SOIL SEED BANK STRUCTURE AND COMPOSITION IN FLORIDA SAND PINE SCRUB

This study characterized a soil seed bank from which herbaceous and pa rtly woody species (hereafter, ''herbaceous plants'') may recover afte r fire in Florida sand pine scrub. Abundances and spatial distribution s of seeds in the soil and of adult plants were quantified in three si tes burned 1 or 2 yr before data collection, and in five sites unburne d for at least 40 yr. Median density of germinants from soil samples w as 20 seeds/m(2), with 10 taxa represented. Seed bank densities were n ot different between recently burned and long unburned sites. Percent cover of grasses and sedges did not differ between burned and long unb urned sites, but stem densities of dicotyledonous herbaceous plants we re lower in long unburned sites. The soil seed bank in sand pine scrub has three components, based on patterns of seed and conspecific adult occurrence in samples-monocotyledonous perennials with both seeds and adults present, ''weedy'' species with only seeds present, and specie s with poor seed dispersal with only seeds present.