Everything about Palaearctic totally explained
The
Palearctic or
Palaearctic is one of the eight
ecozones dividing the Earth surface.
Physically, the Palearctic is the largest ecozone. It includes the
terrestrial ecoregions of Europe, Asia north of the
Himalaya foothills, northern Africa, and the northern and central parts of the
Arabian Peninsula.
Major ecological regions
The Palearctic ecozone includes mostly
boreal and
temperate climate ecoregions, which run across
Eurasia from western Europe to the
Bering Sea.
European-Siberian region
The boreal and temperate European-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 European-Siberian region is characterized by many shared plant and animal species, and has many affinities with the temperate and boreal regions of the
Nearctic ecoregion 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 ecozone. 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 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 shrub 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, or 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 ecozone; other biogeographers identify the ecozone 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 2000-2500 m form the boundary between the Palearctic and
Indomalaya ecoregions.
China and Japan
China 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 wasn't 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 southern parts of China and Japan, 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
Myanmar and southern
China. Isolated small outposts (
sky islands) occur as far south as central Myanmar (on Mt. Victoria, 3050 m), northernmost
Vietnam (on Fan Si Pan, 3140 m) and the high mountains of
Taiwan.
Freshwater
The ecozone 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 ages, 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).
Palearctic terrestrial ecoregions
Further Information
Get more info on 'Palaearctic'.
|
External Link Exchanges
Do you know how hard it is to get a link from a large encyclopaedia? Well we're different and will prove it. To get a link from us just add the following HTML to your site on a relevant page:
<a href="http://palearctic_ecozone.totallyexplained.com">Palearctic ecozone Totally Explained</a>
Then simply click through this link from your web page. Our crawlers will verify your link, extract the title of your web page and instantly add a link back to it. If you like you can remove the words Totally Explained and embed the link in article text.
As long as your link remains in place, we'll keep our link to you right here. Please play fair - our crawlers are watching. Your site must be closely related to this one's topic. Any kind of spamming, dubious practises or removing the link will result in your link from us being dropped and, potentially, your whole site being banned. |