All Topics  
Nearctic

 

 
   Email Print
   Bookmark   Link
 

 

Nearctic
 
 
  Topics Nearctic Topic Home

The Nearctic is one of the eight terrestrial ecozone
Ecozone

An ecozone or biogeographic realm is the largest scale biogeography division of the earth's surface based on the historic and evolutionary distribution patterns of plants and animals....
s dividing the Earth's land surface.

The Nearctic ecozone covers most of North America
North America

North America is the northern continent of the Americas, situated in the Earth's northern hemisphere and almost totally in the western hemisphere....
, including Greenland
Greenland

Greenland is a member country of the Kingdom of Denmark located between the Arctic Ocean and Atlantic Oceans, east of the Canadian Arctic Archipelago....
 and the highlands of Mexico
Mexico

The United Mexican States , commonly known as Mexico , is a federalism constitutionalism republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of Mexico....
. Southern Mexico, southern Florida
Florida

Florida is a U.S. state located in the Southeastern United States of the United States, bordering Alabama to the northwest and Georgia to the northeast....
, Central America
Central America

Central America is a central geography region of the Americas. It is the southernmost, isthmus portion of the North American continent, which connects with South America on the southeast....
, and the Caribbean
Caribbean

The Caribbean is a region consisting of the Caribbean Sea, its islands , and the surrounding coasts. The region is located southeast of the Gulf of Mexico and Northern America, east of Central America, and to the north of South America....
 islands are part of the Neotropic
Neotropic

In biogeography, Neotropic or Neotropical refers to one of the world's eight terrestrial ecozones.This ecozone includes South and Central America, the Mexico lowlands, the Caribbean islands, and southern Florida, because these regions share a large number of plant and animal groups....
 ecozone, together with South America
South America

South America is the southern continent of the Americas, situated entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere....
.

World Wide Fund for Nature
World Wide Fund for Nature

The World Wide Fund for Nature is an Internationalism non-governmental organization for the Conservation biology, Environmental science and Restoration ecology of the environment , formerly named the World Wildlife Fund, which remains its official name in the United States and Canada....
 (WWF) divides the Nearctic into four Bioregions, defined as "geographic clusters of ecoregions that may span several habitat types, but have strong biogeographic affinities, particularly at taxonomic levels higher than the species level (genus, family)."

Canadian Shield bioregion extends across the northern portion of the continent, from the Aleutian Islands
Aleutian Islands

The Aleutian Islands are a chain of more than 300 small volcanic islands forming a volcanic arc in the Northern Pacific Ocean, occupying an area of 6,821 sq mi and extending about 1,200 mi westward from the Alaska Peninsula toward the Kamchatka Peninsula....
 to Newfoundland
Newfoundland and Labrador

Newfoundland and Labrador is a Provinces and territories of Canada of Canada, on the country's Atlantic Ocean coast in northeastern North America....
.






Discussion
Ask a question about 'Nearctic'
Start a new discussion about 'Nearctic'
Answer questions from other users
Full Discussion Forum



Encyclopedia


The Nearctic is one of the eight terrestrial ecozone
Ecozone

An ecozone or biogeographic realm is the largest scale biogeography division of the earth's surface based on the historic and evolutionary distribution patterns of plants and animals....
s dividing the Earth's land surface.

The Nearctic ecozone covers most of North America
North America

North America is the northern continent of the Americas, situated in the Earth's northern hemisphere and almost totally in the western hemisphere....
, including Greenland
Greenland

Greenland is a member country of the Kingdom of Denmark located between the Arctic Ocean and Atlantic Oceans, east of the Canadian Arctic Archipelago....
 and the highlands of Mexico
Mexico

The United Mexican States , commonly known as Mexico , is a federalism constitutionalism republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of Mexico....
. Southern Mexico, southern Florida
Florida

Florida is a U.S. state located in the Southeastern United States of the United States, bordering Alabama to the northwest and Georgia to the northeast....
, Central America
Central America

