Desert rocks as plant refugia in the Near East

The outcrops of smooth-faced rocks in Near Eastern deserts function as refu gia for plants that do not fit the present local climate. They have survive d in the area from periods when the continuous extensions of the moister cl imate enabled their penetration from the Mediterranean zone. The largest Me diterranean enclave in Near Eastern deserts and steppes is the sandstone an d limestone outcrops at the upper escarpments of the southwestern Jordanian plateau, between At Tafila and Ras en Naqb, including the famous Petra and Wadi Dana. Hundreds of Mediterranean relict species and dozens of endemic species coexist with steppe and desert species in the crevices of these roc ks. In this article I discuss the ecology, phytogeography, and distribution of this special habitat in Jordan, the Sinai, and Israel; and I compare th e influence on past and present floras of climatic oscillations during the Pleistocene and Holocene in the Near East and Africa.