SPATIAL AND GENETIC-STRUCTURE OF 2 SANDHILLS OAKS - QUERCUS LAEVIS AND QUERCUS-MARGARETTA (FAGACEAE)

Quercus laevis Walt. (turkey oak) and Q. margaretta Ashe (scrubby post oak) are important scrub oaks in the sandhills forest communities of the Coastal Plain of the southeastern United States. We used allozyme loci and Ripley's L-statistics to examine clonal structure and spatial dispersion in these species. Q. laevis greater than 1.5 m in height were randomly dispersed on a scale of 0-40 m; smaller individuals (< 1.5 m) were slightly clustered on a scale of 0-12 m. Larger individuals separated by less than or equal to 1 m had 15% probability of being ramets of the same clone. Q. margaretta showed strong clustering on a scale of 0-20 m. Stems separated by less than or equal to 1 m had a 71% probability of being ramets of the same clone. Clonal offspring were strongly clustered about the presumed clonal parent: 50% fell within 0.50 m of this individual. Simulation modeling and direct comparison of adult and juvenile genotypes indicated that acorns are dispersed on a scale of tens of meters for both species, suggesting animal vectors such as squirrels or blue jays.