Sparse Buried Seed Bank in a Southern Appalachian Oak Forest: Implications for Succession

Abstract

-Samples of leaf litter, humus and surface soil were collected from sites on six steep NE-facing slopes to determine the density and species composition of the buried seed bank on Brush Mountain (Jefferson National Forest, Montgomery Co., Va.) and its potential contribution to postdisturbance forest regeneration. An average of only 0.43 seeds/ m2 was found at the sites, with significantly more seeds occurring in the humus layer than either the leaf litter or soil. Seeds of forest herbs were more common than those of forest trees, forest shrubs or even ruderals. There were also differences in seed density and species composition among sites. These results were unexpected, and probably due to the cumulative long-term effects of a variety of factors including: (1) the lack of past cultivation; (2) past low-intensity ground fires; (3) the scarcity of nearby sources of ruderal and early-successional seeds, and (4) the inherently short longevities of seeds of forest species. The sparse seed bank, particularly the virtual absence of seeds of early successional species, indicates that succession should be strongly dependent upon vegetative reproduction and postdisturbance seed dispersal.