# Palearctic realm

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 all of Eurasia north of the foothills of the Himalayas, and North Africa.
The realm consists of several bioregions, variously spanning the Euro-Siberian region; the Mediterranean Basin; North Africa; North Arabia; and Western, Central 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 zoogeographic classification.

## 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/Indomalayan, 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: Oceania and the Antarctic realm.

## Major ecological regions

The Palearctic realm includes mostly boreal/subarctic-climate and temperate-climate ecoregions, which run across Eurasia from western Europe to the Bering Sea.

### Euro-Siberian region

The boreal and temperate Euro-Siberian region is the Palearctic's largest biogeographic 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 are 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.

### 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, or garrigue. Conservation International has designated the Mediterranean basin as one of the world's biodiversity hotspots.

### Sahara and Arabian deserts

A great belt of deserts, 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.

### 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 2,000–2,500 m (6,600–8,200 ft) form the boundary between the Palearctic and Indomalaya ecoregions.

### 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 ice ages, 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 mountain ranges form tongues of Palearctic flora and fauna in northern Indochina and southern China. Isolated small outposts (sky islands) occur as far south as central Myanmar (on Nat Ma Taung, 3,050 m; 10,010 ft), northernmost Vietnam (on Fan Si Pan, 3,140 m; 10,300 ft) and the high mountains of Taiwan.

### 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, Black, and Caspian seas, Siberia's Lake Baikal, the oldest and deepest lake on the planet, and Japan's ancient Lake Biwa.

## Flora and fauna

One bird family, the accentors (Prunellidae), is endemic to the Palearctic region. The Holarctic has four other endemic bird families: the divers or loons (Gaviidae), grouse (Tetraoninae), auks (Alcidae), and waxwings (Bombycillidae).
There are no endemic mammal orders in the region, but several families are endemic: Calomyscidae (mouse-like hamsters), Prolagidae, and Ailuridae (red pandas). 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).

