A Quantitative Ecological Study on the Vegetation Cover of Burma Valley, Western Area, Saudi Arabia

Abstract

A total number of 45 plant species belonging to 21 families and 38 genera were identified. The dominant plant species in the study area were: Dipterygiacum gluacum, Tephrosia purpurea, Zygophyllum simplex, Fagonia indica, Senna alexandrina ,Fagonia crista, Panicum turgidum , Rhaza stricta and Acacia ehrenbergiana. The density of the vegetation cover in the study area differs from site to another according to the topography and rain fall rates. The densities of Dipterygiacum gluacum ,Tephrosia purpurea ,Zygophyllum simplex and Fagonia indica were associated with high frequency and high abundance. The density of Stiparagrostis hirtiglum was associated with low frequency and high abundance. Whereas the density of Senna alexandrina was associated with high frequency and low abundance. This reveals that these species are evenly distributed in the area. The densities of Fagonia crista, Panicum turgidum , Rhaza stricta and Acacia ehrenbergiana were associated with low frequency and low abundance. This explains that these species are not regularly distributed. Statistical analysis showed a positive association between two of the following species: Dipterygiacum gluacum and Zygophyllum simplex, Dipterygiacum gluacum and Fagonia indica, Tephrosia purpurea and Zygophyllum simplex, Tephrosia purpurea and Acacia ehrenbergiana. Tephrosia purpurea and Panicum turgidum, Zygophyllum simplex and Fagonia indica, Zygophyllum simplex and Rhaza stricta, Panicum turgidum and Rhaza stricta, Acacia ehrenbergiana and Panicum turgidum. However, negative associations were observed between each of the following: Dipterygiacum gluacum and Senna alexandrina, Dipterygiacum gluacum and Zygophyllum simplex, Tephrosia purpurea and Rhaza stricta, Zygophyllum simplex and Panicum turgidum. Fagonia indica and Panicum turgidum. The dominant species were found across the study area. These species are more suitable for rehabilitation of the study area, due to their adaptability to the environmental conditions. The present study reported the felling of woody species, heavy grazing and browsing. Particularly around water points in the study area. There is need for reseeding of woody species. The management of these plant species should conform to the ecological factors prevailing in the study area.