Affiliation: College of Arts and Sciences, Department of Biology
Herb and sapling vegetation data from permanent plots in Duke Forest were collected and compared with vegetation data from 1977 and 2000 to evaluate compositional change. Declines in herb layer cover and richness indicate likely impacts from white-tailed deer herbivory. Oak regeneration has slowed, and the historical oak-hickory forest may be replaced by dominant maple and beech. The average annual rate of herb layer change is consistently higher for 2000 - 2010 than for 1977 - 2000, indicating acceleration in vegetation shifts, with deer herbivory as a possible contribution. Projections of the 2000 and 2010 successional pine herb layer composition based on a space-for-time substitution of the 1977 data indicate substantial variation from the observed data. Furthermore, MRPP tests indicate grouping of successional pine plots by sampling year and not by age. These factors, combined with the increasing rate of change, suggest that environmental influences may overshadow successional change.