Date of Award


Document Type



College of Arts and Sciences

Degree Program


Degree Name

Master of Science

Thesis Advisor

Dr. William Rogers

Committee Member

Dr. Janice Chism

Committee Member

Dr. Paula Mitchell


Herbivory, Browse damage, White-tailed deer, Hispid cotton rat, York County, Mecklenburg County


Herbivory is a ubiquitous ecological process, yet its importance to plant community ecology and conservation biology is controversial. When Schweinitz's sunflower (Helianthus schweinitzii T&G) was listed as a federally endangered species in 1991, "Predation and Parasitism" were considered "not applicable" as threats, and it was the lack of large herbivores that was repeatedly identified as a threat to this species' survival. Two decades later, persistent negative population trends in many protected populations and anecdotal reports of "heavy browse pressure from white-tailed deer" led to suggestions that herbivory by deer could be impeding the recovery of this species. To test for the existence of heavy deer browsing and the hypothesized relationship between high levels of browsing and sunflower population declines, this study tracked over 1,000 individual Schweinitz's sunflower stems from seven populations in York (SC) and Mecklenburg (NC) counties during the growing season of 2013 to assess browsing herbivore impacts across a range of populations with previously reported declining and non-declining population trends.

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Biology Commons