Central America is a central geography region of the Americas. It is the southernmost, isthmus portion of the North American continent, which connects with South America on the southeast....
, and the Caribbean
Caribbean

The Caribbean is a region consisting of the Caribbean Sea, its islands , and the surrounding coasts. The region is located southeast of the Gulf of Mexico and Northern America, east of Central America, and to the north of South America....
 islands are part of the Neotropic
Neotropic

In biogeography, Neotropic or Neotropical refers to one of the world's eight terrestrial ecozones.This ecozone includes South and Central America, the Mexico lowlands, the Caribbean islands, and southern Florida, because these regions share a large number of plant and animal groups....
 ecozone, together with South America
South America

South America is the southern continent of the Americas, situated entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere....
.

Major ecological regions

The World Wide Fund for Nature
World Wide Fund for Nature

The World Wide Fund for Nature is an Internationalism non-governmental organization for the Conservation biology, Environmental science and Restoration ecology of the environment , formerly named the World Wildlife Fund, which remains its official name in the United States and Canada....
 (WWF) divides the Nearctic into four Bioregions, defined as "geographic clusters of ecoregions that may span several habitat types, but have strong biogeographic affinities, particularly at taxonomic levels higher than the species level (genus, family)."

Canadian Shield

The Canadian Shield bioregion extends across the northern portion of the continent, from the Aleutian Islands
Aleutian Islands

The Aleutian Islands are a chain of more than 300 small volcanic islands forming a volcanic arc in the Northern Pacific Ocean, occupying an area of 6,821 sq mi and extending about 1,200 mi westward from the Alaska Peninsula toward the Kamchatka Peninsula....
 to Newfoundland
Newfoundland and Labrador

Newfoundland and Labrador is a Provinces and territories of Canada of Canada, on the country's Atlantic Ocean coast in northeastern North America....
. It includes the Nearctic's Arctic Tundra and Boreal forest ecoregions.

In terms of floristic province
Floristic province

A Phytochorion, in phytogeography, is a geographic area with a relatively uniform composition of plant species. Adjacent phtyochoria do not usually have a sharp boundary, but rather a soft one, a transitional area in which many species from both regions overlap....
s, it is represented by part of the Canadian Province of the Circumboreal Region
Circumboreal Region

The Circumboreal Region is a floristic region within the Holarctic Kingdom in Eurasia and North America, as delineated by such geobotanists as Josias Braun-Blanquet and Armen Takhtajan....
.

Eastern North America


The Eastern North America bioregion includes the Temperate broadleaf and mixed forests
Temperate broadleaf and mixed forests

Temperate broadleaf and mixed forests are a temperate and humid biome. The typical structure of these forests include four layers. The upper most layer is the canopy which is composed of tall mature trees....
 of the eastern United States and southeastern Canada, the Great Plains
Great Plains

The Great Plains are the broad expanse of prairie and steppe which lie west of the Mississippi River and east of the Rocky Mountains in the United States and Canada....
 temperate grasslands
Temperate grasslands, savannas, and shrublands

Temperate grasslands, savannas, and shrublands is a biome whose predominant vegetation consists of grasses and/or shrubs. The climate is temperate and semi-arid to semi-humid....
 of the central United States and south-central Canada, and the Temperate coniferous forests
Temperate coniferous forests

Temperate coniferous forest is a terrestrial ecoregion biome found in temperate regions of the world with warm summers and cool winters and adequate rainfall to sustain a forest....
 of the southeastern United States.

In terms of floristic province
Floristic province

A Phytochorion, in phytogeography, is a geographic area with a relatively uniform composition of plant species. Adjacent phtyochoria do not usually have a sharp boundary, but rather a soft one, a transitional area in which many species from both regions overlap....
s, it is represented by the North American Atlantic Region
North American Atlantic Region

North American Atlantic Region is a floristic region within the Holarctic Kingdom identified by Armen Takhtajan and Robert F. Thorne, spanning from the East Coast of the United States and Gulf Coast of the United States coasts to the Great Plains and comprising a major part of the United States and southeastern portions of Canada....
 and part of the Canadian Province of the Circumboreal Region
Circumboreal Region

The Circumboreal Region is a floristic region within the Holarctic Kingdom in Eurasia and North America, as delineated by such geobotanists as Josias Braun-Blanquet and Armen Takhtajan....
.

