SEED BANKS OF CAROLINA BAYS - POTENTIAL CONTRIBUTIONS FROM SURROUNDING LANDSCAPE VEGETATION

We used the seedling emergence method to evaluate the influence of the dominant vegetation (herbaceous, shrubby forested) and the surroundin g landscape on seed bank composition in seven Carolina bays. Landscape influence was evaluated indirectly by determining whether seed banks in wetlands close to clearcuts had more upland weedy species than thos e farther from clearcuts. Seed bank species composition and richness d iffered among forested, shrubby and herbaceous bays. DECORANA ordinati on identified a gradient of species composition from herbaceous bays, to shrubby bays, to forested bays. Bays near clearcuts had significant ly more upland weedy species in their seed banks, with bays 20 m from clearcuts containing 79% more weedy species on average than bays 100 m from clearcuts. Within a bay, drier vegetation zones had 2.4 times mo re weedy species than did deep water zones. These results illustrate t he potential contributions from surrounding landscape units to bay see d banks and highlight the need for further studies directly assessing the impact of adjacent clearcuts on bay vegetation dynamics.