Vegetation ecology and diversity of six Kuwait Islands: factors influence on species composition and richness

Kuwait lies at the Northwest corner of the Arabian Gulf, and its eastern coast comprises parallel arcs of nine islands. The present study dealt with vegetation ecology and species diversity analysis of six uninhabited islands, except Failaka, Warba, and Bubiyan islands, with varied sizes of area ranging from 0.5 to 863 km 2 . A total of 70 species of flowering plants (60% annuals and 40% perennials), belonging to 32 families, were collected from the islands and their list is given. The main phytogeographical category was represented by Saharo-Arabian elements followed by the Irano-Turanian and Mediterranean elements. The vegetation type is essentially halophytic with widespread annuals. Six associations were identified with the application of TWINSPAN, DCA, and CCA programs. They were named after the characteristic species as follows: VG I: Polycarpon tetraphyllum , VG II: Zygophyllum qatarense, VG III: Emex spinosa , VG IV: Seidlitzia rosmarinus , VG V: Malva parviflora - Salsola imbricata, and VG VI: Suaeda aegyptiaca . These associations were compared with the plant communities of Kuwait and neighboring countries of Gulf region. The soil characteristic factors alkalinity, moisture, soil texture, and minerals showed the best correlation with the distribution of the associations. Significant differences between island area, species diversity indices, organic matter, and minerals contents of the islands were observed. Flora of these uninhabited islands with un-grazed plants constituted about 37% of the flora of the mainland of Kuwait and their valuable elements warrant prioritized conservation measures.