Conservation genetics and biogeography of the Caribbean pine (Pinus caribaea var. bahamensis) in the Bahaman archipelago

• Main Author: Sanchez, Michele
• Published: Birkbeck (University of London) 2012
• Subjects: 585
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.571281

The Bahaman archipelago contains large expanses of pine forests, where the endemic Caribbean pine Pinus caribaea var. bahamensis is the dominant species. This pine forest ecosystem is rich in species and also a valuable resource for the local economy. Small areas of old-growth forest still remain in the Turks and Caicos islands (TCI) and in some of the islands in the Bahamas; despite on-going severe infestation by pine tortoise scale insect Toumeyella parvicornis and high pine mortality in the former and intensive past commercial logging activities in the latter. For the first time integrated research on the genetics, morphology, ecology and biogeography of this variety was carried out throughout its whole distribution range. Past and present forest areas were mapped using historical physical maps and modern satellite imagery, showing forest loss due to urbanisation, pests and storm surges and expansions resulting mainly from dry-season human induced fires. Population genetic analysis using plastid and nuclear microsatellites revealed high ancient gene flow and recent genetic distance between populations of the Bahamas and the TCI; in addition to genetic structure within regions. Morphological differences were also observed and discussed. The variety showed high individual genetic and morphological variance and high plasticity. Despite the observation of good forest regeneration in normal circumstances, stochastic events did cause severe reductions in forest area and effective population size. A predominantly random and outcrossing breeding system was also inferred from the data, despite detection of some inbreeding in the smaller populations. Suggestions for the future conservation and management of the species included fire management and the creation or extension of in-situ conservation areas and ex-situ collections.