Long‐distance seed dispersal in a metapopulation ofBanksia hookerianainferred from a population allocation analysis of amplified fragment length polymorphism data

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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 hookerianais 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 ofB. hookerianausing 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 byamovaandFST. 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‐killedB. hookerianain a landscape experiencing frequent fire, where local extinctions and recolonizations may be a regular occurrence.