Between a Rock and a Hard Place: Effects of Co-occurring High Deer and Exotic Plant Densities on Deciduous Forests
Bourg NA, McShea WJ, Steward CM. 2012. Between a Rock and a Hard Place: Effects of Co-occurring High Deer and Exotic Plant Densities on Deciduous Forests
The relationship between white-tailed deer (Odocoileus virginianus) populations, herbivory and exotic invasive plant species proliferation has received little study, despite its potential impacts on native biodiversity and natural areas management in eastern North America. To address this important ecological issue, we conducted a multi-year, controlled field experiment using a 2x2 factorial design at three mid-Atlantic upland deciduous forests. Treatments plots where exotic invasive plant species were removed that had high initial invasive cover, singly or in combination with deer exclusion, exhibited the most beneficial response for species richness, abundance and diversity of native herbaceous plants and woody seedlings, while deer exclusion alone was the primary factor causing significant increases in the number and species richness of native woody saplings, large shrubs, and vines > 30cm in height. Shifts in the composition of the native sapling community associated with deer exclusion were also evident through effects on rates of abundance change. Oaks (Quercus spp.) benefitted only when both invasive removal and deer exclusion occurred, whereas shade-tolerant maples (Acer spp.) showed no clear abundance changes across treatments. We also found evidence of declines in invasive species abundance over time in deer-excluded plots, particularly for Japanese stiltgrass (Microstegium vimineum). Our study demonstrates that both invasive plant and deer control are needed for native forest community restoration, and that resource managers must plan for resolution of both issues to achieve forest conservation on their lands.
- Type
- Unpublished Report
- Authors
- Bourg, Norman; McShea, William; Steward, Chad
- Date of Issue
- 2012
- Units
- CHOH , GRFA , GWMP
- Keywords
- Deciduous forest, Diversity, Exotic Plants, Forest Management, Herbivory, Invasive Species, Richness, White-Tailed Deer
- Subjects
- Ecological Framework: Biological Integrity | Invasive Species | Invasive/Exotic plants , Ecological Framework: Biological Integrity | Focal Species or Communities | Mammals