Abstract
The present study aimed to identify the communities with Brassica tournefortii Gouan in Al-Jouf areas in northern Saudi Arabia, to determine the ecological amplitude of this species and soil factors controlling its distribution. The plant communities dominated by B. tournefortii were investigated in fifteen localities through 15 plots. In each plot the present species were recorded. Data were treated by multivariate analyses. Soils of each community were analyzed using eleven physico-chemical parameters. Analysis of variance and correlation coefficient were performed based on R software package. Three vegetation types have been recognized by the applications of Past program classification. 83 species have been observed. Canonical correspondence analysis demonstrated that soil parameters contributed significantly to the distribution of species. B. tournefortii dominated the communities in newly reclaimed lands, where it survived in sandy habitats. It is characterized by high competition with both cultivated plants and associated weeds. This paper represents a study of the diversity of B. tournefortii communities in Arabia Saudi.