Mediterranean Basin
In biogeography, the Mediterranean Basin (/ˌmɛdɪtəˈreɪniən/ MED-ih-tə-RAY-nee-ən), also known as the Mediterranean Region or sometimes Mediterranea, is the region of lands around the Mediterranean Sea that have mostly a Mediterranean climate, with mild to cool, rainy winters and warm to hot, dry summers, which supports characteristic Mediterranean forests, woodlands, and scrub vegetation. It was a very important part of Mediterranean civilizations.
"Mediterranean Region" redirects here. For other uses, see Mediterranean Region (disambiguation).Geology and paleoclimatology[edit]
The Mediterranean Basin was shaped by the ancient collision of the northward-moving African–Arabian continent with the stable Eurasian continent. As Africa–Arabia moved north, it closed the former Tethys Sea, which formerly separated Eurasia from the ancient super continent of Gondwana, of which Africa was part. At about the same time, 170 mya in the Jurassic period, a small Neotethys ocean basin formed shortly before the Tethys Sea was closed at the eastern end. The collision pushed up a vast system of mountains, extending from the Pyrenees in Spain to the Zagros Mountains in Iran. This episode of mountain building, known as the Alpine orogeny, occurred mostly during the Oligocene (34 to 23 million years ago (mya)) and Miocene (23 to 5.3 mya) epochs. The Neotethys became larger during these collisions and associated folding and subduction.
About 6 mya during the late Miocene, the Mediterranean was closed at its western end by drifting Africa, which caused the entire sea to evaporate. There followed several (debated) episodes of sea drawdown and re-flooding known as the Messinian Salinity Crisis, which ended when the Atlantic last re-flooded the basin at the end of the Miocene.[6] Recent research has suggested that a desiccation-flooding cycle may have repeated several times [7][8] during the last 630,000 years of the Miocene epoch, which could explain several events of large amounts of salt deposition. Recent studies, however, show that repeated desiccation and re-flooding is unlikely from a geodynamic point of view.[9][10]
The end of the Miocene also marked a change in the Mediterranean Basin's climate. Fossil evidence shows that the Mediterranean Basin had a relatively humid subtropical climate with summer rainfall during the Miocene, which supported laurel forests. The shift to a Mediterranean climate occurred within the last 3.2–2.8 million years, during the Pliocene epoch, as summer rainfall decreased. The subtropical laurel forests retreated, although they persisted on the islands of Macaronesia off the Atlantic coast of Iberia and North Africa, and the present Mediterranean vegetation evolved, dominated by coniferous trees and sclerophyllous trees and shrubs, with small, hard, waxy leaves that prevent moisture loss in the dry summers. Much of these forests and shrublands have been altered beyond recognition by thousands of years of human habitation. There are now very few relatively intact natural areas in what was once a heavily wooded region.
Phytogeographically, the Mediterranean Basin together with the nearby Atlantic coast, the Mediterranean woodlands and forests and Mediterranean dry woodlands and steppe of North Africa, the Black Sea coast of northeastern Anatolia, the southern coast of Crimea between Sevastopol and Feodosiya in Ukraine and the Black Sea coast between Anapa and Tuapse in Russia forms the Mediterranean Floristic Region, which belongs to the Tethyan Subkingdom of the Boreal Kingdom and is enclosed between the Circumboreal, Irano-Turanian, Saharo-Arabian and Macaronesian floristic regions.
The Mediterranean Region was first proposed by German botanist August Grisebach in the late 19th century.
The monotypic Drosophyllaceae, recently segregated from Droseraceae, is the only plant family endemic to the region. Among the endemic plant genera are:
The genera Aubrieta, Sesamoides, Cynara, Dracunculus, Arisarum and Biarum are nearly endemic. Among the endemic species prominent in the Mediterranean vegetation are the Aleppo pine, stone pine, Mediterranean cypress, bay laurel, Oriental sweetgum, holm oak, kermes oak, strawberry tree, Greek strawberry tree, mastic, terebinth, common myrtle, oleander, Acanthus mollis and Vitex agnus-castus. Moreover, many plant taxa are shared with one of the four neighboring floristic regions only. According to different versions of Armen Takhtajan's delineation, the Mediterranean Region is further subdivided into seven to nine floristic provinces: Southwestern Mediterranean (or Southern Moroccan and Southwestern Mediterranean), Ibero-Balearian (or Iberian and Balearian), Liguro-Tyrrhenian, Adriatic, East Mediterranean, South Mediterranean and Crimeo-Novorossiysk.[11]
The Mediterranean Basin is the largest of the world's five Mediterranean forests, woodlands, and scrub regions. It is home to a number of plant communities, which vary with rainfall, elevation, latitude, and soil.
The Mediterranean Basin is home to considerable biodiversity, including 22,500 endemic vascular plant species. Conservation International designates the region as a biodiversity hotspot, because of its rich biodiversity and its threatened status. The Mediterranean Basin has an area of 2,085,292 km2, of which only 98,009 km2 remains undisturbed.
Endangered mammals of the Mediterranean Basin include the Mediterranean monk seal, the Barbary macaque, and the Iberian lynx.
The WWF identifies 22 Mediterranean forests, woodlands, and scrub ecoregions in the Mediterranean Basin, most of which featuring sclerophyll plant species: