Macaronesia

Not to be confused with Micronesia.

Macaronesia

Macaronesia (Portuguese: Macaronésia) is a collection of four volcanic archipelagos in the North Atlantic Ocean, off the coasts of the continents of Europe and Africa. Each archipelago is made up of a number of Atlantic oceanic islands, which are formed by seamounts on the ocean floor and have peaks above the ocean's surface. Some of the Macaronesian islands belong Portugal, some belong to Spain, and the rest belong to Cape Verde. Politically, the islands belonging to Portugal and Spain are part of the European Union. Geologically, Macaronesia is part of the African Plate, including the Azores, which run along the edge of that plate at the point where it abuts the Eurasian and North American Plates.

Macaronesia comprises four archipelagos, of which three are European (the fourth is the the Cape Verde archipelago) According to the European Environment Agency, the three European archipelagos constitute a unique biogeographic realm, known as the Macaronesian Region.

Etymology

The name is derived from the Greek words for "islands of the fortunate" (μακάρων νησοι or μακάρων νήσοι, makárōn nisoi), a term used by Ancient Greek geographers for islands to the west of the Strait of Gibraltar. Macaronesia is occasionally misspelled "Macronesia" in false analogy with Micronesia, an unrelated group of archipelagos in the Pacific Ocean.

Archipelagos

Flags of the Macaronesian archipelagos

Macaronesia consists of four main archipelagos. From north to south, these are:

• the Azores, an Autonomous Region of Portugal
• Madeira (also including the Savage Islands), an Autonomous Region of Portugal
• the Canary Islands, an Autonomous Community of Spain
• Cape Verde, an independent West African country

Geography and geology

Macaronesian archipelagos were, and are still, created by volcanic activity. Layers of volcanic tephra formed by the 1957 eruption of Capelinhos volcano on the island of Faial in the Azores.

The islands of Macaronesia are volcanic in origin, and are thought to be the product of several geologic hotspots.

The climate of the Macaronesian islands ranges from maritime temperate, Mediterranean and subtropical in the Azores and Madeira, Mediterranean and subtropical in some Canary islands to arid in certain geologically older islands of the Canaries (Lanzarote, Fuerteventura), some islands of the Madeira Archipelago (Selvagens and Porto Santo) and Cape Verde (Sal, Boa Vista and Maio), and even tropical in the younger islands of both southern archipelagos (Santo Antão, Santiago and Fogo in Cape Verde). In some cases there are variations due to the rain shadow effect. The laurisilva forests of Macaronesia are a type of mountain cloud forest with relict species of a vegetation type which originally covered much of the Mediterranean Basin when the climate of that region was more humid. The species have evolved to adapt to the islands’ conditions and many are endemic.

The islands have a unique biogeography, and are home to several distinct plant and animal communities. The jumping spider genus Macaroeris is named after Macaronesia. None of the Macaronesian islands were part of a continent, so the native plants and animals reached the islands via long-distance dispersal. Laurel-leaved forests, called laurisilva, once covered most of the Azores, Madeira, and parts of the Canaries between 400 and 1200 m altitude (the eastern Canaries and Cape Verde being too dry). These forests resemble the ancient forests that covered the Mediterranean basin and northwestern Africa before the cooling and drying of the ice ages. Trees of the genera Apollonias, Clethra, Dracaena, Ocotea, Persea, and Picconia, which are found in the Macaronesian laurel forests, are also known from fossil evidence to have lived around the Mediterranean before the ice ages.

Conservation issues

Primeval laurisilva forest. Some remaining patches of this threatened original native nature in Macaronesia were protected by law in 2001, except in Cape Verde.

Felling of the forests for timber and firewood, clearing vegetation for grazing and agriculture, and the introduction of foreign plants and animals by humans have displaced much of the original native vegetation. The laurisilva habitat has been reduced to small disconnected pockets. As a result, many of the endemic biota of the islands are now seriously endangered or extinct. Alien predators – in particular domestic and feral cats – are currently one of the most serious threats to the endemic fauna. Despite the fact that cats prey mostly on introduced mammals, such as rodents and rabbits, this feeding sustains a bigger feline population (thought to be a hyperpredation process), and has a further impact on the endemic reptiles and birds.

In the European part of Macaronesia (Azores, Madeira and Canary Islands), conservation efforts include large areas protected by the Natura 2000 regulations of the European Union, since 2001. All in all, 5000 km² of land and sea are protected area in these three archipelagos.

See also

• Fortunate Isles
• List of islands in the Atlantic Ocean
• Laurel forest

External links

• European Union: Report on biodiversity in Macaronesia
• Review on cats' diet on Macaronesian islands