Palearctic realm

 ( Biogeography ) 

The Palearctic or Palaearctic is a biogeographic realm of the Earth, the largest of eight. Confined almost entirely to the Eastern Hemisphere, it stretches across Europe and Asia, north of the foothills of the Himalayas, and North Africa.

The realm consists of several Bioregion: the Mediterranean Basin; North Africa; North Arabia; Western Asia, Central Asia and East Asia. The Palaearctic realm also has numerous rivers and lakes, forming several freshwater ecoregions.

Both the eastern and westernmost extremes of the Paleartic span into the Western Hemisphere, including Cape Dezhnyov in Chukotka Autonomous Okrug to the east and Iceland to the west. The term was first used in the 19th century, and is still in use as the basis for Zoogeography classification.

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History In an 1858 paper for the Proceedings of the Linnean Society, British zoologist Philip Sclater first identified six terrestrial zoogeographic realms of the world: Palaearctic, Aethiopian/Afrotropic, Indian/, Australasian, Nearctic, and Neotropical. The six indicated general groupings of fauna, based on shared biogeography and large-scale geographic barriers to migration.

Alfred Wallace adopted Sclater's scheme for his book The Geographical Distribution of Animals, published in 1876. This is the same scheme that persists today, with relatively minor revisions, and the addition of two more realms: Oceanian realm and the Antarctic realm.

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Major ecological regions The Palearctic realm includes mostly boreal/subarctic-climate and temperate-climate ecoregions, which stretch from western Europe to the Bering Sea.

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Euro-Siberian region The boreal and temperate Euro-Siberian region is the Palearctic's largest biogeography region, which transitions from tundra in the northern reaches of Russia and Scandinavia to the vast taiga, the boreal coniferous forests which run across the continent. South of the taiga is a belt of temperate broadleaf and mixed forests and temperate coniferous forests. This vast Euro-Siberian region is characterized by many shared plant and animal species, and has many affinities with the temperate and boreal regions of the Nearctic realm of North America. Eurasia and North America were often connected by the Bering land bridge, and have very similar mammal and bird fauna, with many Eurasian species having moved into North America, and fewer North American species having moved into Eurasia. Many zoologists consider the Palearctic and Nearctic to be a single Holarctic realm. The Palearctic and Nearctic also share many plant species, which botanists call the Arcto-Tertiary Geoflora.

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Mediterranean Basin The lands bordering the Mediterranean Sea in southern Europe, north Africa, and western Asia are home to the Mediterranean Basin ecoregions, which together constitute the world's largest and most diverse mediterranean climate region of the world, with generally mild, rainy winters and hot, dry summers. The Mediterranean basin's mosaic of Mediterranean forests, woodlands, and scrub are home to 13,000 endemic species. The Mediterranean basin is also one of the world's most endangered biogeographic regions; only 4% of the region's original vegetation remains, and human activities, including overgrazing, deforestation, and conversion of lands for pasture, agriculture, and urbanization, have degraded much of the region. Formerly the region was mostly covered with forests and woodlands, but heavy human use has reduced much of the region to the sclerophyll shrublands known as chaparral, matorral, Maquis shrubland, or garrigue. Conservation International has designated the Mediterranean basin as one of the world's biodiversity hotspots.

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Sahara and Arabian deserts Horse latitudes, including the Atlantic coastal desert, Sahara Desert, and Arabian Desert, separates the Palearctic and Afrotropic ecoregions. This scheme includes these desert ecoregions in the palearctic realm; other biogeographers identify the realm boundary as the transition zone between the desert ecoregions and the Mediterranean basin ecoregions to the north, which places the deserts in the Afrotropic, while others place the boundary through the middle of the desert.

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Western and Central Asia The Caucasus mountains, which run between the Black Sea and the Caspian Sea, are a particularly rich mix of coniferous, broadleaf, and mixed forests, and include the temperate rain forests of the Euxine-Colchic deciduous forests ecoregion.

Central Asia and the Iranian plateau are home to dry steppe grasslands and desert basins, with montane forests, woodlands, and grasslands in the region's high mountains and plateaux. In southern Asia the boundary of the Palearctic is largely altitudinal. The middle altitude foothills of the Himalaya between about form the boundary between the Palearctic and Indomalaya ecoregions.

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East Asia China, Korea and Japan are more humid and temperate than adjacent Siberia and Central Asia, and are home to rich temperate coniferous, broadleaf, and mixed forests, which are now mostly limited to mountainous areas, as the densely populated lowlands and river basins have been converted to intensive agricultural and urban use. East Asia was not much affected by glaciation in the , and retained 96 percent of Pliocene tree genera, while Europe retained only 27 percent. In the subtropical region of southern China and southern edge of the Himalayas, the Palearctic temperate forests transition to the subtropical and tropical forests of Indomalaya, creating a rich and diverse mix of plant and animal species. The mountains of southwest China are also designated as a biodiversity hotspot. In Southeastern Asia, high form tongues of Palearctic flora and fauna in northern Indochina and southern China. Isolated small outposts () occur as far south as central Myanmar (on Nat Ma Taung, ), northernmost Vietnam (on Fan Si Pan, ) and the high mountains of Taiwan.

