Several components of diversity (ecological, taxonomic, chorological and morphologicalfunctional) were studied in the woody vegetation of the cork oak forests in the northern Straits of Gibraltar Region, and their relationship to the two main environmental gradients (one mainly climatic-precipitation, fog-and another secondary related to the disturbance and hydric stress associated with hillslope orientation). An inventory of the woody species and their cover measure was carried out on 94 plots. The relationship between the components of diversity and the main environmental gradients was analysed by means of regression analysis. Decreases of species richness, Shannon diversity index, Western Mediterranean species cover, percentage of endemism and the share of the Herrera Syndrome I in diversity were related to the increase of the precipitation and the fog. However, the cover and percentage of species of the Circum-Mediterranean and Mediterranean-Eurosiberian chorological groups increase with the precipitation and the fog. Disturbance and hydric stress associated with hillslope orientation, have a negative effect on specific richness of the Mediterranean-Eurosiberian chorological group and taxonomic singularity, but its have a positive effect on the share of the Herrera Syndrome I in diversity. The number of edaphic endemisms is associated mainly with disturbance. In the cork forests does not exist an inverse relationship between the number of endemisms and floristic richness, as it happens in other Mediterranean areas. It has suggested that this pattern is due to effect of competitive exclusion associated with disturbance in vegetation on relatively fertile substrate.