HR: 15:30h
AN: NB44C-01 INVITED     [Abstracts]
TI: Seed Bank Contribution to Vascular Plant Richness on Temporary Floating Islands
AU: * Cherry, J A
EM: cherr002@bama.ua.edu
AF: University of Alabama, Department of Biological Sciences Box 870206, Tuscaloosa, AL 35487 United States
AB: Fluctuating water levels create opportunities for recruitment of new individuals from wetland seed banks. In this study, floating island formation functioned similarly to drawdowns in water level by creating patches of sediment that were less inundated than the surrounding, undisturbed deep-water marsh. To examine if and how seed banks contributed to temporary formation of distinct plant assemblages on these islands, field surveys of plant percent cover on and off of islands were conducted over two years, along with a controlled greenhouse experiment in which inundation was manipulated. Plant assemblages differed significantly on and off of floating islands. Floating-leaved perennials dominated undisturbed deep-water marsh, while emergent species dominated floating islands. Moreover, species richness was greater on islands than in the undisturbed deep-water marsh. Plant assemblages in the greenhouse experiment also differed among inundation treatments in a manner consistent with differences observed in field surveys. These results demonstrate that floating island formation temporarily altered levels of inundation favoring the germination of a more species-rich, emergent plant assemblage. Because these islands persisted long enough for several species to set seed, their formation may contribute to the maintenance of the seed bank and help maintain populations of otherwise rare species within the deep-water marsh.
DE: 1851 Plant ecology
DE: 1890 Wetlands
SC: North American Benthological Society [NB]
MN: 2005 Joint Assembly