Seed banks have the potential to buffer populations against environmental uncertainty and to serve as reservoirs of genetic variation. From the perspective of the metapopulation, these dormant propagule pools can lower extinction rates for population fragments by providing a means of maintaining demes that does not require long distance seed dispersal. This presentation provides previously unreported data on the effects of 2.5 to 3.5 yr burial on the survival and genetic composition of white campion (Silene latifolia) seed banks. We encased seeds in porous fabric packets, buried them to a depth of 5 cm at 5 randomly selected locations at each of two sites, and exhumed samples 2.5 and 3.5 yr later. An average of 41% of seeds survived 3.5 yr of burial, and germination during burial accounted for almost all losses from the seed bank. Seeds that remained ungerminated during burial showed 87% survival. Percent germination during burial varied significantly among burial locations within sites after both 2.5 and 3.5 yr of burial, but differed significantly between the two sites only after burial for 3.5 yr. Variation in percent germination during burial failed to correlate significantly with percent soil moisture. Comparison of the seeds that survived 2.5 yr burial with the original seed crop indicates that survival in the seed bank was neutral with respect to sex, heterozygosity, and genotype at 7 isozyme loci. Data regarding the effects of burial for 3.5 yr on the genetic composition of the seed bank will be presented. The results collected to date suggest that dormant seed banks may influence white campion metapopulation dynamics and that these seed banks serve as relatively unselective reservoirs of genetic variation.

Key words: metapopulation, seed banks, seed ecology, Silene latifolia, white campion