PARENT SESSION
Poster Session #30: Disturbance Ecology II.
Tuesday, August 6. Presentation from 5:00 PM to 6:30 PM. Exhibit Hall B & C, TCC

The impact of a major canopy disturbance event on the long-term dynamics of North Carolina Piedmont forests.

XI, WEIMIN^*,1, PEET, ROBERT¹, URBAN, DEAN², ¹ The University of North Carolina at Chapel Hill, Chapel Hill, NC² Duke University, Durham, NC

ABSTRACT- Large, infrequent disturbances have been hypothesized to have profound effects on forest vegetation and specifically to increase tree diversity through enhanced establishment of tree seedlings driven by increased resource availability. However, a definitive test of this hypothesis requires detailed, rarely available times-series data spanning the disturbance event. In 1996 Hurricane Fran significantly damaged the forest canopy above many long-term tree seedling census plots in the Duke Forest of Piedmont North Carolina. We present a preliminary analysis of changes in the diversity of woody seedlings during an interval lasting from 15 years prior to Fran until 5 years post-Fran. Data were collected from 27 seedling transects (50x1 m in size) where individual seedling stems have been censused annually (13 of 27) or nearly annually since 1978. The plots experienced an immediate sharp drop in seedling density and species richness caused by direct windstorm damage. This was followed by a rapid rebound in stem density and more gradual recovery and enhancement in species richness and diversity. Our case study supports the hypothesis that canopy disturbances can promote local species diversity. In addition, comparison of responses across the multiple plots shows that these disturbance-induced changes must be viewed in the context of variation in species composition resulting from differences in habitat and stand history.

KEY WORDS: species diversity, seedling recruitment, Hurricane impact, forest dynamics