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Freshwater The realm contains several important freshwater ecoregions as well, including the heavily developed rivers of Europe, the rivers of Russia, which flow into the Arctic, Baltic Sea, Black Sea, and Caspian Sea seas, Siberia's Lake Baikal, the oldest and deepest lake on the planet, and Japan's ancient Lake Biwa.

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Flora and fauna One bird family, the (Prunellidae), is endemic to the Palearctic region. The Holarctic has four other endemic bird families: the divers or (Gaviidae), grouse (Tetraoninae), (Alcidae), and (Bombycillidae).

There are no endemic mammal orders in the region, but several families are endemic: Calomyscidae (mouse-like hamsters), Prolagidae, and Ailuridae (). Several mammal species originated in the Palearctic and spread to the Nearctic during the Ice Age, including the brown bear ( Ursus arctos, known in North America as the grizzly), red deer ( Cervus elaphus) in Europe and the closely related elk ( Cervus canadensis) in far eastern Siberia, American bison ( Bison bison), and reindeer ( Rangifer tarandus, known in North America as the caribou).

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Megafaunal extinctions Several large Palearctic animals became extinct from the end of the Pleistocene into historic times, including Irish elk ( Megaloceros giganteus), aurochs ( Bos primigenius), woolly rhinoceros ( Coelodonta antiquitatis), woolly mammoth ( Mammuthus primigenius), North African elephant ( Loxodonta africana pharaoensis), Chinese elephant ( Elephas maximus rubridens), cave bear ( Ursus spelaeus), Straight tusked elephant ( Palaeoloxodon antiquus) and European lion ( Panthera leo europaea).

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Palearctic terrestrial ecoregions , or major habitat types, as defined by Olson & Dinerstein, et al. (2001).Olson, D. M., Dinerstein, E., Wikramanayake, E. D., Burgess, N. D., Powell, G. V. N., Underwood, E. C., D'Amico, J. A., Itoua, I., Strand, H. E., Morrison, J. C., Loucks, C. J., Allnutt, T. F., Ricketts, T. H., Kura, Y., Lamoreux, J. F., Wettengel, W. W., Hedao, P., Kassem, K. R. (2001). Terrestrial ecoregions of the world: a new map of life on Earth. Bioscience 51(11):933–938, [1] .

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Apennine deciduous montane forests	Italy
Atlantic mixed forests	Belgium, Denmark, France, Germany, Netherlands
Azores temperate mixed forests	Portugal
Balkan mixed forests	Bosnia and Herzegovina, Bulgaria, Greece, Kosovo, North Macedonia, Romania, Serbia, Turkey
Baltic mixed forests	Denmark, Germany, Poland, Sweden
Cantabrian mixed forests	France, Portugal, Spain
Caspian Hyrcanian mixed forests	Azerbaijan, Iran
Caucasus mixed forests	Armenia, Azerbaijan, Georgia, Iran, Russia, Turkey
Celtic broadleaf forests	Ireland, United Kingdom
Central Anatolian deciduous forests	Turkey
Central China loess plateau mixed forests	China
Central European mixed forests	Austria, Belarus, Czech Republic, Germany, Lithuania, Moldova, Poland, Romania, Russia, Ukraine
Central Korean deciduous forests	North Korea, South Korea
Changbai Mountains mixed forests	China, North Korea
Changjiang Plain evergreen forests	China
Crimean Submediterranean forest complex	Russia, Ukraine
Daba Mountains evergreen forests	China
Dinaric Mountains mixed forests	Albania, Bosnia and Herzegovina, Croatia, Italy, Kosovo, Montenegro, Serbia, Slovenia
East European forest steppe	Bulgaria, Moldova, Romania, Russia, Ukraine
Eastern Anatolian deciduous forests	Turkey
English Lowlands beech forests	United Kingdom
Euxine–Colchic deciduous forests	Bulgaria, Georgia, Turkey
Hokkaido deciduous forests	Japan
Huang He Plain mixed forests	China
Madeira evergreen forests	Portugal
Manchurian mixed forests	China, North Korea, Russia, South Korea
Nihonkai evergreen forests	Japan
Nihonkai montane deciduous forests	Japan
North Atlantic moist mixed forests	Ireland, United Kingdom (Northern Ireland, Scotland), Denmark (Faroe Islands)
Northeast China Plain deciduous forests	China
Pannonian mixed forests	Austria, Bosnia and Herzegovina, Croatia, Czech Republic, Hungary, Romania, Serbia, Slovakia, Slovenia, Ukraine
Po Basin mixed forests	Italy Switzerland
Pyrenees conifer and mixed forests	Andorra, France, Spain
Qin Ling Mountains deciduous forests	China
Rodope montane mixed forests	Bulgaria, Greece, North Macedonia, Serbia
Sarmatic mixed forests	Belarus, Denmark, Estonia, Finland, Latvia, Lithuania, Norway, Russia, Sweden
Sichuan Basin evergreen broadleaf forests	China
South Sakhalin–Kurile mixed forests	Russia
Southern Korea evergreen forests	South Korea
Taiheiyo evergreen forests	Japan
Taiheiyo montane deciduous forests	Japan
Tarim Basin deciduous forests and steppe	China
Ussuri broadleaf and mixed forests	Russia
West Siberian broadleaf and mixed forests	Russia
Western European broadleaf forests	Austria, Belgium, Czech Republic, France, Germany, Luxembourg. Netherlands, Poland, Switzerland
Zagros Mountains forest steppe	Iran, Iraq, Turkey

