The density of white-tailed deer, Odocoilus virginianus, has been increasing throughout the Hudson Valley due to changes in habitat, a reduction in predation, and even climate change. High densities of deer have been observed at the Vassar Farm and Ecological Preserve since the early 1990s. Overabundant deer have been shown to negatively impact biodiversity, cause changes in species composition, and alter the structure of the forest. Deer exclosures are a commonly used to isolate the effect that deer are having on a forest. In 2008, we erected deer exclosures at three forested locations on the Vassar Ecological Preserve. Each fenced area was paired with an adjacent unfenced area of equal size. To better understand the impact that the deer are having on the forests, we are comparing the vegetation and soil from the paired plots. Students in the Introductory Biology and Ecology classes collect and analyze datum for this projects. It is also studied by students for independent research projects.
This summer, we will sample the vegetation at two nearby sites that have had deer exclosures in place for 20 years. We will also sample the vegetation at the exclosures on the Vassar Ecological Preserve. Each of these sites has a different deer management strategy and therefore deer densities are likely different. By examining the differences between the sites we will make predictions about the possible trajectories of the forested system on the Vassar Ecological Preserve and make recommendations about how deer should be managed to support biodiversity.