PRELIMINARY ANALYSING OF PLANT DIVERSITY OF HIGH ALTITUDE AREA OF ALBAHA REGION, SAUDI ARABIA

The study on the floristic analysis and plant diversity was carried out during the years 2014 and 2016 covering the high altitudinal plateau between 1900 to 2475 mater above sea level (m. a. s. l.) of Al Baha region, Saudi Arabia. This attempt was made, to document the density; frequency and diversity of plant species existing in different land forms, to identify the priorities of conservation and rehabilitation for the least occurrence plant species and Juniperus procera and Acacia origena habitats in the future plan. Random quadrat methods of 25*25 m were laid out in various parts of the region to reach the total of 73 sample plots. The data was analyzed using different ecological indices and tools. The out come of the analyzed data showed a total of 187 plant species belonging to 147 genera and 67 families, in which 3 are endemic to Arabian Peninsula and one is endemic to Saudi Arabia. Hyparrhenia hirta, Achillea biebersteinii, Cynodon dactylon, Themeda triandra Juniperus procera and Eragrostis papposa have the highest density per hectare with a value of 226, 176, 167, 134, 116 and 107 respectively. Frequency of plant species showed different trend of plant arrangement in different sample plots unlike the density. For instance Juniperus procera, Acacia origena, Dodonaea viscose, Psiadia punctulata and Sageretia thea have more frequency with a value of 0.86, 0.67, 0.47, 0.45 and 0.44 respectively. The dominant vegetation structure is a woodland dominated by Juniperus procera and Acacia origena and grassland dominated by Hyparrhenia hirta and Themeda triandra. Average tree cover is 25%, shrub cover is 17% and herbaceous cover is 36% with an average of 77% vegetation cover.