c 1998 Kluwer Academic Publishers. Printed in the Netherlands. Factors influencing male mating success in bur oak,

nation Application. Genotyping at DNA microsatellite loci identified pollen donors of a large sample of acorns and saplings in one stand of bur oak. The data were used to test if several character-istics of pollen donors were correlated with reproductive success. Male reproductive success could not be completely explained by any factor tested, including distance from maternal tree, direction of tree relative to maternal tree, size of tree, or genetic relatedness to maternal tree. Managers of seed orchards should consider that pollination contamination from distant sources may be extremely common and may not necessarily be confined to trees at the edge of the orchard. In general, simple models of wind pollination based on distance and direction should be avoided because they will not adequately predict gene flow patterns of male reproductive success. Abstract. Pollen donors of acorns and saplings in a stand of bur oak were identified by paternity exclusion using microsatellite genotype analysis. Here we examine the influence of several factors likely to affect reproductive success of males with wind-dispersed pollen, including distance of pollen donor from maternal tree, genetic relatedness of pollen dono