The Palearctic or Palaearctic is the largest of the eight

biogeographic realm A biogeographic realm or ecozone is the broadest biogeographic division of Earth's land surface, based on distributional patterns of terrestrial organisms. They are subdivided into bioregions, which are further subdivided into ecoregions. De ...

s of the Earth. It stretches across all of

Eurasia Eurasia (, ) is the largest continental area on Earth, comprising all of Europe and Asia. Primarily in the Northern and Eastern Hemispheres, it spans from the British Isles and the Iberian Peninsula in the west to the Japanese archipelago ...

north of the foothills of the

Himalayas The Himalayas, or Himalaya (; ; ), is a mountain range in Asia, separating the plains of the Indian subcontinent from the Tibetan Plateau. The range has some of the planet's highest peaks, including the very highest, Mount Everest. Over 10 ...

, and

North Africa North Africa, or Northern Africa is a region encompassing the northern portion of the African continent. There is no singularly accepted scope for the region, and it is sometimes defined as stretching from the Atlantic shores of Mauritania in ...

. The realm consists of several

bioregion A bioregion is an ecologically and geographically defined area that is smaller than a biogeographic realm, but larger than an ecoregion or an ecosystem, in the World Wide Fund for Nature classification scheme. There is also an attempt to use the ...

s: the Euro-Siberian region; the Mediterranean Basin; the Sahara and Arabian Deserts; and

Western Western may refer to: Places *Western, Nebraska, a village in the US *Western, New York, a town in the US *Western Creek, Tasmania, a locality in Australia *Western Junction, Tasmania, a locality in Australia *Western world, countries that id ...

, Central and

East Asia East Asia is the eastern region of Asia, which is defined in both Geography, geographical and culture, ethno-cultural terms. The modern State (polity), states of East Asia include China, Japan, Mongolia, North Korea, South Korea, and Taiwan. ...

. The Palaearctic realm also has numerous rivers and lakes, forming several freshwater ecoregions. The term 'Palearctic' 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 The Linnean Society of London is a learned society dedicated to the study and dissemination of information concerning natural history, evolution, and taxonomy. It possesses several important biological specimen, manuscript and literature colle ...

'', British zoologist

Philip Sclater Philip Lutley Sclater (4 November 1829 – 27 June 1913) was an England, English lawyer and zoologist. In zoology, he was an expert ornithologist, and identified the main zoogeographic regions of the world. He was Secretary of the Zoological ...

first identified six terrestrial zoogeographic realms of the world: Palaearctic, Aethiopian/

Afrotropic The Afrotropical realm is one of Earth's eight biogeographic realms. It includes Africa south of the Sahara Desert, the majority of the Arabian Peninsula, the island of Madagascar, southern Iran and extreme southwestern Pakistan, and the island ...

Indian Indian or Indians may refer to: Peoples South Asia * Indian people, people of Indian nationality, or people who have an Indian ancestor ** Non-resident Indian, a citizen of India who has temporarily emigrated to another country * South Asia ...

Indomalaya The Indomalayan realm is one of the eight biogeographic realms. It extends across most of South and Southeast Asia and into the southern parts of East Asia. Also called the Oriental realm by biogeographers, Indomalaya spreads all over the Indi ...

n, Australasian,

Nearctic The Nearctic realm is one of the eight biogeographic realms constituting the Earth's land surface. The Nearctic realm covers most of North America, including Greenland, Central Florida, and the highlands of Mexico. The parts of North America ...

, and

Neotropical The Neotropical realm is one of the eight biogeographic realms constituting Earth's land surface. Physically, it includes the tropical terrestrial ecoregions of the Americas and the entire South American temperate zone. Definition In bioge ...

. The six indicated general groupings of fauna, based on shared biogeography and large-scale geographic barriers to migration. Wallace03

Alfred Wallace Alfred Russel Wallace (8 January 1823 – 7 November 1913) was a British naturalist, explorer, geographer, anthropologist, biologist and illustrator. He is best known for independently conceiving the theory of evolution through natural se ...

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 Oceania (, , ) is a geographical region that includes Australasia, Melanesia, Micronesia, and Polynesia. Spanning the Eastern and Western hemispheres, Oceania is estimated to have a land area of and a population of around 44.5 million ...

and the

Antarctic realm The Antarctic realm is one of eight terrestrial biogeographic realms. The ecosystem includes Antarctica and several island groups in the southern Atlantic and Indian oceans. The continent of Antarctica is so cold that it has supported only 2 ...

