Floristic Composition of the Farasan Archipelago in Southern Red Sea and its Affinities to Phytogeographical Regions PDF

Keywords

Farasan Islands, floristic composition, phytogeography, Arabian Peninsula, SomaliaMasai, endemism.

Abstract

This Floristic affinities of the Angiosperm flora of Farasan Archipelago are analyzed. Phytogeographically, it is an interesting area due to its location between a flOlistically rich North East Africa and the Arabian Peninsula. As per the current estimates, 201 species of higher plants belonging to 49 families are present in an area of less than 600 km2 . Among these 2.S% are regional endemics and IS (7 .S%) species are, so far, not reported from any other parts of the Arabian Peninsula. The endangered flora of the archipelago is of conservation concern, which is poorly recognized, both nationally and internationally. Populations of some of the locally endangered species are represented by 100-S00 individuals distributed in less than S km2 . Among these Euphorbia collenetteae Al-Zahran and El-Karemy, an endemic species seen in limited numbers. The entire estimated degree of occurrence of this species is approximately less than 40 km2 , with the actual area of occupancy being less than 10 km2. Since the topography, climate and the overall vegetation of these islands are more or less similar to that of the southwestern coastal regions of the Arabian Peninsula and the area lies within the Somalia-Masai regional centre of endemism (phytogeographical region), the majority of species are of African origin. Yet, islands also contain a significant number of other species that shape the vegetation of the Tihama Region of Jizan (Jazan) Province in the mainland. A detailed analysis carried out on various life-forms shows that the highest percentage share of species (38.46%) is with the Somali-Masai phytogeographical zone, followed by Tropical African (2S .64%) and Saharo-Arabian (16.02%) phytogeographical zones.