The range is older than the other major mountain range in North America, the Rocky Mountains of the west. Some of the outcrops in the Appalachians contain rocks formed during the Precambrian era. The geologic processes that led to the formation of the Appalachian Mountains started 1.1 billion years ago. The first mountain range in the region was created when the continents of Laurentia and Amazonia collided, creating a supercontinent called Rodinia. The collision of these continents caused the rocks to be folded and faulted, creating the first mountains in the region.[4][7] Many of the rocks and minerals that were formed during that event can currently be seen at the surface of the present Appalachian range.[8] Around 480 million years ago, geologic processes began that led to three distinct orogenic eras that created much of the surface structure seen in today's Appalachians. [d] During this period, mountains once reached elevations similar to those of the Alps and the Rockies before natural erosion occurred over the last 240 million years leading to what is present today.[9]
The Appalachian Mountains are a barrier to east–west travel, as they form a series of alternating ridgelines and valleys oriented in opposition to most highways and railroads running east–west. This barrier was extremely important in shaping the expansion of the United States in the colonial era.[10]
The range is the home of a very popular recreational feature, the Appalachian Trail. This is a 2,175-mile (3,500km) hiking trail that runs all the way from Mount Katahdin in Maine to Springer Mountain in Georgia, passing over or past a large part of the Appalachian range. The International Appalachian Trail is an extension of this hiking trail into the Canadian portion of the Appalachian range in New Brunswick and Quebec.
Etymology
While exploring inland along the northern coast of Florida in 1528, the members of the Narváez expedition, including Álvar Núñez Cabeza de Vaca, found a Native American village near present-day Tallahassee, Florida whose name they transcribed as Apalchen or Apalachen[a.paˈla.tʃɛn]. The name was soon altered by the Spanish to Apalachee and used as a name for the tribe and region spreading well inland to the north. Pánfilo de Narváez's expedition first entered Apalachee territory on June 15, 1528, and applied the name. Now spelled "Appalachian", it is the fourth-oldest surviving European place-name in the US.[11]
After the 1540 expedition of Hernando de Soto, Spanish cartographers began to apply the name of the tribe to the mountains themselves. The first cartographic appearance of Apalchen is on Diego Gutiérrez's map of 1562; the first use for the mountain range is the map of Jacques le Moyne de Morgues in 1565.[12]
Diego Gutiérrez's 1562 map of the Western Hemisphere showing the first known use of a variation of the place name Appalachia ("Apalchen") from his map, Americae sive qvartae orbis partis nova et exactissima descriptio
The name was not commonly used for the whole mountain range until the late 19th century. A competing and often more popular name was the "Allegheny Mountains", "Alleghenies", and even "Alleghania". In the early 19th century, Washington Irving proposed renaming the United States either Appalachia or Alleghania.[13]
In U.S. dialects in the southern regions of the Appalachians, the word is pronounced /ˌæpəˈlætʃɪnz/, with the third syllable sounding like "latch". In northern parts of the mountain range, it is pronounced /ˌæpəˈleɪtʃɪnz/ or /ˌæpəˈleɪʃɪnz/; the third syllable is like "lay", and the fourth "chins" or "shins".[14] There is often great debate between the residents of the regions regarding the correct pronunciation. Elsewhere, a commonly accepted pronunciation for the adjective Appalachian is /ˌæpəˈlætʃiən/, with the last two syllables "-ian" pronounced as in the word "Romanian".[15]
Geography
Appalachian Mountains broken down by physiographic division, provinces, and sections
Perhaps partly because the range runs through large portions of both the United States and Canada, and partly because the range was formed over numerous geologic time periods, one of which is sometimes termed the Appalachian orogeny, writing communities struggle to agree on an encyclopedic definition of the mountain range. However, each of the governments has an agency that informs the public about the major landforms that make up the countries, the United States Geological Survey (USGS) and the Geological Survey of Canada (GSC). The landforms are referred to as physiographic regions. The regions create precise boundaries from which maps can be drawn. The Appalachian Highlands is the name of one of the eight physiographic regions of the contiguous 48 United States.[16] The Appalachian Uplands is the name of one of seven physiographic regions of Canada.[17]
Appalachian Highlands of the United States
Appalachian Highlands physiographic provinces
The second level in the physiographic classification schema for the USGS is "province", the same word as Canada uses to divide its political subdivisions, meaning that the terminology used by the two countries do not match below the region level. The lowest level of classification is "section".[16]
Piedmont, including the Uplands and Lowlands sections
Blue Ridge, including the Northern and Southern sections
The Appalachian Uplands are one of the seven physiographic divisions in Canada. Canada's GSC does not use the same classification system as the USGS below the division level. The agency does break the divisions of the Appalachian Uplands into 13 subsections that are in four different political provinces of Canada.[18]
Nova Scotia contains the Atlantic Uplands, Nova Scotia Uplands, and the Annapolis Lowlands
New Brunswick contains the New Brunswick Highlands, the Chaleur Uplands, and the Maritime Plain
Quebec contains the Notre Dame Mountains, Eastern Quebec Uplands, Sutton Mountains, and Mégantic Hills
While the Appalachian Highlands and Appalachian Uplands are generally continuous across the U.S./Canadian border, the St. Lawrence Valley area is handled differently in the physiographic classification schemas. The part of the St. Lawrence Valley in the United States is one of the second-level classifications, part of the Appalachian Highlands. In Canada, the area is part of the first-level classification, the St. Lawrence Lowlands. This includes the area around the city of Montreal, Anticosti Island, and the northwest coastline of Newfoundland. The dissected plateau area, while not actually made up of geological mountains, is popularly called "mountains", especially in eastern Kentucky and West Virginia, and while the ridges are not high, the terrain is extremely rugged. In Ohio and New York, some of the plateau has been glaciated, which has rounded off the sharp ridges and filled the valleys to some extent. The glaciated regions are usually referred to as hill country rather than mountains.