Western North America

The Western North America bioregion includes the Temperate coniferous forests
Temperate coniferous forests

Temperate coniferous forest is a terrestrial ecoregion biome found in temperate regions of the world with warm summers and cool winters and adequate rainfall to sustain a forest....
 of the coastal and mountain regions of southern Alaska, western Canada, and the western United States from the Pacific to the Rocky Mountains
Rocky Mountains

The Rocky Mountains, often called the Rockies, are a mountain range in western North America. The Rocky Mountains stretch more than 4,800 kilometre from the northernmost part of British Columbia, in Canada, to New Mexico, in the United States....
, as well as the cold-winter intermountain deserts and xeric shrublands
Deserts and xeric shrublands

Desert and xeric shrublands is a biome characterized by, relating to, or requiring only a small amount of moisture. Deserts and xeric shrublands receive an annual average rainfall of ten inches or less, and have an arid or hyperarid climate, characterized by a strong moisture deficit, where annual potential loss of moisture from evapotransp...
 and temperate grasslands and shrublands of the western United States
Western United States

The Western United States—commonly referred to as the American West or simply The West—traditionally refers to the region comprising the westernmost U.S....
.

In terms of floristic province
Floristic province

A Phytochorion, in phytogeography, is a geographic area with a relatively uniform composition of plant species. Adjacent phtyochoria do not usually have a sharp boundary, but rather a soft one, a transitional area in which many species from both regions overlap....
s, it is represented by the Rocky Mountain Region
Rocky Mountain Region

The Rocky Mountain Region is a floristic region within the Holarctic Kingdom in western North America delineated by Armen Takhtajan and Robert F....
.

Northern Mexico

The Northern Mexico bioregion includes the mild-winter to cold-winter deserts and xeric shrublands of northern Mexico and the southwestern United States, including the Chihuahuan
Chihuahuan Desert

The Chihuahuan Desert is a desert that straddles the U.S.-Mexico border. On the United States side it occupies the valleys and basins of central and southern New Mexico, Texas west of the Pecos River and southeastern Arizona; south of the border, it covers the northern half of the Mexico Mexican state of Chihuahua , most of Coahuila, north-e...
, Sonoran
Sonoran Desert

The Sonoran Desert is a North American desert which straddles part of the United States-Mexico border and covers large parts of the U.S. states of Arizona and California and the Mexican states of Sonora and Baja California....
, and Mojave
Mojave Desert

The Mojave Desert , , locally referred to as the High Desert, occupies a significant portion of southeastern California and smaller parts of central California, southern Nevada, and northwestern Arizona, in the United States....
 deserts, as well as the Mediterranean climate
Mediterranean climate

A Mediterranean climate is one that resembles the climate of the lands in the Mediterranean Basin, which includes over half of the area with this climate type world-wide....
 California chaparral and woodlands
California chaparral and woodlands

The California chaparral and woodlands is a terrestrial ecoregion of central and southern California and northwestern Baja California , located on the west coast of North America....
 and the warm temperate and subtropical pine and pine-oak forests, including the Arizona Mountains forests and the Sierra Madre Occidental
Sierra Madre Occidental pine-oak forests

The Sierra Madre Occidental pine-oak forests are a tropical and subtropical coniferous forests terrestrial ecoregion of the Sierra Madre Occidental range of Mexico and the southwestern United States....
, Sierra Madre Oriental
Sierra Madre Oriental pine-oak forests

The Sierra Madre Oriental pine-oak forests are a tropical and subtropical coniferous forests ecoregion of northeastern Mexico, extending into the state of Texas in the United States....
, and Sierra Juarez and San Pedro Martir
Sierra Juarez and San Pedro Martir pine-oak forests

The Sierra Ju?rez and San Pedro M?rtir pine-oak forests is an ecoregion that covers the higher elevations of the Sierra Ju?rez and Sierra San Pedro M?rtir ranges of the northern Baja California Peninsula in Mexico, near the border with California ....
 pine-oak forests.

