeman predicts. When hemlock trees die, light floods into formerly dim forests, drying them out and creating “all types of chaos,” she said. But as other hardwood saplings grow into leafy trees, replacing the hemlock stands with a new type of forest, the salamanders might return, though probably not to the same abundance.

The summer of research also led to a scientific collaboration for Villar-Leeman. She is co-authoring a paper with her summer mentor, University of Massachusetts Ph.D candidate Ahmed A.H. Siddig. In their paper, they question the value of the ecological indicator species for predicting environmental conditions. Siddig, in an email, praised Villar-Leeman’s scientific motivation and hard work, as well as her interest in linking her science background to community service.

After she graduates next May, Villar-Leeman plans to take a year to travel and volunteer with environmental nonprofits around the world. “I want to better understand how we can bring scientific understanding into the lives of people living in environmental degradation or in poverty, which is often linked to environmental degradation,” she said. “I want to do something connected to human communities and social justice.”