title: Long-distance seed dispersal in a metapopulation of Banksia hookeriana inferred from a population allocation analysis of amplified fragment length polymorphism data.
abstract: There is currently a poor understanding of the nature and extent of long-distance seed dispersal, largely due to the inherent difficulty of detection. New statistical approaches and molecular markers offer the potential to accurately address this issue. A log-likelihood population allocation test (AFLPOP) was applied to a plant metapopulation to characterize interpopulation seed dispersal. Banksia hookeriana is a fire-killed shrub, restricted to sandy dune crests in fire-prone shrublands of the Eneabba sandplain, southwest Australia. Population genetic variation was assessed for 221 individuals sampled from 21 adjacent dune-crest populations of B. hookeriana using amplified fragment length polymorphism. Genetic diversity was high, with 175 of 183 (96%) amplified fragment length polymorphism markers polymorphic. Of the total genetic diversity, 8% was partitioned among populations by amova and FST. There was no relationship between genetic diversity within populations and population demographic parameters such as population size and sample size. A population allocation test on these data unambiguously assigned 177 of 221 (80.1%) individuals to a single population. Of these, 171 (77.4% of total) were assigned to the population from which they were sampled and 6 (2.7% of total) were assigned to a known population other than the one from which they were sampled. A further 9 (4.1% of total) were assigned to outside the sampled metapopulation area, and 35 individuals (15.8%) could not be assigned unambiguously to any particular population. These results suggest that both the extent [15 of 221 (6.8%) individuals originating from a population other than the one in which they occur] and distance (1.6 to > 2.5 km), of seed dispersal between dune-crest populations is greater than expected from previous studies. The extent of long-distance interpopulation seed dispersal observed provides a basis for explaining the survival of populations of the fire-killed B. hookeriana in a landscape experiencing frequent fire, where local extinctions and recolonizations may be a regular occurrence.
authors.affiliation: Department of Environmental Biology, Curtin University of Technology, Perth, Australia.
authors.forename: Tianhua
authors.initials: T
authors.lastname: He
authors.forename: Siegfried L
authors.initials: SL
authors.lastname: Krauss
authors.forename: Byron B
authors.initials: BB
authors.lastname: Lamont
authors.forename: Ben P
authors.initials: BP
authors.lastname: Miller
authors.forename: Neal J
authors.initials: NJ
authors.lastname: Enright
mesh_terms: D003710:Demography; D005390:Fires; D014644:Genetic Variation; D005828:Genetics, Population; D005843:Geography; D008954:Models, Biological; D012150:Polymorphism, Restriction Fragment Length; D011157:Population Dynamics; D039105:Proteaceae / Q000235:genetics* / Q000502:physiology; D012639:Seeds / Q000502:physiology*; D014904:Western Australia