The Appalachian belt includes the plateaus sloping southward to the Atlantic Ocean in New England, and southeastward to the border of the coastal plain through the central and southern Atlantic states; and on the northwest, the Allegheny and Cumberland plateaus declining toward the Great Lakes and the interior plains. A remarkable feature of the belt is the longitudinal chain of broad valleys, including the Great Appalachian Valley, which in the southerly sections divides the mountain system into two unequal portions, but in the northernmost lies west of all the ranges possessing typical Appalachian features, and separates them from the Adirondack group. The mountain system has no axis of dominating altitudes, but in every portion, the summits rise to rather uniform heights, and, especially in the central section, the various ridges and intermontane valleys have the same trend as the system itself. None of the summits reaches the region of perpetual snow.[19]
In Pennsylvania, there are over sixty summits that rise over 2,500ft (800m); the summits of Mount Davis and Blue Knob rise over 3,000ft (900m). In Maryland, Eagle Rock and Dans Mountain are conspicuous points reaching 3,162 and 2,882ft (964 and 878m) respectively. On the same side of the Great Valley, south of the Potomac, are the Pinnacle 3,007 feet (917m) and Pidgeon Roost 3,400ft (1,000m).[19] In West Virginia, more than 150 peaks rise above 4,000ft (1,200m), including Spruce Knob4,863ft (1,482m), the highest point in the Allegheny Mountains. A number of other points in the state rise above 4,800ft (1,500m). Cheat Mountain (Snowshoe Mountain) at Thorny Flat 4,848ft (1,478m) and Bald Knob4,842ft (1,476m) are among the more notable peaks in West Virginia.
The Blue Ridge Mountains, rising in southern Pennsylvania and there known as South Mountain, attain elevations of about 2,000ft (600m) in Pennsylvania. South Mountain achieves its highest point just below the Mason-Dixon line in Maryland at Quirauk Mountain2,145ft (654m) and then diminishes in height southward to the Potomac River. Once in Virginia, the Blue Ridge again reaches 2,000ft (600m) and higher. In the Virginia Blue Ridge, the following are some of the highest peaks north of the Roanoke River: Stony Man 4,031ft (1,229m), Hawksbill Mountain4,066ft (1,239m), Apple Orchard Mountain4,225ft (1,288m) and Peaks of Otter4,001 and 3,875ft (1,220 and 1,181m). South of the Roanoke River, along the Blue Ridge, are Virginia's highest peaks including Whitetop Mountain5,520ft (1,680m) and Mount Rogers5,729ft (1,746m), the highest point in the Commonwealth.
Chief summits in the southern section of the Blue Ridge are located along two main crests, the Western or Unaka Front along the Tennessee-North Carolina border and the Eastern Front in North Carolina, or one of several "cross ridges" between the two main crests. Major subranges of the Eastern Front include the Black Mountains, Great Craggy Mountains, and Great Balsam Mountains, and its chief summits include Grandfather Mountain5,964ft (1,818m) near the Tennessee-North Carolina border, Mount Mitchell6,684ft (2,037m) in the Blacks, and Black Balsam Knob6,214ft (1,894m) and Cold Mountain6,030ft (1,840m) in the Great Balsams. The Western Blue Ridge Front is subdivided into the Unaka Range, the Bald Mountains, the Great Smoky Mountains, and the Unicoi Mountains, and its major peaks include Roan Mountain6,285ft (1,916m) in the Unakas, Big Bald 5,516ft (1,681m) and Max Patch4,616ft (1,407m) in the Bald Mountains, Kuwohi6,643ft (2,025m), Mount Le Conte6,593 feet (2,010m), and Mount Guyot6,621ft (2,018m) in the Great Smokies, and Big Frog Mountain4,224ft (1,287m) near the Tennessee-Georgia-North Carolina border. Prominent summits in the cross ridges include Waterrock Knob (6,292ft (1,918m)) in the Plott Balsams. Across northern Georgia, numerous peaks exceed 4,000ft (1,200m), including Brasstown Bald, the state's highest, at 4,784-and-4,696ft (1,458-and-1,431m)Rabun Bald. In north-central Alabama, Mount Cheaha rises prominently to 1,445 feet (440m) over its surroundings, as part of the southernmost spur of the Blue Ridge Mountains.
Highest Peaks in each U.S. state and Canadian province in the Appalachian Mountains
Plate tectonics over the period dating back at least 1 billion years led to geological creation of the land that is now the Appalachian Mountain range. The continental movement led to collisions that built mountains and they later pulled apart creating oceans over parts of the continent that are now exposed.[22]
Grenville Orogeny and formation of Supercontinent Rodinia
The first mountain-building tectonic plate collision that initiated the construction of what are today the Appalachians occurred at least a billion years ago when the pre-North American craton called Laurentia collided with at least one other craton - Amazonia. All the other cratons of the earth also collided at about this time to form the supercontinent Rodinia and were surrounded by one single ocean. (It is possible that the cratons of Kalahari, and Rio Plato, were also part of that early collision since they were present as Rodinia broke up). Mountain-building referred to as the Grenville Orogeny occurred along the boundaries of the cratons.[4][23] The present Appalachian Mountains have at least two areas which are made from rock formations that were formed during this orogeny - the Blue Ridge Mountains and the Adirondacks.
