Date of Award

Spring 2013

Document Type

Thesis

Degree Name

Master of Science in Biology - (M.S.)

Department

Federated Department of Biological Sciences

First Advisor

Daniel E. Bunker

Second Advisor

Jessica Lee Ware

Third Advisor

Simon J. Garnier

Abstract

White-tail deer (Odocoileus virginianus), a generalist herbivore, are widely considered to influence ecological communities, ecosystems and human wellbeing by foraging preferentially on certain plant species. Previous research has shown that high deer density can change the relative abundance of tree species in forest communities. Furthermore, some evidence shows that resistance traits of plants can influence plant photosynthetic ability which is an important factor in an ecosystem. The purpose of this experiment is to test whether plant resistance traits can change within species when they are exposed to high levels of deer herbivores. The experiment, established in 1979, enclosed deer within forest stands at high and low densities. Resistance traits of five dominant woody plant species were sampled from individuals that established during the deer density treatments and are now adults. Plant resistance traits (Leaf mass per area, Leaf dry matter content, C:N ratio, and Wood density) were tested and compared between low and high deer density area by using mixed effect statistical models. Leaf mass per area (LMA), leaf carbon—nitrogen ratio (C:N), and wood density did not respond significantly to increasing deer density. However, leaf dry matter content (L D MC) showed a slight but significant increase in response to high deer density. These results indicate that this plant trait may respond to increasing deer density, resulting in potential impacts on ecosystem functioning.

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Biology Commons

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