Main FindingsAssessment of the results obtained from the different studies conducted along these climatic transects clearly indicate that there are two transition zones: one from shrubs to dwarf shrub- dominated areas, corresponding to the northern/ western extent of the 200 mm/year Isoline (Figure 1), and another from dwarf shrub-dominated to bare terrain corresponding to the southern/ eastern extent of the 400-mm/year Isoline (Figure 1).
The Non-linear mode of vegetation biomass change with precipitation was generalized. This Non-linearity seems to be weak where there is relatively moderate human disturbance to the natural vegetation: such levels of disturbance characterized the Mediterranean regions for many centuries. However, when the accumulated disturbances increase, such as probably was the case in the Judean transect (West to East) , the non-linearity increases while mainly reducing the dwarf shrub cover. Comparison of the biomass derived for cover compositions from the phytogeographical maps and those from the remote sensing data indicated that in the Judean transect (West to East) the disturbance is hypothetically very high also in the most humid site: in Givaat Yearim, where it reaches almost half of the biomass it should produce. The generalized hypothetical model represented in equation (1) may facilitate assessment of disturbance levels; however, this model needs to be further assessed in other sites across the Mediterranean.
These Studies benefited from the generous support provided by the German – Israeli BMBF Grant
Scheme, by the Jewish National Fund, and the grants provided to the MEDALUS team the framework of the European Research Programs 3&4
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Climatic Gradients 
