Recovery of the Herb Layer in a Southern Appalachian Forest Following Chronic Herbivory by Deer (Odocoileus virginianus)

Abstract

ABSTRACT The high abundance of ungulates in temperate zone forests is affecting biodiversity and ecosystem functions worldwide. A randomized, replicated experiment excluded white-tailed deer, Odocoileus virginianus, from six 10 × 10 m fenced plots for 10 years; six unfenced plots were maintained as controls. The effects of chronic herbivory were assayed by comparisons using the mean responses of ground-level vegetation in nine subplots within each of the 12 plots. Deer had a small effect on species richness but a strong effect on species prevalence, cover, and biomass, with repeatable differences in the responses of taxa to the treatments. Graminoids were favored in control plots, many other monocots and several dicots were favored in fenced plots, and parasitic plants and chemically defended herbs showed few detectable responses to fencing. The height of the vegetation represented by the shrub Vaccinium erythrocarpum and the herb Medeola virginiana was significantly taller in fenced than in control plot...