VEGETATION STRUCTURE AND PHYTOGEOGRAPHY OF JABAL SHAMS, AN ARID MOUNTAIN IN OMAN

The vegetation structure and phytogeography of Jabal Shams, an arid mountain in Oman, was studied using multivariate analysis. Using classification, four plant communities were delimited from 650 m to 2820 m altitude. Stand ordination showed that altitude had a strong influence on the structure of the vegetation. alpha-diversity of the plant species was greater in the two plant communities at lower altitudes (650-1480 m) than in the two plant communities at higher altitudes (1480-2820 m). Climate appeared to be most favourable for plant growth and diversity from 1000 m to 1480 m. The altitudinal pattern of plant diversity and growth on Jabal Shams may be proposed as a model for arid mountains in desert regions. Chamaephytes and hemicryptophytes were the dominant life-forms and there was a high diversity of growth-forms on the mountain. The computational structure and pattern of the vegetation showed that phytogeographically Jabal Shams was closely related to the mountainous regions of SW Iran and Baluchistan (SW Pakistan).