Major ecological regions

The Palearctic realm includes mostly boreal/subarctic-climate and temperate-climate ecoregions, which run across

from western Europe to the Bering Sea.

Euro-Siberian region

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

biogeographic Biogeography is the study of the distribution of species and ecosystems in geographic space and through geological time. Organisms and biological communities often vary in a regular fashion along geographic gradients of latitude, elevation, ...

region, which transitions from

tundra In physical geography, tundra () is a type of biome where tree growth is hindered by frigid temperatures and short growing seasons. The term ''tundra'' comes through Russian (') from the Kildin Sámi word (') meaning "uplands", "treeless mou ...

in the northern reaches of

Russia Russia (, , ), or the Russian Federation, is a transcontinental country spanning Eastern Europe and Northern Asia. It is the largest country in the world, with its internationally recognised territory covering , and encompassing one-eig ...

and

Scandinavia Scandinavia; Sámi languages: /. ( ) is a subregion in Northern Europe, with strong historical, cultural, and linguistic ties between its constituent peoples. In English usage, ''Scandinavia'' most commonly refers to Denmark, Norway, and Swe ...

to the vast

taiga Taiga (; rus, тайга́, p=tɐjˈɡa; relates to Mongolic and Turkic languages), generally referred to in North America as a boreal forest or snow forest, is a biome characterized by coniferous forests consisting mostly of pines, spruc ...

, the boreal coniferous forests which run across the continent. South of the taiga are a belt of

temperate broadleaf and mixed forests Temperate broadleaf and mixed forest is a temperate climate terrestrial habitat type defined by the World Wide Fund for Nature, with broadleaf tree ecoregions, and with conifer and broadleaf tree mixed coniferous forest ecoregions. These f ...

and

temperate coniferous forest Temperate coniferous forest is a terrestrial biome defined by the World Wide Fund for Nature. Temperate coniferous forests are found predominantly in areas with warm summers and cool winters, and vary in their kinds of plant life. In some, needle ...

s. 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 Beringia is defined today as the land and maritime area bounded on the west by the Lena River in Russia; on the east by the Mackenzie River in Canada; on the north by 72 degrees north latitude in the Chukchi Sea; and on the south by the tip of ...

, 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 Holarctic realm is a biogeographic realm that comprises the majority of habitats found throughout the continents in the Northern Hemisphere. It corresponds to the floristic Boreal Kingdom. It includes both the Nearctic zoogeographical regio ...

. The Palearctic and Nearctic also share many plant species, which botanists call the

Arcto-Tertiary Geoflora The Arcto-Tertiary Geoflora is a hypothesized floral assemblage that once covered the Northern Hemisphere, from roughly the late Mesozoic to mid Cenozoic Eras. Origins First proposed by the paleobotanists J.S. Gardner and C. Ettinghausen in 18 ...

Mediterranean Basin

The lands bordering the

Mediterranean Sea The Mediterranean Sea is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean Basin and almost completely enclosed by land: on the north by Western and Southern Europe and Anatolia, on the south by North Africa, and on the ...

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 A Mediterranean climate (also called a dry summer temperate climate ''Cs'') is a temperate climate sub-type, generally characterized by warm, dry summers and mild, fairly wet winters; these weather conditions are typically experienced in the ...

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 Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found else ...

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 Overgrazing occurs when plants are exposed to intensive grazing for extended periods of time, or without sufficient recovery periods. It can be caused by either livestock in poorly managed agricultural applications, game reserves, or nature res ...

deforestation Deforestation or forest clearance is the removal of a forest or stand of trees from land that is then converted to non-forest use. Deforestation can involve conversion of forest land to farms, ranches, or urban use. The most concentrated ...

, 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 Sclerophyll is a type of vegetation that is adapted to long periods of dryness and heat. The plants feature hard leaves, short internodes (the distance between leaves along the stem) and leaf orientation which is parallel or oblique to direct ...

shrublands known as chaparral, matorral, maquis, or

garrigue Garrigue or garigue ( ), also known as phrygana ( el, φρύγανα , n. pl.), is a type of low scrubland ecoregion and plant community in the Mediterranean forests, woodlands, and scrub biome. It is found on limestone soils in southern ...

. Conservation International has designated the Mediterranean basin as one of the world's

biodiversity hotspot A biodiversity hotspot is a biogeographic region with significant levels of biodiversity that is threatened by human habitation. Norman Myers wrote about the concept in two articles in ''The Environmentalist'' in 1988 and 1990, after which the c ...