Land added to Laurentia during the Grenville orogeny
Breakup of Rodinia and formation of the Iapetus Ocean
After the Grenville orogeny, the direction of the continental drift reversed, and the single supercontinent Rodinia began to break up. The mountains formed during the Grenvillian era underwent erosion due to weathering, glaciation, and other natural processes, resulting in the leveling of the landscape. The eroded sediments from these mountains contributed to the formation of sedimentary basins and valleys. For example, in what is now the southern United States, the Ococee Basin was formed. Seawater filled the basin. Rivers from the surrounding countryside carried clay, silt, sand, and gravel to the basin, much as rivers today carry sediment from the midcontinent region to the Gulf of Mexico. The sediment spread out in layers on the basin floor. The basin continued to subside, and over a long period of time, probably millions of years, a great thickness of sediment accumulated.[23] Eventually, the tectonic forces pulling the two continents apart became so strong that an ocean formed off the eastern coast of the Laurentian margin. This was called the Iapetus Ocean and was the precursor of the modern Atlantic Ocean. The rocks of the Valley and Ridge province formed over millions of years, in the Iapetus. Shells and other hard parts of ancient marine plants and animals accumulated to form limey deposits that later became limestone. This is the same process by which limestone forms in modern oceans. The weathering of limestone, now exposed at the land surface, produces the lime-rich soils that are so prevalent in the fertile farmland of the Valley and Ridge province.[23]
During this continental break-up, around 600 million to 560 million years ago, volcanic activity was present along the tectonic margins. There is evidence of this activity in today's Blue Ridge Mountains. Mount Rogers, Whitetop Mountain, and Pine Mountain are all the result of volcanic activity that occurred around this time.[24] Evidence of subsurface activity, dikes and sills intruding into the overlying rock, is present in the Blue Ridge as well. For instance, mafic rocks have been found along the Fries Fault in the central Blue Ridge area of Montgomery County, VA.[25]
Taconic Orogeny
Taconic orogeny
The Iapetus continued to expand and during that time bacteria, algae, and many species of invertebrates flourished in the oceans, but there were no plants or animals on land. Then, during the middle Ordovician Period about 500 to 470 million years ago, the motion of the crustal plates changed, and the continents began to move back toward each other. The once-quiet Appalachian passive margin changed to a very active plate boundary when a neighboring Iapetus oceanic plate containing a volcanic arc collided with and began sinking beneath the North American craton. Volcanoes grew along the continental margin coincident with the initiation of subduction. Thrust faulting uplifted and warped older sedimentary rock laid down on the passive margin. As the mountains rose, erosion began to wear them down over time. Streams carried rock debris downslope to be deposited in nearby lowlands.[26] The Taconic orogeny ended after about 60 million years, but built much of the land mass that is now New England and southwestward to Pennsylvania.
The Taconic Orogeny was the second of four mountain building plate collisions that contributed to the formation of the Appalachians, culminating in the collision of North America and Africa (see Alleghanian orogeny).[27]
Acadian Orogeny
The third mountain-building event was the Acadian orogeny which occurred between 375 and 359 million years ago.[28] The Acadian orogeny was caused by a series of collisions of pieces of crust from the Avalonia Terrane, sections broken off from continent of Gondwana, with the North American Plate. The collision initiating this orogeny resulted in the closing of the southern Iapetus Ocean and the formation of a high mountain belt. After the Acadian collision took place, Gondwana began to retreat from Laurentia with the newly accretedAvalonianterranes left behind. As Gondwana moved away, a new ocean opened up, the Rheic Ocean, during the Middle to Late Devonian, and subsequently its closure would result in the formation of the Alleghanian orogeny.
Alleghenian Orogeny and Supercontinent Pangea
As the continental plates moved closer together, fragments of oceanic crust, islands, and other continental masses collided with the eastern margin of ancestral North America. By this time, plants had appeared on land, followed by scorpions, insects, and amphibians. The ocean continued to shrink until, about 270 million years ago, the continents that were ancestral to North America and Africa collided during the formation of the supercontinent Pangea.[26]
By the end of the Mesozoic Era, the Appalachian Mountains had been eroded to an almost flat plain.[27] It was not until the region was uplifted during the Cenozoic Era that the distinctive topography of the present formed.[29] Uplift rejuvenated the streams, which rapidly responded by cutting downward into the ancient bedrock. Some streams flowed along weak layers that define the folds and faults created many millions of years earlier. Other streams downcut so rapidly that they cut right across the resistant folded rocks of the mountain core, carving canyons across rock layers and geologic structures.
The 1859 discovery of commercial quantities of petroleum in the Appalachian Mountains of western Pennsylvania started the modern United States petroleum industry.[33] Recent discoveries of commercial natural gas deposits in the Marcellus Shale formation and Utica Shale formations have once again focused oil industry attention on the Appalachian Basin.
