The Holarctic , or Holarctic region (from other Greek речλος - whole, whole and ἄρκτος - north) is a biogeographic region, distinguished in floristic and faunistic zoning . It covers most of the Northern Hemisphere and is the largest of all biogeographic regions. The southern border of the Holarctic passes through the north of Mexico , includes the islands of Cape Verde , passes further along the northern edge of the Sahara , the Arabian Peninsula , the Himalayas , southern China , includes Taiwan and Japan .
Content
In floristic zoning
In the floristic zoning, the Holarctic has the status of a kingdom, divided into several kingdoms. There are different versions of its division.
Characteristic representatives of the Holarctic flora are the genera of the families Pine ( Pinaceae ), Birch ( Betulaceae ), Beech ( Fagaceae ), Willow ( Salicaceae ), as well as Ranunculaceae ( Ranunculaceae ) and Pink ( Rosaceae ). Cabbage ( Brassicaceae ), Cloves ( Caryophyllaceae ), Sitnikovye ( Juncaceae ) and Sedge ( Cyperaceae ) are found mainly in the Holarctic.
Pleistocene icing led to the depletion of the flora of Europe . Most of the flora found here in the Pliocene has died out. Some families, such as Magnoliaceae , Hamamelidaceae , and Styracaceae, remained only in North America and Asia .
In faunistic zoning
In the faunal zoning of the Holarctic or Arctogei [1] it is divided into two regions: the Nearctic and the Palearctic . There is no clear border in the south, but there is a transition zone to other biogeographic regions. Central America belongs to it on the American continent, and the Sahara on the African continent. In West Asia, the transition zone is the Arabian Peninsula, not counting its southern part.
The characteristic mammals of the Holarctic are moose ( Alcinae ), deer ( Cervinae ), lynx ( Lynx ), goats ( Caprinae ), beavers ( Castoridae ), moles ( Ochotonidae ), moles ( Talpidae ), shrews ( Soricidae ), jerboa ( Zapodina ) ( Arvicolinae ). Typical bird families are black grouse ( Tetraoninae ), auket ( Alcidae ), and waxwing ( Bombycillidae ). Among insects in the Holarctic, families of butterflies, thick-headed , lycaenidae , scoops , crested nymphalids , nymphalids , whites , marigolds and hawks are found .
Subareas
- Euro-Siberian subregion - fully covers the zone of mixed forests and taiga in Europe and Asia. Endemic to this subregion: various species of shrew , roe deer , sable , flying squirrel , common squirrel , common lynx , Asian chipmunk , beaver , forest lemmming , forest voles .
- The East Asian , or Manchurian , subregion - covers East Asia south of the Amur River , including the Primorsky Territory . Endemic: giant shrew , giant shrew , eastern moles , gorilla , white-breasted bear , harza , long-tailed mouse , rat-like hamster , different types of voles [2] .
Notes
- ↑ Biological dictionary
- ↑ Mammals. Big Encyclopedic Dictionary / scientific. ed.d. n I. Y. Pavlinov . - M .: ACT, 1999 .-- S. 48, 76 .-- 416 p. - ISBN 5-237-03132-3 .
Literature
- Takhtadzhyan A. L. Floristic regions of the Earth / USSR Academy of Sciences. Bot. Institute of them. V. L. Komarova. - L .: Science, Len. Dep., 1978.- 247 p.
- Holarctic region // Dictionary of botanical terms / Ed. ed. I.A. Dudki. - Kiev: Naukova Dumka, 1984.