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Vegetation in north-central Saudi Arabia

1986; Elsevier BV; Volume: 10; Issue: 3 Linguagem: Inglês

10.1016/s0140-1963(18)31237-0

1095-922X

E Schulz, John W. Whitney,

Ecology and Vegetation Dynamics Studies

Vegetation forms a scanty but diffuse, permanent shrub cover on the arid landscape of north-central Saudi Arabia. Floristically, the area is dominated by the large transition zone between the Mediterranean and saharo-sindian regions. In general, vegetation types in north-central Saudi Arabia are dominated by Mediterranean flora, except on the Arabian Shield peneplains, where the vegetation is typical of the saharo-sindian deserts. Vegetation distribution on the landscape correlates with six general landscape units; however, our information on floristic composition and seasonal changes is not complete enough to create phytosociological units. Rocky, high relief areas support shrub and tree vegetation with tufted grasses and herbs; Rhus tripartita and Cymbopogon are common. Surrounding sandy pediments are covered by chenopods; primarily Anabasis and Hammada, along with Fagonia, Astragalus and many herbs. Wadis in the mountains support Acacia, Ochradenus, Artemisia, and Ballota, and wadis on the pediments support both Acacia and Lycium. Rhanterium, Fagonia and Astragalus are the dominant shrubs of the extensive serir plains of the Arabian Shield. Anabasis and Hammada are common on sandy plains, and the large, sandy wadis on the Arabian Shield support an Acacia–Panicum vegetation. Along the margins of playas located on the plains, the density of Rhanterium increases and Artemisia is present. The sand seas support a diffuse plant cover of shrubs and tufted grasses. Both the number of species and plant density are greater on dunes than on the bedrock plains. Cyperaceae, Artemisia monosperma, Calligonum comosum, Stipagrostis drarii and Cyperus conglomeratus are the most common plants. Achab floras are common at the foot of dunes following rainstorms, and Plantago, Monosonia, Stipagrostis plumosa, Moltkiopsis, and Filago are among the common herbs. A sparse cover of Helianthum and Fagonia is found on lake beds and duricrusts that are sometimes present in the interdunal depressions.