Some plateaus of the Appalachian Mountains contain metallic minerals such as iron and zinc.[34]
Drainage
Paleogeographic reconstruction showing the Appalachian Basin area during the Middle Devonian period
There are many geological issues concerning the rivers and streams of the Appalachians. In spite of the existence of the Great Appalachian Valley, many of the main rivers are transverse to the mountain system axis. The drainage divide of the Appalachians follows a tortuous course that crosses the mountainous belt just north of the New River in Virginia. South of the New River, rivers head into the Blue Ridge, cross the higher Unakas, receive important tributaries from the Great Valley, and traversing the Cumberland Plateau in spreading gorges (water gaps), escape by way of the Cumberland River and the Tennessee River rivers to the Ohio River and the Mississippi River, and thence to the Gulf of Mexico. In the central section, north of the New River, the rivers, rising in or just beyond the Valley Ridges, flow through great gorges to the Great Valley, and then across the Blue Ridge to tidal estuaries penetrating the coastal plain via the Roanoke River, James River, Potomac River, and Susquehanna River.[19]
In the northern section the height of land lies on the inland side of the mountainous belt, and thus the main lines of drainage run from north to south, exemplified by the Hudson River.[19] However, the valley through which the Hudson River flows was cut by the gigantic glaciers of the ice ages—the same glaciers that deposited their terminal moraines in southern New York and formed the east–west Long Island.
The Appalachian region is generally considered the geographical divide between the eastern seaboard of the United States and the Midwest region of the country. The Eastern Continental Divide follows the Appalachian Mountains from Pennsylvania to Georgia.
Ecology
The Appalachians, particularly the Central and Southern regions, is one of the most biodiverse places in North America.[36] The north–south orientation of the long ridges and valleys contributes to the high number of plant and animal species. Species were able to migrate through these from either direction during alternating periods of warming and cooling, settling in the microclimates that best suited them.[37]
The flora of the Appalachians are diverse and vary primarily in response to geology, latitude, elevation and moisture availability. Geobotanically, they constitute a floristic province of the North American Atlantic Region. The Appalachians consist primarily of deciduous broad-leaf trees and evergreen needle-leaf conifers, but also contain the evergreen broad-leaf American holly (Ilex opaca), and the deciduous needle-leaf conifer, the tamarack, or eastern larch (Larix laricina).
The dominant northern and high elevation conifer is the red spruce (Picea rubens), which grows from near sea level to above 4,000ft (1,200m)above sea level (asl) in northern New England and southeastern Canada. It also grows southward along the Appalachian crest to the highest elevations of the southern Appalachians, as in North Carolina and Tennessee. In the central Appalachians it is usually confined above 3,000ft (900m) asl, except for a few cold valleys in which it reaches lower elevations. In the southern Appalachians, it is restricted to higher elevations. Another species is the black spruce (Picea mariana), which extends farthest north of any conifer in North America, is found at high elevations in the northern Appalachians, and in bogs as far south as Pennsylvania.
The Appalachians are also home to two species of fir, the boreal balsam fir (Abies balsamea), and the southern high elevation endemic, Fraser fir (Abies fraseri). Fraser fir is endemic to the highest parts of the southern Appalachian Mountains, where along with red spruce it forms a fragile ecosystem known as the Southern Appalachian spruce–fir forest. Fraser fir rarely occurs below 5,500ft (1,700m), and becomes the dominant tree type at 6,200ft (1,900m).[38] By contrast, balsam fir is found from near sea level to the tree line in the northern Appalachians, but ranges only as far south as Virginia and West Virginia in the central Appalachians, where it is usually confined above 3,900ft (1,200m) asl, except in cold valleys. Curiously, it is associated with oaks in Virginia. The balsam fir of Virginia and West Virginia is thought by some to be a natural hybrid between the more northern variety and Fraser fir. While red spruce is common in both upland and bog habitats, balsam fir, as well as black spruce and tamarack, are more characteristic of the latter. However, balsam fir also does well in soils with a pH as high as 6.[39]
Eastern or Canada hemlock (Tsuga canadensis) is another important evergreen needle-leaf conifer that grows along the Appalachian chain from north to south but is confined to lower elevations than red spruce and the firs. It generally occupies richer and less acidic soils than the spruce and firs and is characteristic of deep, shaded and moist mountain valleys and coves. It is subject to the hemlock woolly adelgid (Adelges tsugae), an introduced insect, that is rapidly extirpating it as a forest tree. Less abundant, and restricted to the southern Appalachians, is Carolina hemlock (Tsuga caroliniana). Like Canada hemlock, this tree suffers severely from the hemlock woolly adelgid.
Several species of pines characteristic of the Appalachians are eastern white pine (Pinus strobus), Virginia pine (Pinus virginiana), pitch pine (Pinus rigida), Table Mountain pine (Pinus pungens) and shortleaf pine (Pinus echinata). Red pine (Pinus resinosa) is a boreal species that forms a few high elevation outliers as far south as West Virginia. All of these species except white pine tend to occupy sandy, rocky, poor soil sites, which are mostly acidic in character. White pine, a large species valued for its timber, tends to do best in rich, moist soil, either acidic or alkaline in character. Pitch pine is also at home in acidic, boggy soil, and Table Mountain pine may occasionally be found in this habitat as well. Shortleaf pine is generally found in warmer habitats and at lower elevations than the other species. All the species listed do best in open or lightly shaded habitats, although white pine also thrives in shady coves, valleys, and on floodplains.
