ABSTRACT
The Middle East is composed of a mosaic of often widely differing environments. In the northern part of the region, through Turkey and Iran, there are ranges of high mountains with crestlines up to 4000 m in height enclosing the high plateau regions of Anatolia and central Iran. In winter temperatures fall well below freezing, and snowfall often occurs associated with eastward-moving low-pressure systems. In contrast, the summers are nearly everywhere hot and dry. Further south in the Arabian peninsula and North Africa the mountains give way to a landscape of plains and plateaux, and here one finds the sand seas of the Rub al Khali and the Western Desert of Egypt. All of this region is characterized by low annual precipitation totals and hot summer temperatures; biological productivity is almost everywhere low.