In terms of floristic province
Floristic province

A Phytochorion, in phytogeography, is a geographic area with a relatively uniform composition of plant species. Adjacent phtyochoria do not usually have a sharp boundary, but rather a soft one, a transitional area in which many species from both regions overlap....
s, it is represented by the Madrean Region
Madrean Region

The Madrean Region is a floristic region within the Holarctic Kingdom in North America, as delineated by Armen Takhtajan and Robert F. Thorne. It occupies arid or semiarid areas in the southwestern United States and northwestern Mexico and is bordered by the Rocky Mountain Region and North American Atlantic Region of the Holarctic Kingdom in...
.

History

Although North America and South America are presently joined by the Isthmus of Panama
Isthmus of Panama

The Isthmus of Panama, also historically known as the Isthmus of Darien, is the narrow strip of land that lies between the Caribbean Sea and the Pacific Ocean, linking North America and South America....
, these continents were separated for about 180 million years, and evolved very different plant and animal lineages. When the ancient supercontinent of Pangaea
Pangaea

Pangaea, Pang?a or Pangea was the supercontinent that existed during the Paleozoic and Mesozoic eras about 250 million years ago, before the component continents were separated into their current configuration....
 split into two about 180 million years ago, North America remained joined to Eurasia
Eurasia

Eurasia is a large landmass covering about 53,990,000 km? or about 10.6% of the Earth's surface . Often considered a single continent, Eurasia comprises the traditional continents of Europe and Asia, concepts which date back to classical antiquity and the borders for which are somewhat arbitrary....
 as part of the supercontinent of Laurasia
Laurasia

Laurasia was a supercontinent that most recently existed as a part of the split of the Pangaean supercontinent in the late Mesozoic era . It included most of the landmasses which make up today's continents of the northern hemisphere, chiefly Laurentia , Baltica, Siberia , Kazakhstania, and the North China Craton and East China Craton craton...
, while South America was part of the supercontinent of Gondwana
Gondwana

Gondwana , originally Gondwanaland is the name given to a southern precursor-supercontinent and then as a remnant separated from Laurasia 180- during the breakup of the Pangaea supercontinent that existed about 500 to 200 Annum ago into two large segments.. North America later split from Eurasia. North America has been joined by land bridges to both Asia
Asia

Asia is the world's largest and most populous continent. It covers 8.6% of the Earth's total surface area and, with over 4 billion people, it contains more than 60% of the world's current human population....
 and South America since then, which allowed an exchange of plant and animal species
Species

In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring....
 between the continents, the Great American Interchange
Great American Interchange

The Great American Interchange was an important zoogeography event in which land and freshwater fauna migrated from North America via Central America to South America and vice versa, as the volcanic Isthmus of Panama rose up from the sea floor and bridged the formerly separated continents....
.

A former land bridge across the Bering Strait
Bering Strait

The Bering Strait is a sea strait between Cape Dezhnev, Chukotka Autonomous Okrug, the easternmost point of the Asian continent and Cape Prince of Wales, Alaska, the westernmost point of the North American continent, with latitude of about 65? 40' north, slightly south of the polar circle....
 between Asia and North America allowed many plants and animals to move between these continents, and the Nearctic ecozone shares many plants and animals with the Palearctic
Palearctic

The Palearctic or Palaearctic is one of the eight ecozones dividing the Earth surface.Physically, the Palearctic is the largest ecozone....
. The two ecozones are sometimes included in a single Holarctic
Holarctic

The Holarctic ecozone refers to the habitats found throughout the northern continents of the world as a whole. This region is divided into the Palearctic, consisting of Northern Africa and all of Eurasia, with the exception of Southeast Asia and the Indian subcontinent, and the Nearctic, consisting of North America south to northern Mexico....
 ecozone.