Sahara and Arabian deserts

A great belt of deserts, including the

Atlantic coastal desert The Atlantic coastal desert is the westernmost ecoregion in the Sahara Desert of North Africa. It occupies a narrow strip along the Atlantic coast, where the more frequent fog and haze generated offshore by the cool Canary Current provides suf ...

, Sahara desert, and Arabian desert, separates the Palearctic and

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 The Caucasus () or Caucasia (), is a region between the Black Sea and the Caspian Sea, mainly comprising Armenia, Azerbaijan, Georgia (country), Georgia, and parts of Southern Russia. The Caucasus Mountains, including the Greater Caucasus range ...

mountains, which run between the

Black Sea The Black Sea is a marginal mediterranean sea of the Atlantic Ocean lying between Europe and Asia, east of the Balkans, south of the East European Plain, west of the Caucasus, and north of Anatolia. It is bounded by Bulgaria, Georgia, Rom ...

and the

Caspian Sea The Caspian Sea is the world's largest inland body of water, often described as the world's largest lake or a full-fledged sea. An endorheic basin, it lies between Europe and Asia; east of the Caucasus, west of the broad steppe of Central Asia ...

, are a particularly rich mix of coniferous, broadleaf, and mixed forests, and include the

temperate rain forest Temperate rainforests are coniferous or broadleaf forests that occur in the temperate zone and receive heavy rain. Temperate rain forests occur in oceanic moist regions around the world: the Pacific temperate rain forests of North American P ...

s of the Euxine-Colchic deciduous forests ecoregion.

Central Asia Central Asia, also known as Middle Asia, is a subregion, region of Asia that stretches from the Caspian Sea in the west to western China and Mongolia in the east, and from Afghanistan and Iran in the south to Russia in the north. It includes t ...

and the

Iranian plateau The Iranian plateau or Persian plateau is a geological feature in Western Asia, Central Asia, and South Asia. It comprises part of the Eurasian Plate and is wedged between the Arabian Plate and the Indian Plate; situated between the Zagros ...

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 The Himalayas, or Himalaya (; ; ), is a mountain range in Asia, separating the plains of the Indian subcontinent from the Tibetan Plateau. The range has some of the planet's highest peaks, including the very highest, Mount Everest. Over 100 ...

between about 2000–2500 m form the boundary between the Palearctic and

ecoregions.

East Asia

China,

Korea Korea ( ko, 한국, or , ) is a peninsular region in East Asia. Since 1945, it has been divided at or near the 38th parallel, with North Korea (Democratic People's Republic of Korea) comprising its northern half and South Korea (Republic o ...

and Japan are more humid and temperate than adjacent

Siberia Siberia ( ; rus, Сибирь, r=Sibir', p=sʲɪˈbʲirʲ, a=Ru-Сибирь.ogg) is an extensive region, geographical region, constituting all of North Asia, from the Ural Mountains in the west to the Pacific Ocean in the east. It has been a ...

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 age An ice age is a long period of reduction in the temperature of Earth's surface and atmosphere, resulting in the presence or expansion of continental and polar ice sheets and alpine glaciers. Earth's climate alternates between ice ages and gre ...

s, and retained 96 percent of

Pliocene The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58Indomalaya The Indomalayan realm is one of the eight biogeographic realms. It extends across most of South and Southeast Asia and into the southern parts of East Asia. Also called the Oriental realm by biogeographers, Indomalaya spreads all over the Indi ...

, creating a rich and diverse mix of plant and animal species. The mountains of southwest China are also designated as a

. In Southeastern Asia, high

mountain range A mountain range or hill range is a series of mountains or hills arranged in a line and connected by high ground. A mountain system or mountain belt is a group of mountain ranges with similarity in form, structure, and alignment that have arise ...

s form tongues of Palearctic flora and fauna in northern

Indochina Mainland Southeast Asia, also known as the Indochinese Peninsula or Indochina, is the continental portion of Southeast Asia. It lies east of the Indian subcontinent and south of Mainland China and is bordered by the Indian Ocean to the west an ...

and southern China. Isolated small outposts (

sky island Sky islands are isolated mountains surrounded by radically different lowland environments. The term originally referred to those found on the Mexican Plateau, and has extended to similarly isolated high-elevation forests. The isolation has s ...

s) occur as far south as central Myanmar (on

Nat Ma Taung Nat Ma Taung ( my, နတ်မတောင်; Khaw-nu-soum or Khonuamthung in Chin), also known as Mount Victoria, is the highest mountain in the Chin State of western Burma. Geography With a height of above sea level and a prominence of , ...

