
The Palearctic or Palaearctic is the largest of the eight
biogeographic realms of the Earth. It stretches across all of
Eurasia north of the foothills of the
Himalayas, and
North Africa.
The realm consists of several
bioregions: the
Euro-Siberian region; the
Mediterranean Basin
In biogeography, the Mediterranean Basin (; 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 w ...
; the
Sahara
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, photo_caption = The Sahara taken by Apollo 17 astronauts, 1972
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and
Arabian Deserts; and
Western,
Central
Central is an adjective usually referring to being in the center of some place or (mathematical) object.
Central may also refer to:
Directions and generalised locations
* Central Africa, a region in the centre of Africa continent, also known as ...
and
East Asia. 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
Zoogeography is the branch of the science of biogeography that is concerned with geographic distribution (present and past) of animal species.
As a multifaceted field of study, zoogeography incorporates methods of molecular biology, genetics, mo ...
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
Australasian is the adjectival form of Australasia, a geographical region including Australia
Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continen ...
,
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
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 v ...
.
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
The Bering Sea (, ; rus, Бе́рингово мо́ре, r=Béringovo móre) is a marginal sea of the Northern Pacific Ocean. It forms, along with the Bering Strait, the divide between the two largest landmasses on Earth: Eurasia and The Ameri ...
.
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
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 t ...
of
North America
North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...
. Eurasia and North America were often connected by the
Bering land bridge, and have very similar
mammal
Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fur or ...
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 region ...
. 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
In biogeography, the Mediterranean Basin (; 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 w ...
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
Mediterranean forests, woodlands, and scrub is a biome defined by the World Wide Fund for Nature. The biome is generally characterized by dry summers and rainy winters, although in some areas rainfall may be uniform. Summers are typically hot in ...
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
Chaparral ( ) is a shrubland plant community and geographical feature found primarily in the U.S. state of California, in southern Oregon, and in the northern portion of the Baja California Peninsula in Mexico. It is shaped by a Mediterranean c ...
,
matorral
300px, Springtime in Chilean matorral a few kilometers north of Santiago along the Pan-American Highway
Matorral is a Spanish language, Spanish word, along with ''tomillares'', for shrubland, thicket or bushes. It is used in naming and describin ...
,
maquis
Maquis may refer to:
Resistance groups
* Maquis (World War II), predominantly rural guerrilla bands of the French Resistance
* Spanish Maquis, guerrillas who fought against Francoist Spain in the aftermath of the Spanish Civil War
* The network ...
, or
garrigue.
Conservation International
Conservation International (CI) is an American nonprofit environmental organization headquartered in Crystal City, Arlington, Virginia.
CI's work focuses on science, policy and partnership with businesses, governments and communities. The organ ...
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
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
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, photo_caption = The Sahara taken by Apollo 17 astronauts, 1972
, map =
, map_image =
, location =
, country =
, country1 =
, ...
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 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 Paci ...
s of the
Euxine-Colchic deciduous forests ecoregion.
Central Asia and the
Iranian plateau are home to dry
steppe
In physical geography, a steppe () is an ecoregion characterized by grassland plains without trees apart from those near rivers and lakes.
Steppe biomes may include:
* the montane grasslands and shrublands biome
* the temperate grasslands, ...
grasslands
A grassland is an area where the vegetation is dominated by grasses (Poaceae). However, sedge (Cyperaceae) and rush (Juncaceae) can also be found along with variable proportions of legumes, like clover, and other herbs. Grasslands occur natural ...
and
desert
A desert is a barren area of landscape where little precipitation occurs and, consequently, living conditions are hostile for plant and animal life. The lack of vegetation exposes the unprotected surface of the ground to denudation. About on ...
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 2000–2500 m form the boundary between the Palearctic and
Indomalaya ecoregions.
East Asia
China
China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and ...
,
Korea and
Japan
Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...
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 The Mountains of Southwest China is a biodiversity hotspot designated by Conservation International which includes several temperate coniferous forests in southwestern China, which lie in the river valleys on the southeastern corner of the Tibetan ...
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
China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and ...
. Isolated small outposts (
sky islands) 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 (on
Fan Si Pan
Fansipan (Vietnamese: ''Phan Xi Păng'', ) is a mountain in Vietnam. The height of the mountain was in 1909, but now the height of the mountain is . It is the highest mountain in the Indochinese Peninsula (comprising Vietnam, Laos, and Cambodia) ...
, 3140 m) and the high mountains of
Taiwan.
Freshwater
The realm contains several important
freshwater ecoregions as well, including the heavily developed
rivers of Europe
This article lists the principal rivers of Europe with their main tributaries.
Scope
The border of Europe and Asia is here defined as from the Kara Sea, along the Ural Mountains and Ural River to the Caspian Sea. While the crest of the Caucas ...
, 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,
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, and
Caspian seas,
Siberia's
Lake Baikal
Lake Baikal (, russian: Oзеро Байкал, Ozero Baykal ); mn, Байгал нуур, Baigal nuur) is a rift lake in Russia. It is situated in southern Siberia, between the federal subjects of Irkutsk Oblast to the northwest and the Repu ...
, the oldest and deepest lake on the planet, and Japan's ancient
Lake Biwa.
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 has four other endemic bird families: the divers or
loon
Loons (North American English) or divers (British / Irish English) are a group of aquatic birds found in much of North America and northern Eurasia. All living species of loons are members of the genus ''Gavia'', family Gaviidae and order Gavi ...
s (Gaviidae),
grouse (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
Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fur or ...
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
The elk (''Cervus canadensis''), also known as the wapiti, is one of the largest species within the deer family, Cervidae, and one of the largest terrestrial mammals in its native range of North America and Central and East Asia. The common ...
(''Cervus canadensis'') in far eastern Siberia,
American bison (''Bison bison''), and
reindeer (''Rangifer tarandus'', known in North America as the
caribou
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 subspe ...
).
Megafaunal extinctions
Several large Palearctic animals became extinct from the end of the
Pleistocene into historic times, including
Irish elk (''Megaloceros giganteus''),
aurochs
The aurochs (''Bos primigenius'') ( or ) is an extinct cattle species, considered to be the wild ancestor of modern domestic cattle. With a shoulder height of up to in bulls and in cows, it was one of the largest herbivores in the Holocen ...
(''Bos primigenius''),
woolly rhinoceros (''Coelodonta antiquitatis''),
woolly mammoth (''Mammuthus primigenius''),
North African elephant (''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 (''Ursus spelaeus''),
Straight tusked elephant (Palaeoloxodon antiquus) and
European lion
The history of lions in Europe is based on fossils of Pleistocene and Holocene lions excavated in Europe since the early 19th century.
The first lion fossil was excavated in southern Germany, and described by Georg August Goldfuss using the sci ...
(''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, 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.
External links
Avionary1500 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
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Biogeography
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*
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Biogeographic realms
*
Natural history of Asia
Natural history of Europe
Natural history of Africa
Phytogeography