The Appalachians are characterized by a wealth of large, beautiful deciduous broadleaf (hardwood) trees. Their occurrences are best summarized and described in E. Lucy Braun's 1950 classic, Deciduous Forests of Eastern North America (Macmillan, New York). The most diverse and richest forests are the mixed-mesophytic or medium-moisture types, which are largely confined to rich, moist montane soils of the southern and central Appalachians, particularly in the Cumberland and Allegheny Mountains, but also thrive in the southern Appalachian coves. Characteristic canopy species are white basswood (Tilia heterophylla), yellow buckeye (Aesculus octandra), sugar maple (Acer saccharum), American beech (Fagus grandifolia), tuliptree (Liriodendron tulipifera), white ash (Fraxinus americana) and yellow birch (Betula alleganiensis). Other common trees are red maple (Acer rubrum), shagbark and bitternut hickories (Carya ovata and C. cordiformis) and black or sweet birch (Betula lenta). Small understory trees and shrubs include paw paw (Asimina tribola), flowering dogwood (Cornus florida), hophornbeam (Ostrya virginiana), witch-hazel (Hamamelis virginiana) and spicebush (Lindera benzoin). There are also hundreds of perennial and annual herbs, among them such herbal and medicinal plants as American ginseng (Panax quinquefolius), goldenseal (Hydrastis canadensis), bloodroot (Sanguinaria canadensis) and black cohosh (Cimicifuga racemosa).
The foregoing trees, shrubs, and herbs are also more widely distributed in less rich mesic forests that generally occupy coves, stream valleys and flood plains throughout the southern and central Appalachians at low and intermediate elevations. In the northern Appalachians and at higher elevations of the central and southern Appalachians these diverse mesic forests give way to less diverse northern hardwood forests with canopies dominated only by American beech, sugar maple, American basswood (Tilia americana) and yellow birch and with far fewer species of shrubs and herbs.
Drier and rockier uplands and ridges are occupied by oak–chestnut forests dominated by a variety of oaks (Quercus spp.), hickories (Carya spp.) and, in the past, by the American chestnut (Castanea dentata). The American chestnut was virtually eliminated as a canopy species by the introduced fungal chestnut blight (Cryphonectaria parasitica), but lives on as sapling-sized sprouts that originate from roots, which are not killed by the fungus. In present-day forest canopies, chestnut has been largely replaced by oaks.
The oak forests of the southern and central Appalachians consist largely of black, northern red, white, chestnut and scarlet oaks (Quercus velutina, Q. rubra, Q. alba, Q. prinus and Q. coccinea) and hickories, such as the pignut (Carya glabra) in particular. The richest forests, which grade into mesic types, usually in coves and on gentle slopes, have predominantly white and northern red oaks, while the driest sites are dominated by chestnut oak, or sometimes by scarlet or northern red oaks. In the northern Appalachians the oaks, except for white and northern red, drop out, while the latter extends farthest north.
The oak forests generally lack the diverse small tree, shrub and herb layers of mesic forests. Shrubs are generally ericaceous, and include the evergreen mountain laurel (Kalmia latifolia), various species of blueberries (Vaccinium spp.), black huckleberry (Gaylussacia baccata), a number of deciduous rhododendrons (azaleas), and smaller heaths such as teaberry (Gaultheria procumbens) and trailing arbutus (Epigaea repens). The evergreen great rhododendron (Rhododendron maximum) is characteristic of moist stream valleys. These occurrences are in line with the prevailing acidic character of most oak forest soils. In contrast, the much rarer chinquapin oak (Quercus muehlenbergii) demands alkaline soils and generally grows where limestone rock is near the surface. Hence no ericaceous shrubs are associated with it.
The Appalachian flora also include a diverse assemblage of bryophytes (mosses and liverworts), as well as fungi. Some species are rare and/or endemic. As with vascular plants, these tend to be closely related to the character of the soils and the thermal environment in which they are found.
Eastern deciduous forests are subject to a number of serious insect and disease outbreaks. Among the most conspicuous is that of the introduced spongy moth (Lymantria dispar), which infests primarily oaks, causing severe defoliation and tree mortality. But it also has the benefit of eliminating weak individuals, and thus improving the genetic stock, as well as creating rich habitat of a type through accumulation of dead wood. Because hardwoods sprout so readily, this moth is not as harmful as the hemlock woolly adelgid. Perhaps more serious is the introduced beech bark disease complex, which includes both a scale insect (Cryptococcus fagisuga) and fungal components.
During the 19th and early 20th centuries, the Appalachian forests were subject to severe and destructive logging and land clearing, which resulted in the designation of the national forests and parks as well many state-protected areas. However, these and a variety of other destructive activities continue, albeit in diminished forms; and thus far only a few ecologically based management practices have taken hold.
Several mountain summits in the southern Appalachians are covered with expansive open habitats (either grassy meadows or heath) known as Appalachian balds. These habitats support many unique plant and animal communities, including rare, relict species, that are adapted to the open, exposed habitat. Their origins are heavily debated; while all were formerly thought to have anthropogenic origins, more recent evidence indicates a mixed origin: many were formed by climatic conditions in the Pleistocene and kept open by Pleistocene megafauna, then by other grazing wildlife (such as bison, elk, and deer) and Native American burning practices, and finally by grazing livestock introduced by European settlers. Others, especially those dominated by introduced grasses, may be fully anthropogenic in origin. The abandonment of grazing has caused trees to encroach on many of these balds, threatening their ecosystems.[43][44]
In contrast to the largely grazing-influenced balds of the southern Appalachians, parts of the northern Appalachians such as the White Mountains. the Adirondack Mountains, and Mount Katahdin have summits covered with true alpine tundra; these ecosystems are kept clear due to extremely harsh winter storms, and support a vegetation community more akin to that of the Arctic Circle.[45][46][47]
Animals that characterize the Appalachian forests include five species of tree squirrels. The most commonly seen is the low to moderate elevation eastern gray squirrel (Sciurus carolinensis). Occupying similar habitat is the slightly larger fox squirrel (Sciurus niger) and the much smaller southern flying squirrel (Glaucomys volans). More characteristic of cooler northern and high elevation habitat is the red squirrel (Tamiasciurus hudsonicus), whereas the Appalachian northern flying squirrel (Glaucomys sabrinus fuscus), which closely resembles the southern flying squirrel, is confined to northern hardwood and spruce–fir forests.
