| Postelsia palmaeformis Ruprecht is an intertidal kelp that occurs in the mid- to high-intertidal on rocky coastlines from central California, USA to British Columbia, CA. P. palmaeformis has an alternation of generations life history with an annual sporophyte that occurs in the field between May and October. The ecology of P. palmaeformis is well studied and suggests that spores have short-range dispersal, generally from 3–5 m from parent sporophytes. This study followed the population dynamics of P. palmaeformis at Fogarty Creek, Oregon from 1997–2001 and examined population genetic structure using microsatellite loci. Population size varied dramatically from fewer than 500 sporophytes in 1998 to greater than 18,000 in 2001. Estimators of Wright's F-statistics indicated significant population genetic structure with limited gene flow among distinct subpopulations. Further, a significant deficiency of heterozygotes, along with data on a newly founded subpopulation in 2000, suggests that self-fertilization may be common in this species. |