Afghan Mountains semi-desert	Afghanistan
Alashan Plateau semi-desert	China, Mongolia
Arabian Desert	Egypt, Israel, Iraq, Jordan, Kuwait, Palestine, Saudi Arabia, Yemen
Atlantic coastal desert	Mauritania, Western Sahara
Azerbaijan shrub desert and steppe	Azerbaijan, Georgia, Iran
Badghyz and Karabil semi-desert	Afghanistan, Iran, Tajikistan, Turkmenistan, Uzbekistan
Baluchistan xeric woodlands	Afghanistan, Pakistan
Caspian lowland desert	Iran, Kazakhstan, Russia, Turkmenistan
Central Afghan Mountains xeric woodlands	Afghanistan
Central Asian northern desert	Kazakhstan, Uzbekistan
Central Asian riparian woodlands	Kazakhstan, Turkmenistan, Uzbekistan
Central Asian southern desert	Kazakhstan, Turkmenistan, Uzbekistan
Central Persian desert basins	Afghanistan, Iran
Eastern Gobi desert steppe	China, Mongolia
Gobi Lakes Valley desert steppe	Mongolia
Great Lakes Basin desert steppe	Mongolia, Russia
Dzungaria	China, Mongolia
Kazakh semi-desert	Kazakhstan
Kopet Dag semi-desert	Iran, Turkmenistan
Mesopotamian shrub desert	Iraq, Iran, Israel, Jordan, Syria
North Saharan steppe and woodlands	Algeria, Egypt, Libya, Mauritania, Morocco, Tunisia, Western Sahara
Paropamisus xeric woodlands	Afghanistan
Persian Gulf desert and semi-desert	Bahrain, Kuwait, Oman, Qatar, Saudi Arabia, United Arab Emirates
Qaidam Basin semi-desert	China
Red Sea coastal desert	Egypt, Sudan
Red Sea Nubo–Sindian tropical desert and semi-desert	Egypt, Jordan, Oman, Saudi Arabia, Yemen
Registan–North Pakistan sandy desert	Afghanistan, Iran, Pakistan
Sahara desert	Algeria, Chad, Egypt, Libya, Mali, Niger, Sudan, Western Sahara
South Iran Nubo–Sindian desert and semi-desert	Iran, Iraq, Pakistan
South Saharan steppe and woodlands	Algeria, Chad, Mali, Mauritania, Niger, Sudan
Taklimakan desert	China
Tibesti–Jebel Uweinat montane xeric woodlands	Chad, Egypt, Libya, Sudan
West Saharan montane xeric woodlands	Algeria, Mali, Mauritania, Niger

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General references

• Amorosi, T. "Contributions to the zooarchaeology of Iceland: some preliminary notes" in The Anthropology of Iceland (eds. E.P. Durrenberger & G. Pálsson). Iowa City: University of Iowa Press, pp. 203–227, 1989.
• Buckland, P.C., et al. "Holt in Eyjafjasveit, Iceland: a paleoecological study of the impact of Landnám" in Acta Archaeologica 61: pp. 252–271. 1991.
• http://www.Merriam-Webster.com
• http://www.Canadianbiodiversity.mcgill.ca
• http://www.bbc.co.uk/nature/ecozones/Palearctic_ecozone
• Edmund Burke III, "The Transformation of the middle Eastern Environment, 1500 B.C.E.–2000 C.E." in The Environment and World History, ed. Edmund Burke III and Kenneth Pomeranz. Berkeley: University of California Press. 2009, 82–84.

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External links

• Avionary 1500 Bird species of the Western and Central Palaearctic in 46 languages
• Map of the ecozones

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