Sapling Strategies and Gap Partitioning in Canopy Gaps of A Successional Forest in East Tennessee

Canopy gaps in a successional forest in East Tennessee were studied to determine the role of gaps in plant succession, sapling growth and mortality, and sapling colonization strategies. The possibility of niche partitioning within gaps was examined. Ten gaps (64-309 m2 , mean=186 m2 ) and four closed canopy plots (200 m2 each) were surveyed by identifying and locating all trees, measuring terminal growth of saplings (n=933), and measuring diameter at breast height (D.B.H.) of trees > 3 m tall (n=S04). The present canopy is dominated by oaks (Quercus spp.), pines (Pinus spp.), tulip tree (Liriodendron tulipifera L.), and beech (Fagus grandifolia Ehrh.), while dominant saplings are beech, red maple (Acer rubrum L.), and sugar maple (A. saccharum Marsh.). Sapling composition in gaps indicates that the current canopy will be replaced by a forest dominated by beech and maple. All three dominant sapling species showed significantly greater extensional growth in gaps (p

Growth of individuals in gaps is highly variable, with microsite and genetic differences creating conditions that allow colonization by many species. Little evidence of niche partitioning within gaps was observed. Forest communities in East Tennessee may not have maintained a constant composition or disturbance regime for a long enough period of time for such fine niche partitioning to evolve.