eremian zone

The term "Eremian" refers to a geographical division of the Palaearctic region. This zone encompasses northern Africa, northern Arabia, and desert areas across Asia. The word originates from the Greek term "eremia," meaning solitude or desert.1

Deserts, which characterize the Eremian zone, are defined by a significant lack of available moisture for plants. This scarcity results from an imbalance between precipitation and evapotranspiration, further intensified by irregular rainfall, low humidity, high temperatures, and wind. While average annual precipitation can vary, most deserts receive less than 400 millimeters (about 16 inches) of rain annually. These arid conditions are largely due to atmospheric circulation patterns, particularly the Hadley cell, which causes dry air to descend in subtropical regions.2