### 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).

## Palearctic terrestrial ecoregions

Palearctic tropical and subtropical moist broadleaf forests ecoregionsvte :
| Guizhou Plateau broadleaf and mixed forests | China |
| Yunnan Plateau subtropical evergreen forests | China |
Palearctic temperate broadleaf and mixed forests :
| 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 |
vtePalearctic temperate coniferous forests ecoregions :
| Alps conifer and mixed forests | Austria, France, Germany, Italy, Slovenia, Switzerland |
| Altai montane forest and forest steppe | China, Kazakhstan, Mongolia, Russia |
| Caledon conifer forests | United Kingdom |
| Carpathian montane conifer forests | Czech Republic, Poland, Romania, Slovakia, Ukraine |
| Da Hinggan–Dzhagdy Mountains conifer forests | China, Russia |
| East Afghan montane conifer forests | Afghanistan, Pakistan |
| Elburz Range forest steppe | Iran |
| Helanshan montane conifer forests | China |
| Hengduan Mountains subalpine conifer forests | China |
| Hokkaido montane conifer forests | Japan |
| Honshū alpine conifer forests | Japan |
| Khangai Mountains conifer forests | Mongolia |
| Mediterranean conifer and mixed forests | Algeria, Morocco, Spain, Tunisia |
| Northeastern Himalayan subalpine conifer forests | China, India, Bhutan |
| Northern Anatolian conifer and deciduous forests | Turkey |
| Nujiang Langcang Gorge alpine conifer and mixed forests | China |
| Qilian Mountains conifer forests | China |
| Qionglai–Minshan conifer forests | China |
| Sayan montane conifer forests | Mongolia, Russia |
| Scandinavian coastal conifer forests | Norway |
| Tian Shan montane conifer forests | China, Kazakhstan, Kyrgyzstan |
Palearctic boreal forests/taiga ecoregionsvte :
| East Siberian taiga | Russia |
| Iceland boreal birch forests and alpine tundra | Iceland |
| Kamchatka–Kurile meadows and sparse forests | Russia |
| Kamchatka–Kurile taiga | Russia |
| Northeast Siberian taiga | Russia |
| Okhotsk–Manchurian taiga | Russia |
| Sakhalin Island taiga | Russia |
| Scandinavian and Russian taiga | Finland, Norway, Russia, Sweden |
| Trans-Baikal conifer forests | Mongolia, Russia |
| Urals montane tundra and taiga | Russia |
| West Siberian taiga | Russia |
Palearctic temperate grasslands, savannas, and shrublands ecoregionsvte :
| Alai–Western Tian Shan steppe | Kazakhstan, Tajikistan, Uzbekistan |
| Altai steppe and semi-desert | Kazakhstan |
| Central Anatolian steppe | Turkey |
| Daurian forest steppe | China, Mongolia, Russia |
| Eastern Anatolian montane steppe | Armenia, Azerbaijan, Georgia, Iran, Turkey |
| Emin Valley steppe | China, Kazakhstan |
| Faroe Islands boreal grasslands | Faroe Islands, Denmark |
| Gissaro–Alai open woodlands | Kyrgyzstan, Tajikistan, Uzbekistan |
| Kazakh forest steppe | Kazakhstan, Russia |
| Kazakh steppe | Kazakhstan, Russia |
| Kazakh Uplands | Kazakhstan |
| Mongolian–Manchurian grassland | China, Mongolia, Russia |
| Pontic steppe | Kazakhstan, Moldova, Romania, Russia, Ukraine, Bulgaria |
| Sayan Intermontane steppe | Russia |
| Selenge–Orkhon forest steppe | Mongolia, Russia |
| South Siberian forest steppe | Russia |
| Syrian xeric grasslands and shrublands | Iraq, Jordan, Syria |
| Tian Shan foothill arid steppe | China, Kazakhstan, Kyrgyzstan |
Palearctic flooded grasslands and savannas ecoregionsvte :
| Amur meadow steppe | China, Russia |
| Bohai Sea saline meadow | China |
| Nenjiang River grassland | China |
| Nile Delta flooded savanna | Egypt |
| Saharan halophytics | Algeria, Egypt, Mauritania, Tunisia, Western Sahara |
| Tigris–Euphrates alluvial salt marsh | Iraq, Iran |
| Ussuri-Wusuli meadow and forest meadow | China, Russia |
| Yellow Sea saline meadow | China |
Palearctic montane grasslands and shrublands ecoregionsvte :
| Altai alpine meadow and tundra | China, Kazakhstan, Mongolia, Russia |
| Central Tibetan Plateau alpine steppe | China |
| Eastern Himalayan alpine shrub and meadows | Bhutan, Myanmar, China, India, Nepal |
| Ghorat–Hazarajat alpine meadow | Afghanistan |
| Hindu Kush alpine meadow | Afghanistan |
| Karakoram–West Tibetan Plateau alpine steppe | Afghanistan, China, India, Pakistan |
| Khangai Mountains alpine meadow | Mongolia |
| Kopet Dag woodlands and forest steppe | Iran, Turkmenistan |
| Kuh Rud and Eastern Iran montane woodlands | Iran |
| Mediterranean High Atlas juniper steppe | Morocco |
| North Tibetan Plateau–Kunlun Mountains alpine desert | China |
| Northwestern Himalayan alpine shrub and meadows | China, India, Pakistan |
| Ordos Plateau steppe | China |
| Pamir alpine desert and tundra | Afghanistan, China, Kyrgyzstan, Tajikistan |
| Qilian Mountains subalpine meadows | China |
| Sayan alpine meadows and tundra | Mongolia, Russia |
| Southeast Tibet shrub and meadows | China |
| Sulaiman Range alpine meadows | Afghanistan, Pakistan |
| Tian Shan montane steppe and meadows | China, Kazakhstan, Kyrgyzstan |
| Tibetan Plateau alpine shrublands and meadows | China |
| Western Himalayan alpine shrub and meadows | India, Nepal |
| Yarlung Zambo arid steppe | China |
Palearctic tundra ecoregionsvte :
| Arctic desert | Russia, Svalbard (Norway) |
| Bering tundra | Russia |
| Cherskii–Kolyma mountain tundra | Russia |
| Chukchi Peninsula tundra | Russia |
| Kamchatka Mountain tundra and forest tundra | Russia |
| Kola Peninsula tundra | Norway, Russia |
| Northeast Siberian coastal tundra | Russia |
| Northwest Russian–Novaya Zemlya tundra | Russia |
| New Siberian Islands arctic desert | Russia |
| Scandinavian montane birch forest and grasslands | Finland, Norway, Sweden |
| Taimyr–Central Siberian tundra | Russia |
| Trans-Baikal Bald Mountain tundra | Russia |
| Wrangel Island arctic desert | Russia |
| Yamalagydanskaja tundra | Russia |
Palearctic Mediterranean forests, woodlands, and scrub ecoregionsvte :
| Aegean and Western Turkey sclerophyllous and mixed forests | Greece, North Macedonia, Turkey |
| Anatolian conifer and deciduous mixed forests | Turkey |
| Canary Islands dry woodlands and forests | Spain |
| Corsican montane broadleaf and mixed forests | France |
| Crete Mediterranean forests | Greece |
| Cyprus Mediterranean forests | Cyprus |
| Eastern Mediterranean conifer–sclerophyllous–broadleaf forests | Israel, Jordan, Lebanon, Syria, Turkey |
| Iberian conifer forests | Spain |
| Iberian sclerophyllous and semi-deciduous forests | Portugal, Spain |
| Illyrian deciduous forests | Albania, Bosnia and Herzegovina, Croatia, Greece, Italy, Slovenia |
| Italian sclerophyllous and semi-deciduous forests | France, Italy |
| Mediterranean acacia-argania dry woodlands and succulent thickets | Morocco, Canary Islands (Spain) |
| Mediterranean dry woodlands and steppe | Algeria, Egypt, Libya, Morocco, Tunisia |
| Mediterranean woodlands and forests | Algeria, Libya, Morocco, Tunisia |
| Northeastern Spain and Southern France Mediterranean forests | France, Monaco, Spain |
| Northwest Iberian montane forests | Portugal, Spain |
| Pindus Mountains mixed forests | Albania, Greece, North Macedonia |
| South Apennine mixed montane forests | Italy |
| Southeastern Iberian shrubs and woodlands | Spain |
| Southern Anatolian montane conifer and deciduous forests | Israel, Jordan, Lebanon, Syria, Turkey |
| Southwest Iberian Mediterranean sclerophyllous and mixed forests | Portugal, Spain |
| Tyrrhenian–Adriatic sclerophyllous and mixed forests | Croatia, France, Italy, Malta |
Palearctic deserts and xeric shrublands :
| 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 |
| Junggar Basin semi-desert | 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 |