, 3050 m), northernmost

Vietnam Vietnam or Viet Nam ( vi, Việt Nam, ), officially the Socialist Republic of Vietnam,., group="n" is a country in Southeast Asia, at the eastern edge of mainland Southeast Asia, with an area of and population of 96 million, making i ...

(on Fan Si Pan, 3140 m) and the high mountains of

Taiwan Taiwan, officially the Republic of China (ROC), is a country in East Asia, at the junction of the East and South China Seas in the northwestern Pacific Ocean, with the People's Republic of China (PRC) to the northwest, Japan to the nort ...

Freshwater

The realm contains several important

freshwater ecoregion An ecoregion (ecological region) or ecozone (ecological zone) is an ecologically and geographically defined area that is smaller than a bioregion, which in turn is smaller than a biogeographic realm. Ecoregions cover relatively large areas of l ...

s as well, including the heavily developed rivers of Europe, the

rivers of Russia Russia can be divided into a European and an Asian part. The dividing line is generally considered to be the Ural Mountains. The European part is drained into the Arctic Ocean, Baltic Sea, Black Sea, and Caspian Sea. The Asian part is drained int ...

, which flow into the

Arctic The Arctic ( or ) is a polar region located at the northernmost part of Earth. The Arctic consists of the Arctic Ocean, adjacent seas, and parts of Canada (Yukon, Northwest Territories, Nunavut), Danish Realm (Greenland), Finland, Iceland, N ...

Baltic Baltic may refer to: Peoples and languages * Baltic languages, a subfamily of Indo-European languages, including Lithuanian, Latvian and extinct Old Prussian *Balts (or Baltic peoples), ethnic groups speaking the Baltic languages and/or originati ...

Black Black is a color which results from the absence or complete absorption of visible light. It is an achromatic color, without hue, like white and grey. It is often used symbolically or figuratively to represent darkness. Black and white ...

, and

Caspian sea The Caspian Sea is the world's largest inland body of water, often described as the world's largest lake or a full-fledged sea. An endorheic basin, it lies between Europe and Asia; east of the Caucasus, west of the broad steppe of Central Asia ...

's Lake Baikal, the oldest and deepest lake on the planet, and Japan's ancient

Lake Biwa is the largest freshwater lake in Japan, located entirely within Shiga Prefecture (west-central Honshu), northeast of the former capital city of Kyoto. Lake Biwa is an ancient lake, over 4 million years old. It is estimated to be the 13th ol ...

Flora and fauna

One bird family, the

accentor The accentors are a genus of birds in the family Prunellidae, which is endemic to the Old World. This small group of closely related passerines are all in the genus ''Prunella''. All but the dunnock and the Japanese accentor are inhabitants of th ...

s (Prunellidae), is endemic to the Palearctic region. The

Holarctic The Holarctic realm is a biogeographic realm that comprises the majority of habitats found throughout the continents in the Northern Hemisphere. It corresponds to the floristic Boreal Kingdom. It includes both the Nearctic zoogeographical reg ...

has four other endemic bird families: the divers or loons (Gaviidae),

grouse Grouse are a group of birds from the order Galliformes, in the family Phasianidae. Grouse are presently assigned to the tribe Tetraonini (formerly the subfamily Tetraoninae and the family Tetraonidae), a classification supported by mitochondria ...

(Tetraoninae),

auk An auk or alcid is a bird of the family Alcidae in the order Charadriiformes. The alcid family includes the murres, guillemots, auklets, puffins, and murrelets. The word "auk" is derived from Icelandic ''álka'', from Old Norse ''alka'' (a ...

s (Alcidae), and

waxwing The waxwings are three species of passerine birds classified in the genus ''Bombycilla''. They are pinkish-brown and pale grey with distinctive smooth plumage in which many body feathers are not individually visible, a black and white eyestripe, ...

s (Bombycillidae). There are no endemic mammal orders in the region, but several families are endemic: Calomyscidae (

mouse-like hamster 200px, right 200px, Mouse-like hamster using its tail for balance while standing on a branch (a feat difficult for hamsters) Mouse-like hamsters are a group of small rodents found in Syria, Azerbaijan, Iran, Turkmenistan, Afghanistan, and Pakis ...

s),

Prolagidae ''Prolagus'' is an extinct genus of pika within the order Lagomorpha. Over 20 species of ''Prolagus'' have been named, beginning in the Early Miocene in Europe 20 million years ago, where it ranged widely for most of the epoch; by the end of the ...

