Abstract Detail

Floristics & Taxonomy

Alharbi, Samah [1].

A Phylogenetic Assessment of the Affinities of the Farasan Islands Flora, Red Sea.

The Southern Red Sea and its continental archipelagos are a global biodiversity hotspot. The Farasan Islands (Saudi Arabia) form the second-largest archipelago in the Red Sea and have the highest combined marine and terrestrial biological diversity in the basin, which is under threat of loss due to human activities and climate change. The floral diversity of the islands is of particular interest as it represents a transition point between the floristically rich North East Africa and western Asia. This includes well-preserved populations of regionally and nationally rare species, such as Avicennia marina, Rhizophora mucronata and Euphorbia collenetteae. Very few investigations have sought to explain the floristic relationships between the Farasan Islands and the mainlands. Scientific approaches have involved the comparison with regional floras and inferring the taxonomic distribution patterns of present taxa in the Farasan Islands. The analyses presented in this study used phylogenies and molecular dating to explore the Farasan flora’s phylogenetic affinities with the intention of discovering the timescale of colonisation events. This study is the most comprehensive phylogenetic study to be carried out on the Farasan Islands flora to date. It included ten plant angiosperm genera, which represent the islands’ main habitat types. Molecular work included the amplification and sequencing of 20 conventional DNA markers of chloroplasts and nuclear genomes. These data were obtained from 130 samples belong to the Farasan Islands and mainland species of Avicennia L., Convolvulus L., Cyperus L., Euphorbia L., Ficus L., Heliotropium L., Indigofera L., Rhizophora L., Suaeda Forssk. ex J.F.Gmel. and Tetraena Maxim. The originated data was then incorporated into the worldwide phylogenies of the targeted genera. The phylogenetic evidence showed that the Farasan Islands flora is recent, part of the Red Sea flora, and most of the species are probably more closely tied to the large species pool of adjacent Arabian flora. The islands’ populations are not isolated, and the very close phylogenetic links to the mainland populations suggest they might be acting as one population in an integrated area. This creates an important implication for the conservation of the islands’ biodiversity in that the planning for the conservation of Farasan endangered lineages needs to be integrated with conservation action on the mainland. The islands’ flora appears to have developed through a range of dispersal routes: overland dispersal via land bridges during the Pleistocene and transported by birds, sea currents, winds, and humans.

1 - Umm Al Qura University, Biology, Awaly, Mecca , 24381

continental archipelagos
The Red Sea islands
Islands flora.

Presentation Type: Poster Time and date to be determined
Abstract ID:37
Candidate for Awards:None

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