As familiar as squirrels are the eastern cottontail rabbit (Silvilagus floridanus) and the white-tailed deer (Odocoileus virginianus). The latter in particular has greatly increased in abundance as a result of the extirpation of the eastern wolf (Canis lupus lycaon) and the North American cougar. This has led to the overgrazing and browsing of many plants of the Appalachian forests, as well as destruction of agricultural crops. Other deer include the moose (Alces alces), found only in the north, and the elk (Cervus canadensis), which, although once extirpated, is now making a comeback, through transplantation, in the southern and central Appalachians. In Quebec, the Chic-Chocs host the only population of reindeer (Rangifer tarandus) south of the St. Lawrence River. An additional species that is common in the north but extends its range southward at high elevations to Virginia and West Virginia is the varying or snowshoe hare (Lepus americanus). However, these central Appalachian populations are scattered and very small.
Another species of great interest is the beaver (Castor canadensis), which is showing a great resurgence in numbers after its near extirpation for its pelt. This resurgence is bringing about a drastic alteration in habitat through the construction of dams and other structures throughout the mountains.
Other common forest animals are the black bear (Ursus americanus), striped skunk (Mephitis mephitis), raccoon (Procyon lotor), opossum (Didelphis virginianus), woodchuck (Marmota monax), bobcat (Lynx rufus), gray fox (Urocyon cinereoargenteus), red fox (Vulpes vulpes) and in recent years, the coyote (Canis latrans), another species favored by the advent of Europeans and the extirpation of eastern and red wolves (Canis rufus). European boars (Sus scrofa) were introduced in the early 20th century.
Of great importance are the many species of salamanders and, in particular, the lungless species (Family Plethodontidae) that live in great abundance concealed by leaves and debris, on the forest floor. Most frequently seen, however, is the eastern or red-spotted newt (Notophthalmus viridescens), whose terrestrial eft form is often encountered on the open, dry forest floor. It has been estimated that salamanders represent the largest class of animal biomass in the Appalachian forests. Frogs and toads are of lesser diversity and abundance, but the wood frog (Rana sylvatica) is, like the eft, commonly encountered on the dry forest floor, while a number of species of small frogs, such as spring peepers (Pseudacris crucifer), enliven the forest with their calls. Salamanders and other amphibians contribute greatly to nutrient cycling through their consumption of small life forms on the forest floor and in aquatic habitats.
Although reptiles are less abundant and diverse than amphibians, a number of snakes are conspicuous members of the fauna. One of the largest is the non-venomous black rat snake (Elaphe obsoleta obsoleta), while the common garter snake (Thamnophis sirtalis) is among the smallest but most abundant. The Eastern copperhead (Agkistrodon contortrix) and the timber rattler (Crotalus horridus) are venomous pit vipers. There are few lizards, but the broad-headed skink (Eumeces laticeps), at up to 13in (33cm) in length, and an excellent climber and swimmer, is one of the largest and most spectacular in appearance and action. The most common turtle is the eastern box turtle (Terrapene carolina carolina), which is found in both upland and lowland forests in the central and southern Appalachians. Prominent among aquatic species is the large common snapping turtle (Chelydra serpentina), which occurs throughout the Appalachians.
Appalachian streams are notable for their highly diverse freshwater fish life. Among the most abundant and diverse are those of the minnow family (family Cyprinidae), while species of the colorful darters (Percina spp.) are also abundant.[48]
A characteristic fish of shaded, cool Appalachian forest streams is the wild brook or speckled trout (Salvelinus fontinalis), which is much sought after as a game fish.[49][50]
Impact on North American history
Indigenous people
The roots of the Appalachian regions' histories trace back to the indigenous peoples who inhabited these lands long before European arrival. Indigenous communities across the Appalachians developed diverse cultures, languages, and societies, adapting to the region's varying environments and ecosystems. The interactions between indigenous communities and the natural world laid the foundation for the intricate relationship between humans and the Appalachian landscape.[51] Indigenous peoples thrived in these challenging terrains, adapting their lifestyles to the resources available. They forged deep connections with the land, developing sustainable practices for hunting, fishing, agriculture, and gathering. The Appalachian landscape provided a rich tapestry of flora and fauna, which indigenous communities learned to harness for their sustenance and well-being.[52] The Appalachian Mountains served as a conduit for trade networks, connecting distant indigenous communities through intricate trails. These trade routes facilitated the exchange of goods, ideas, and cultural practices across vast distances. This network fostered a sense of shared identity among diverse indigenous groups, transcending geographical boundaries.[53]
European exploration
During the late 15th and early 16th centuries, European explorers embarked on voyages of discovery across the Atlantic Ocean. While seeking new trade routes and riches, they encountered the vast landmass of North America, including the Appalachian regions. The mountains posed a formidable geographical obstacle that European explorers had to navigate. The French, British, and Spanish were among the major powers vying for dominance in the New World, and their interactions with indigenous communities and the Appalachian landscape shaped the course of history.
