Threatened halophytic communities on sandy coasts of three Caribbean islands

Three tropical islands — Trinidad, Dominica and St. Lucia — in the British Caribbean were surveyed for location of coastal herbaceous halophytic plant communities native to upper, intertidal sandy beaches. Comparisons of earlier and later drawn topographical maps displayed marked urban expansion indicating the disappearance of native beach vegetation. Hierarchial cluster analysis revealed marked similarities among sites on these islands. Studies of alpha and gamma diversity of the few, viable communities located along back beaches revealed that, like temperate sandy communities, these communities were generally characterized by a small number of perennial halophytic species. At most locations, the community was dominated by only one species — Ipomea pes-caprae — accompanied by a few sub-dominant species. Governments of these islands should consider preserving the few remaining native beach plant communities for future scientific studies.