A phylogeographic break in a South African coastal saltmarsh macrophyte, Juncus kraussii

Abstract

Many species, predominantly marine, along the coast of South Africa have divergent lineages that are geographically separated. In this study, we explored the phylogeographic pattern of the salt marsh plant species, Juncus kraussii, sampled from estuaries along the west, south and east coasts. From these samples, five haplotypes were identified from the chloroplast rps16 intron. A phylogeographic break was found along the south coast within the warm temperate coastal biogeographic zone. We suggest that this break may have been driven by the rapid shifts in shoreline along the south coast in response to Pleistocene climate cycles. The genetic structuring observed in this study points to hidden biodiversity, at the genetic level, of salt marsh plants and this needs to be explored to aid conservation planning in terms of priority protection and management.