When large mammalian predators are extirpated or hunting pressure from humans is insufficient, mammalian herbivores like white-tailed deer increase in density, exerting increased pressure on plant communities. Though such effects are well-documented, it remains untested how herbivore-induced changes in vegetation ricochet back up the new food chain in these altered plant communities. Making use of a unique long-term experiment where deer density was manipulated in large enclosures, preliminary data demonstrate that deer density during stand initiation (the first 10 yr following clear cut) causes significant legacy effects in forest canopies, including trees, insects, and birds, lasting at least 30 years. The current project investigates mechanisms by which this legacy operates from scales ranging from stand to individual tree to individual prey item. Preliminary data provide support for mechanisms such as reduced foliage density, reduced prey base per unit foliage, and reduced prey quality at high deer density, all due to stand-scale changes in tree species dominance caused by deer. New investigations in these stands include bird foraging observations and bird exclusion experiments to examine at what scale and by what mechanisms birds respond to changes in forest vegetation caused by historic deer browsing.
Results from this study are relevant to the ca. 30% or more of eastern US counties where deer are over-abundant. Findings will be disseminated directly to state, federal, and tribal land managers via training programs coordinated by the USDA Forest Service Northern Research Station. The project will broaden participation by under-represented minorities in three ways. First, the PI is Native American, a group that is under-represented in STEM disciplines, particularly so in ecology. Second, the PI will provide mentorship via Indiana University of Pennsylvania's McNair program, a research mentorship program for undergraduates from under-represented groups interested in pursuing a PhD. Third, the PI will work with IUP students to establish a SEEDS chapter, a program of the Ecological Society of America that seeks to enhance opportunities for students from under-represented group to pursue careers in ecology.
