Microevolution and Clone Structure in Spartina patens.

Analysis of the clone structures within a population of Spartina patens reveals considerable adaptive genetic divergence among adjacent dune, swale, and marsh sites. The dune subpopulation includes a small number of frequently encountered, spatially isolated clones that follow microtopography and have high reproductive output and colonizing potential. The marsh subpopulation consists of a large number of infrequent interdigitating clones with high vegetative biomass and competitive success. The swale subpopulation is generally intermediate for these traits.