West Saharan Montane Xeric Woodlands - Setting

Setting

The Sahara is a vast desert, stretching across northern Africa from the Atlantic Ocean to the Red Sea. Some mountains (Ahaggar, Tassili n'Ajjer, Tibesti, Aïr) rise up from the desert and receive more rainfall and mostly present slightly cooler summer temperatures. These highlands support dry woodlands and shrublands distinct from the hot dry desert lowlands.

This ecoregion has an area of 258,100 km2 (99,700 sq mi). The boundaries for the largest part of this ecoregion, which includes the Tassili n'Ajjer Ahaggar and Aïr (or Azbine) massifs, follow the 'regs,' 'hamadas' and 'wadis' above the 1000 m contour. This covers a good part of southeast Algeria. These areas reach almost 3000 meters in altitude. Additional areas further south were included within this ecoregion, including the Aïr ou Azbine in northern Niger, Dhar Adrar in Mauritania, and Adrar des Iforas in Mali and Algeria, using the 500 m-elevation contour.

The mountains of the West Saharan Montane Xeric Woodland ecoregion are found within the Sahara Desert and are predominantly of volcanic origin. They rise from the surrounding flat desert landscape or sand dunes and create islands of moister habitat (guelta) which support flora and fauna. The most important area is the Tassili n'Ajjer Plateau, an outlier of the Ahaggar Mountains in Algeria which supports some near-endemic species and some globally threatened antelopes. The highest point of these mountains is 3003 meters (Mount Tahat).

Winters are quite rigorous, with amplitude in temperature over 20°C. Day temperatures may be over 20°C while nights are freezing. In summer, days are very hot, though less than in central Sahara. Rainfall is rare and sporadic.