Authors: Jonathan D Goode*, University of Alabama, Carson R Barefoor, University of Alabama , Justin L Hart, University of Alabama , Daniel C Dey, USDA Forest Service
Topics: Natural Resources, Physical Geography, Biogeography
Keywords: Forest ecology, disturbance, neighborhood, structural complexity, compositional diversity, Quercus
Session Type: Poster
Start / End Time: 8:00 AM / 9:40 AM
Room: Napoleon Foyer/Common St. Corridor, Sheraton, 3rd Floor
Presentation File: No File Uploaded
Stand structural complexity enhancement is an increasingly popular management objective, especially on public lands. Complex stand structures are hypothesized to support a relatively high degree of native forest diversity and be more resistant and resilient to disturbances. Relatively little is known about how discrete disturbance events affect structural complexity and compositional diversity in Quercus (oak)-dominated stands at fine spatial scales (i.e. neighborhoods). We collected data in a stand on the Sipsey Wilderness of William B. Bankhead National Forest in northern Alabama. We established 20 0.05 ha fixed radius plots to quantify live tree species composition and structure, and measured coarse woody debris. Trees were mapped on each plot to quantify overstory structural complexity and compositional diversity. The oldest Quercus dated to 1795, and the largest recruitment pulse occurred in the 1870s. The mean return interval for stand-wide disturbance was 38 years. Although we documented no relationships between disturbance frequency and compositional diversity at the neighborhood scale (0.05 ha), less frequent disturbance was associated with higher structural complexity (r2 = 0.258 p = 0.026) at the neighborhood scale. We suggest that localized disturbance increases species diversity and structural complexity, but these processes are manifest at the stand level and not at the neighborhood scale. We conclude that the spatial variability (i.e. size, shape, orientation, microsite conditions) is likely more influential on diversity and complexity than the temporal variation (frequency) of these processes at the neighborhood scale.