Many large animals, or megafauna
Megafauna

The term megafauna has two distinct meanings in the biological sciences. The less commonly found meaning is of any animal which can be seen with the unaided eye, in contrast to microfauna....
, including horse
Horse

The horse is a hoofed mammal, a subspecies of one of seven extant species of the family Equidae. The horse has evolution of the horse over the past 45 to 55 million years from a small multi-toed creature into the large, odd-toed ungulate animal of today....
s, camel
Camel

Camels are even-toed ungulates within the genus Camelus. The dromedary, one-humped or Arabian camel has a single hump and is well known for its healthy low fat milk, and the Bactrian camel has two humps....
s, mammoth
Mammoth

A mammoth is any species of the extinct genus Mammuthus. These proboscideans are members of the Elephantidae and close relatives of modern elephants....
s, mastodonts, ground sloth
Ground sloth

Ground sloths are a diverse group of extinct sloths, mammals in the edentate superorder Xenarthra. They may have died out as recently as 1550 AD in Hispaniola and Cuba, but had long since been extinct on the mainland of North America and South America....
s, sabre-tooth cats (Smilodon
Smilodon

Smilodon , sometimes called sabre-toothed cat, is an extinction genus of large Machairodontinae saber-toothed cats that lived between approximately 2.5 million to 10,000 years ago in North America and South America....
), the giant short-faced bear
Bear

Bears are mammals of the family Ursidae. Bears are classified as caniforms, or doglike carnivorans, with the pinnipeds being their closest living relatives....
 (Arctodus simius), and the cheetah
Cheetah

The cheetah is an atypical member of the cat family that is unique in its speed, while lacking climbing abilities. Therefore it is placed in its own genus, Acinonyx....
, became extinct in North America at the end of the Pleistocene
Pleistocene

The Pleistocene is the epoch from 1.8 million to 10,000 years Before Present covering the world's recent period of repeated glaciations. The name pleistocene is derived from the Greek and ....
 epoch (ice ages), at the same time the first evidence of humans appeared, in what is called the Holocene extinction event
Holocene extinction event

The Holocene extinction event is the widespread, ongoing mass extinction of species during the modern Holocene epoch . The large number of extinctions span numerous families of plants and animals including mammals, birds, amphibians, reptiles and arthropods; a sizeable fraction of these extinctions are occurring in the rainforests....
. Previously, it was believed that the megafaunal extinctions were caused by the changing climate, but many scientists now believe that while the climate change contributed to these extinctions, the primary cause was hunting by newly-arrived humans or, in the case of some large predators, extinction resulting from prey becoming scarce. The American bison
American Bison

The American Bison is a bovinae mammal, also commonly known as the American buffalo. "Buffalo" is somewhat of a misnomer for this animal, as it is only distantly related to either of the two "true buffaloes", the Wild Asian Water Buffalo and the African buffalo....
 (Bison bison), brown bear
Brown Bear

The Brown Bear is a large bear distributed across much of northern Eurasia and North America. It weighs 100 to 700 kg and its larger populations such as the Kodiak bear match the Polar bear as the largest extant land predator....
 or grizzly bear (Ursus arctos), and elk
Elk

Elk may refer to:* Various species of deer:** European Elk , also known as Moose** North American Elk , also known as Wapiti** Indian Elk , also known as sambar ...
 or wapiti (Cervus canadensis) entered North America around the same time as the first humans, and expanded rapidly, filling ecological niches left empty by the newly-extinct North American megafauna.