Colonial settlements
The Appalachian Highlands and Lowlands became focal points for European colonial expansion. French and British explorers traversed the Appalachian Mountains as they established footholds in North America. The French established settlements in the Great Lakes region and Canada, while the British colonies stretched along the eastern seaboard of what would become the United States. The territorial ambitions of European powers set the stage for later conflicts such as the French and Indian War.
The British Proclamation of 1763 holds significance in both Canadian and American histories. In the United States, the proclamation aimed to curb westward expansion beyond the Appalachian Mountains to avoid conflicts with indigenous nations, leading to tensions between American colonists and the British Crown and contributing to the drive for independence. In Canada, the proclamation provided a framework for governing newly acquired French territories, including Quebec, to ensure stability and control over the region. The ramifications of the proclamation were multifaceted, reflecting the complex dynamics of colonial governance and indigenous relations.
Cultural exchange and identity
The Appalachian Mountains in both countries nurtured unique cultural identities that persist to this day. The isolation of these mountainous regions allowed for the development of distinctive music, folklore, and traditions. Appalachian music played a significant role in the broader evolution of American and Canadian music genres. While each side of the border has its own cultural expressions, the shared geographical features and historical interactions contributed to common threads of self-reliance, resilience, and connection to nature that characterize Appalachian culture.
Colonization and frontier expansion
European exploration of the Appalachian regions contributed to the mapping and understanding of the area's geographical features. Explorers documented the rugged terrain, dense forests, and abundant natural resources. Their observations shaped the perceptions of the Appalachian landscape and influenced subsequent settlement patterns and resource utilization. The range posed significant barriers to westward expansion, leaving an indelible mark on colonization efforts.
Cumberland Gap and Gaspé Peninsula
The Cumberland Gap, a prominent geographic feature, played a pivotal role in westward expansion in the United States. This passage through the Appalachian Mountains provided a route for pioneers seeking new opportunities beyond the mountains. Similarly, Canada had its own geographical passage, the Gaspé Peninsula, which facilitated exploration and trade in the Canadian Appalachian region. These passages were vital gateways that shaped the movement of people, ideas, and resources on both sides of the border. "Gaspé Peninsula". The Canadian Encyclopedia.
1 2 France maintains governmental control of eight small islands off the southern coast of Newfoundland, Canada, named Saint Pierre and Miquelon. Newfoundland is generally considered the northernmost point of the Appalachian range. Therefore, the Appalachians run through the lone remaining North American territory of France.
↑ measured from Montgomery, Alabama which is at the southwestern end of the Coosa Valley, to Belle Island, Newfoundland and Labrador which is the northeastern-most extent of Newfoundland
↑ Many internet sources cite 480 million years as the age of the Appalachians. This statement ignores some of the highest and most prominent features of the range that exposes scientifically-dated metamorphic rocks that are at least 1 billion years old.
↑ Originally the intent was that there would be two sections, the Champlain and the Northern section, however the dividing line was never officially determined
↑ Description used by 1911 Encyclopedia Britannica that is now in the public domain
Related Research Articles
The Piedmont is a plateau region located in the Eastern United States. It is situated between the Atlantic Plain and the Blue Ridge Mountains, stretching from New York in the north to central Alabama in the south. The Piedmont Province is a physiographic province of the larger Appalachian Highlands physiographic division and consists of the Piedmont Upland, and the Piedmont Lowlands sections.
The Blue Ridge Mountains are a physiographic province of the larger Appalachian Highlands range. The mountain range is located in the Eastern United States and extends 550 miles southwest from southern Pennsylvania through Maryland, West Virginia, Virginia, North Carolina, South Carolina, Tennessee, and Georgia. The province consists of northern and southern physiographic regions, which divide near the Roanoke River gap. To the west of the Blue Ridge, between it and the bulk of the Appalachians, lies the Great Appalachian Valley, bordered on the west by the Ridge and Valley province of the Appalachian range.
The Allegheny Mountain Range, informally the Alleghenies, is part of the vast Appalachian Mountain Range of the Eastern United States and Canada and posed a significant barrier to land travel in less developed eras. The Allegheny Mountains have a northeast–southwest orientation, running for about 300 miles (480 km) from north-central Pennsylvania southward, through western Maryland and eastern West Virginia.
The Cumberland Plateau is the southern part of the Appalachian Plateau in the Appalachian Mountains of the United States. It includes much of eastern Kentucky and Tennessee, and portions of northern Alabama and northwest Georgia. The terms "Allegheny Plateau" and the "Cumberland Plateau" both refer to the dissected plateau lands lying west of the main Appalachian Mountains. The terms stem from historical usage rather than geological difference, so there is no strict dividing line between the two. Two major rivers share the names of the plateaus, with the Allegheny River rising in the Allegheny Plateau and the Cumberland River rising in the Cumberland Plateau in Harlan County, Kentucky.
The Allegheny Plateau is a large dissected plateau area of the Appalachian Mountains in western and central New York, northern and western Pennsylvania, northern and western West Virginia, and eastern Ohio. It is divided into the unglaciated Allegheny Plateau and the glaciated Allegheny Plateau.
