Identifier

etd-10212005-130147

Degree

Master of Science (MS)

Department

Renewable Natural Resources

Document Type

Thesis

Abstract

Studies in upland forests of the northeastern and upper mid-western U.S. indicate that high densities of white-tailed deer can reduce vegetation abundance, survival, and richness through over-browsing. In the southern U.S., few studies have examined the effects of deer herbivory on vegetation, and even fewer have done so in forested wetlands. At Jean Lafitte National Park's Barataria Preserve in south Louisiana, managers were concerned that white-tailed deer were concentrating and limiting forest regeneration near a walking trail, where hunting is not allowed. An exclosure study was started there in December 2002 and was conducted through July 2004 to quantify the effects of white-tailed deer on forest regeneration. Differences in densities and heights of naturally occurring tree and woody shrub species > 15 cm but < 200 cm in height were compared between six pairs of fenced and unfenced plots under the forest canopy. Fraxinus pennsylvanica and Quercus nigra juveniles also were planted in these plots, and survival and growth were compared between treatments. Naturally occurring shrub and juvenile tree abundance was compared among plots in treefall gaps and the paired plots under the forest canopy. White-tailed deer decreased the survival of planted Fraxinus pennsylvanica juveniles, but did not affect planted Quercus nigra juveniles or naturally occurring shrubs and juvenile trees. Juvenile trees were ten times more dense in treefall gaps than under the canopy because of the dominance of the exotic Triadica sebifera in gaps. Gap disturbances may be reducing diversity in these coastal wetland forests, rather than promoting diversity as they do in other forests. A more complete understanding of how deer modify the landscape may require future exclosure studies in treefall gaps.

Date

2005

Document Availability at the Time of Submission

Release the entire work immediately for access worldwide.

Committee Chair

Andrew Nyman

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