The Soil Seed Bank of Granite Outcrop Plant Communities

The seed bank of plant communities representing different stages in a primary sere was examined. These communities occupy soil-filled depressions (soil islands) which are formed on some granite exposures in southeastern United States. Three of the four stages which compose the sere were considered in the present study. Of 35 taxa identified in the seed banks, 11 revealed significant differences (P = 0.05) along the successional, or the stress gradient. Seed bank richness and diversity increased along the successional gradient, similarly to vegetation richness and diversity. There was a significant positive association (P = <0.001) between species presence in the vegetation and presence in the seed bank, and the degree of this association increased from earlier to later successional stages.