Harvard Undergraduate Thesis on Garlic Mustard, an Invasive Plant

Dunbar Nathan Carpenter (Harvard '08) has completed his Senior Thesis in Biology, "Regional and Historical Influences on Exotic Plant Invasions - The Ecological Drivers of Garlic Mustard (Alliaria petiolata) Invasion in Western Massachusetts". This work draws upon research initiated in the Harvard Forest Summer Program investigating the ecological and historical factors driving the distribution of garlic mustard, a highly invasive plant. Dunbar completed his analyses and writing with oversight from Kathleen Donohue, Kristina Stinson, Missy Holbrook and David Foster while enrolled in the ecology research seminar OEB 198. The data show a higher occurrence of garlic mustard in the Berkshire Valley than in the Connecticut River Valley that is most likely related to the history of invasion rather than climate or environmental differences between the regions. Different factors appeared to influence the plant's establishment at open sites, its invasion into adjacent forests, and its abundance in the understory. These findings broadly suggest that history and geography, in addition to environment, are important to consider in interpreting or anticipating plant invasions at the regional scale. Dunbar has also contributed to recommendations for invasive species control at the Harvard Forest.