Abstract

Mediterranean-type environments share unique climatic pattern with a cool wet winter and a hot dry summer (Koppen 1900), constituting the core of what we call the Mediterranean climate. These climatic conditions can be coarsely considered as a transition between dry tropical and temperate climates, with an occurrence of a distinct summer drought. These conditions occur on the west coasts of all continents between latitudes 30° and 45°, because of very general reasons of air circulation as the dry subtropical high pressure cells move poleward in the warm season blocking the entry of midlatitude storm. One of the main corollary of this approach is to clearly define Mediterranean regions as zonal ones and to exclude limited geographical definitions considering only the Mediterranean Sea (Joffre and Rambal 2002). It is important to note that the Mediterranean climate is very recent in geological terms and first appeared approximately 3.2 million years ago during the Pliocene. Mediterranean climates have attained their greatest extent at present.