干旱区生态环境知识资源中心

In order to determine the boundary between the Mediterranean and Sahara(Gobi areas of the Palearctic, a proposed transitional zone between them was studied, which was limited by the northern and western boundaries of the ranges of the desert lizards (Acanthodactylus, Eremias, and Trapelus), which penetrate far to the north and east, on the one hand, and by the southern and eastern boundaries of the range of the Mediterranean genus Lacerta on the other. According to similarity of the ranges and origin, all species occurring within these limits were assigned to four groups: desert species (their ranges extend only east and south of the zone), Mediterranean species (their ranges extend only west and north of the zone), widespread species (their ranges extend on all sides of the zone), and endemic species of the zone. A territory was assigned to one of the faunistic areas based on the predominance (50% or more of the number of species) of Mediterranean or desert species. The regions where none of the above groups exceeded the 50% level were assigned to the transitional zone.