Vegetation analysis of Wadi Al-Jufair, a hyper-arid region in Najd, Saudi Arabia

摘要

Wadi Al-Jufair, a tributary of Wadi Nisah, is one of the important wadis of Najd region (Saudi Arabia) sheltering a rich diversity of higher plants. The study area is extended into approximately 15km^2 encompassing the commonest geomorphological features encountered in desert wadis. The wadi supports several rare plants, including Maerua crassifolia Forssk., a regionally endangered tree, and Acacia oerfota (Forssk.) Schweinf., a rare shrub with restricted distribution. The present study aims to analyze the vegetation of wadi Al-Jufair and to propose its designation as an important plant reserve. The vegetation type is fundamentally of chamaephytic nature with some phanerophytes, and distinguished into associations where the dominant perennial species give the permanent character of plant cover in each habitat. Four vegetation groups were identified after the application of TWINSPAN, DCA and CCA programs and named after the characteristic species as follows: Lycium shawii; Acacia oerfota; Acacia raddiana -Rhazya stricta and Artemisia monosperma. These plant associations and speciation of Wadi Jufair demonstrate significant variation in soil texture, moisture, organic matter, pH, EC, and minerals.