Flora and fauna


Flora and fauna that originated in the Nearctic

Animals originally unique to the Nearctic include:
  • Family Canidae
    Canidae

    Canidae is the family of the dogs; a member of this family is called a canid. They include wolf, foxes, coyotes, and jackals. The Canidae family is divided into the "true dogs" of the tribe Canini and the "foxes" of the tribe Vulpini....
    , dog
    Dog

    The dog is a domesticated subspecies of the Gray Wolf, a member of the Canidae family of the order Carnivora. The term is used for both feral and pet varieties....
    s, wolves, foxes
    Fox

    A fox is an animal belonging to any one of about 27 species of small to medium-sized Canidae, characterized by possessing a long, narrow snout, and a bushy tail, or brush....
    , and coyote
    Coyote

    The coyote , also known as the prairie wolf, is a species of canid found throughout North America and Central America, ranging from Panama in the south, north through Mexico, the United States, and Canada....
    s
  • Family Camelidae, camel
    Camel

    Camels are even-toed ungulates within the genus Camelus. The dromedary, one-humped or Arabian camel has a single hump and is well known for its healthy low fat milk, and the Bactrian camel has two humps....
    s and their South American relatives including the llama
    Llama

    The llama is a South American camelid, widely used as a pack animal by the Incas and other natives of the Andes mountains. In South America llamas are still used as beasts of burden, as well as for the production of fiber and meat....
    . The last North American Camelids went extinct during the last ice age.
  • Family Equidae
    Equidae

    Equidae is the Taxonomy Family of horses and related animals, including the extant horses, donkeys, and zebras, and many other species known only from fossils....
    , horse
    Horse

    The horse is a hoofed mammal, a subspecies of one of seven extant species of the family Equidae. The horse has evolution of the horse over the past 45 to 55 million years from a small multi-toed creature into the large, odd-toed ungulate animal of today....
    s and their relatives.
  • Family Antilocapridae, which includes the pronghorn
    Pronghorn

    The pronghorn , also pronghorn antelope or prong buck, is a species of ungulate mammal native to interior western and central North America....
  • Tremarctine, or short-faced, bears, including the extinct giant short-faced bear (Arctodus simius). The last remaining member of the group is the spectacled bear
    Spectacled Bear

    The Spectacled Bear , also known as the Andean Bear and locally as ukuko, jukumari or ucumari, is the closest living kin of the Arctodus of the Middle Pleistocene to Late Pleistocene age....
     (Tremarctos ornatus) of South America.
  • The now-extinct American cheetah (Miracinonyx)


Flora and fauna endemic to the Nearctic

One bird
Bird

Birds are wing, Bipedalismal, endothermic , vertebrate animals that lay egg . There are around 10,000 living species, making them the most numerous tetrapod vertebrates....
 family, the wrentits (Timaliinae), is endemic to the Nearctic region. The Holarctic has four endemic families: divers
Loon

The loons or divers are a group of aquatic birds found in many parts of North America and northern Eurasia. All living species of loons are members of one genus, Gavia, family , Gaviidae, and order Gaviiformes all of their own....
 (Gaviidae), grouse
Grouse

Grouse are a group of birds from the order Galliformes. They are often considered a family Tetraonidae, though the American Ornithologists' Union and many others include grouse as a subfamily Tetraoninae in the family Phasianidae....
 (Tetraoninae), auk
Auk

Auks are birds of the family Alcidae in the order Charadriiformes. They are superficially similar to penguins due to their black-and-white colours, their upright posture and some of their habits....
s (Alcidae), and the waxwing
Waxwing

The waxwings form the genus Bombycilla of perching bird birds. According to most authorities, this is the only genus placed in the family Bombycillidae....
s (Bombycillidae). The scarab beetle families Pleocomidae and Diphyllostomatidae (Coleoptera) are also endemic to the Nearctic.

Plants families endemic or nearly endemic to the Nearctic include Crossosomataceae
Crossosomataceae

Crossosomataceae is a small plant family, consisting of three genus of shrubs found only in the dry parts of the United States southwest and Mexico....
, Simmondsiaceae
Simmondsiaceae

Simmondsiaceae or the Jojoba Family is a family of flowering plants. The family is not recognized by all taxonomic systems, the single species, Simmondsia chinensis, often being treated as belonging to family Buxaceae....
, and Limnanthaceae
Limnanthaceae

Limnanthaceae is a family of plants in the order Brassicales. It contains two genera totalling eight species. One of the better known plants in the family is the Poached egg plant ....
.

Nearctic Terrestrial Ecoregions


External links