Odocoileus virginianus (White-tailed deer) can impact the ecological integrity of eastern deciduous forests, ultimately modifying plant community composition and structure. However, the strength and nature of these impacts can depend on characteristics of the landscape. While many studies show that growth and survival of both herbaceous and woody plants are negatively affected by deer herbivory, less is known about the context dependencies of these relationships. In order to determine the effect of deer on plant community regeneration and structure across the landscape, exclusion plots were established near the edge and in the interior of two northern hardwood forests. Our experimental design included 40 10x10 m plots, half of which excluded deer and half of which were control plots (accessible to deer). Background deer abundance in the forest was approximately 8 individuals per km2. After six years of exclusion, we surveyed the plant communities within study plots to assess the impacts of deer on plant community composition.
Results/Conclusions
After six years of exclusion, deer presence and proximity to edge interacted to drive richness of nonnative plants, increasing richness in deer access edge plots relative to deer exclusion interior plots (Access:Edge, Shannon Index = 0.2500, Exclusion:Interior, Shannon Index= 0.1399). However, deer presence did not impact native plant richness, nor was there an impact on overall herbaceous or woody plant richness. Plant cover, however, was unaffected by deer presence or absence for either native or exotic plants. Our results indicate a limited impact of deer on plant community regeneration, contrasting with many studies that show dramatic and rapid plant response to deer exclusion. Sustainable control of deer density, combined with other environmental factors, may be maintaining the plant community in this region. Additional investigation is needed to evaluate the relationship between deer herbivory and plant community composition across forested landscapes.