, and Ailuridae (

red panda The red panda (''Ailurus fulgens''), also known as the lesser panda, is a small mammal native to the eastern Himalayas and southwestern China. It has dense reddish-brown fur with a black belly and legs, white-lined ears, a mostly white muzzle ...

s). Several mammal species originated in the Palearctic and spread to the Nearctic during the Ice Age, including the

brown bear The brown bear (''Ursus arctos'') is a large bear species found across Eurasia and North America. In North America, the populations of brown bears are called grizzly bears, while the subspecies that inhabits the Kodiak Islands of Alaska is ...

(''Ursus arctos'', known in North America as the grizzly),

red deer The red deer (''Cervus elaphus'') is one of the largest deer species. A male red deer is called a stag or hart, and a female is called a hind. The red deer inhabits most of Europe, the Caucasus Mountains region, Anatolia, Iran, and parts of we ...

(''Cervus elaphus'') in Europe and the closely related elk (''Cervus canadensis'') in far eastern Siberia,

American bison The American bison (''Bison bison'') is a species of bison native to North America. Sometimes colloquially referred to as American buffalo or simply Bubalina, buffalo (a different clade of bovine), it is one of two extant species of bison, alongs ...

(''Bison bison''), and

reindeer Reindeer (in North American English, known as caribou if wild and ''reindeer'' if domesticated) are deer in the genus ''Rangifer''. For the last few decades, reindeer were assigned to one species, ''Rangifer tarandus'', with about 10 sub ...

(''Rangifer tarandus'', known in North America as the caribou).

Megafaunal extinctions

Several large Palearctic animals became extinct from the end of the

Pleistocene The Pleistocene ( , often referred to as the ''Ice age'') is the geological epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was finally confirmed in ...

into historic times, including

Irish elk The Irish elk (''Megaloceros giganteus''), also called the giant deer or Irish deer, is an extinct species of deer in the genus '' Megaloceros'' and is one of the largest deer that ever lived. Its range extended across Eurasia during the Pleist ...

(''Megaloceros giganteus''), aurochs (''Bos primigenius''),

woolly rhinoceros The woolly rhinoceros (''Coelodonta antiquitatis'') is an extinct species of rhinoceros that was common throughout Europe and Asia during the Pleistocene epoch and survived until the end of the last glacial period. The woolly rhinoceros was a me ...

(''Coelodonta antiquitatis''),

woolly mammoth The woolly mammoth (''Mammuthus primigenius'') is an extinct species of mammoth that lived during the Pleistocene until its extinction in the Holocene epoch. It was one of the last in a line of mammoth species, beginning with '' Mammuthus s ...

(''Mammuthus primigenius''),

North African elephant The North African elephant (''Loxodonta africana pharaohensis'') is an extinct possible subspecies of the African bush elephant (''Loxodonta africana''), or possibly a separate elephant species, that existed in North Africa, north of the Sahar ...

(''Loxodonta africana pharaoensis''),

Chinese elephant The existence of elephants in ancient China is attested both by archaeological evidence and by depictions in Chinese artwork. Long thought to belong to an extinct subspecies of the Asian elephant named ''Elephas maximus rubridens'', they lived in ...

(''Elephas maximus rubridens''),

cave bear The cave bear (''Ursus spelaeus'') is a prehistoric species of bear that lived in Europe and Asia during the Pleistocene and became extinct about 24,000 years ago during the Last Glacial Maximum. Both the word "cave" and the scientific name ' ...

(''Ursus spelaeus''), Straight tusked elephant (Palaeoloxodon antiquus) and European lion (''Panthera leo europaea'').

Palearctic terrestrial ecoregions

References

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 The University of Iowa Press is a university press that is part of the University of Iowa. Established in 1969, thUniversity of Iowa Pressis an academic publisher of poetry, short fiction, and creative nonfiction. The UI Press is the only universit ...

, pp. 203–227, 1989. * Buckland, P.C., et al. "Holt in Eyjafjasveit, Iceland: a paleoecological study of the impact of Landnám" in ''

Acta Archaeologica ''Acta Archaeologica'' is a peer-reviewed academic journal covering new discoveries of archaeological analysis. The journal is published in English, French, German, and Italian and is published by Denmark. Abstracting and indexing The journal ...

'' 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.

External links

Avionary
1500 Bird species of the Western and Central Palaearctic in 46 languages
Map of the ecozones
* http://www.bbc.co.uk/nature/ecozones/Palearctic_ecozone * https://web.archive.org/web/20150923233335/http://www.economicexpert.com/a/Tigris.htm * http://www.Merriam-Webster.com * http://www.Canadianbiodiversity.mcgill.ca {{Authority control Biogeography . * . Biogeographic realms * Natural history of Asia Natural history of Europe Natural history of Africa Phytogeography