Cycad biodiversity in the Bahamas Archipelago and conservation genetics of the threatenedZamia lucayana(Zamiaceae)

A conservation assessment for the three cycad species native to the Bahamas Islands is presented. Results are based on field surveys on all islands where these species occur.Zamia angustifoliais native to Eleuthera,Zamia integrifoliais native to Abaco, Andros, Eleuthera, Grand Bahama and New Providence, andZamia lucayanais endemic to Long Island.Z. angustifoliais of the highest conservation concern because of the small number of adult plants, its restricted distribution and the extensive development occurring within its habitat.Z. integrifoliaalso has a restricted distribution on Eleuthera and Grand Bahama and, although threatened by urban development in New Providence, it is relatively common on Abaco and Andros.Z. lucayanacomprises three populations within a narrow strip of land of c. 1 km2; we propose a reassignment of its current conservation status from Endangered to Critically Endangered. We assessed the genetic structure ofZ. lucayanabased on 15 polymorphic microsatellite DNA loci; this indicated that the three known populations should be considered a single management unit. However, the high number of private alleles suggests that genetic drift, indicative of recent fragmentation, is progressing. We propose in situ conservation strategies, and we also collected germplasm from a total of 24 populations of these three cycad species, for ex situ conservation.