The Ridge-and-Valley Appalachians, also called the Ridge and Valley Province or the Valley and Ridge Appalachians, are a physiographic province of the larger Appalachian Highlands division. The physiographic province is divided into three sections: the Hudson Valley, the Central, and the Tennessee.
The Cumberland Mountains are a mountain range in the southeastern section of the Appalachian Mountains. They are located in western Virginia, southwestern West Virginia, the eastern edges of Kentucky, and eastern middle Tennessee, including the Crab Orchard Mountains. Their highest peak, with an elevation of 4,223 feet (1,287 m) above mean sea level, is High Knob, which is located near Norton, Virginia.
The Allegheny Front is the major southeast- or east-facing escarpment in the Allegheny Mountains in southern Pennsylvania, western Maryland, eastern West Virginia, and western Virginia. The Allegheny Front forms the boundary between the Ridge-and-Valley Appalachians to its east and the Appalachian Plateau to its west. The Front is closely associated with the Appalachian Mountains' Eastern Continental Divide, which in this area divides the waters of the Ohio/Mississippi river system, flowing to the Gulf of Mexico, from rivers flowing into Chesapeake Bay and from there into the Atlantic Ocean.
The Appalachian Plateau is a series of rugged dissected plateaus located on the western side of the Appalachian Mountains. The Appalachian Mountains are a range that run from Nova Scotia in Canada to Alabama in the United States.
The environment of West Virginia encompasses terrain and ecosystems ranging from plateaus to mountains. Most of West Virginia lies within the Appalachian mixed mesophytic forests ecoregion, while the higher elevations along the eastern border and in the panhandle lie within the Appalachian-Blue Ridge forests.
The Black Mountains are a mountain range in western North Carolina, in the southeastern United States. They are part of the Blue Ridge Province of the Southern Appalachian Mountains. The Black Mountains are the highest mountains in the Eastern United States. The range takes its name from the dark appearance of the red spruce and Fraser fir trees that form a spruce-fir forest on the upper slopes which contrasts with the brown or lighter green appearance of the deciduous trees at lower elevations. The Eastern Continental Divide, which runs along the eastern Blue Ridge crest, intersects the southern tip of the Black Mountain range.
The Appalachian mixed mesophytic forests is an ecoregion of the temperate broadleaf and mixed forests biome, as defined by the World Wildlife Fund. It consists of mesophytic plants west of the Appalachian Mountains in the Southeastern United States.
The Appalachian–Blue Ridge forests are an ecoregion in the Temperate broadleaf and mixed forests Biome, in the Eastern United States. The ecoregion is located in the central and southern Appalachian Mountains, including the Ridge-and-Valley Appalachians and the Blue Ridge Mountains. It covers an area of about 61,500 square miles (159,000 km2) in: northeast Alabama and Georgia, northwest South Carolina, eastern Tennessee, western North Carolina, Virginia, Maryland, and central West Virginia and Pennsylvania; and small extensions into Kentucky, New Jersey, and New York.
The Appalachian Highlands is one of eight government-defined physiographic divisions of the contiguous United States. It links with the Appalachian Uplands in Canada to make up the Appalachian Mountains. The Highlands includes seven physiographic provinces, which is the second level in the physiographic classification system in the United States. At the next level of physiographic classification, called section/subsection, there are 20 unique land areas with one of the provinces having no sections.
The Geology of Pennsylvania consists of six distinct physiographic provinces, three of which are subdivided into different sections. Each province has its own economic advantages and geologic hazards and plays an important role in shaping everyday life in the state. From the southeast corner to the northwest corner of the state, they include: the Atlantic Plain Province, the Piedmont Province, the New England Province, the Ridge and Valley Province, the Appalachain Province, and the Central Lowlands Province.
In the central and southern Appalachian Mountains of Eastern North America, a cove is a small valley between two ridge lines that is closed at one or both ends.
The U.S. state of Tennessee is geographically diverse, with varying terrains and several distinct physiographic regions. Its landforms range from the Blue Ridge Mountains in the eastern part of the state to flat and fertile plains along the Mississippi River. The state is geographically, legally, culturally, and economically divided into three Grand Divisions: East Tennessee, Middle Tennessee, and West Tennessee.
Spruce Mountain, located in eastern West Virginia, is the highest ridge of the Allegheny Mountains. The whale-backed ridge extends for only 16 miles (26 km) from northeast to southwest, but several of its peaks exceed 4,500 feet (1,400 m) in elevation. The summit, Spruce Knob, is the highest Allegheny Mountain point both in the state and the entire range, which spans four states.
The Northeastern Highlands Ecoregion is a Level III ecoregion designated by the United States Environmental Protection Agency (EPA) in the U.S. states of Vermont, New Hampshire, Massachusetts, Maine, Connecticut, New York, New Jersey, and Pennsylvania. The ecoregion extends from the northern tip of Maine and runs south along the Appalachian Mountain Range into eastern Pennsylvania. Discontiguous sections are located among New York's Adirondack Mountains, Catskill Range, and Tug Hill. The largest portion of the Northeastern Highlands ecoregion includes several sub mountain ranges, including the Berkshires, Green Mountains, Taconic, and White Mountains.
References
↑ "Saint Pierre and Miquelon". World Factbook. Retrieved August 15, 2023. the islands are actually part of the northern Appalachians along with Newfoundland
1 2 3 Thomas, William A.; Hatcher, Jr., Robert D. (2021). "Southern-Central Appalachians-Ouachitas Orogen". Encyclopedia of Geology. 4– via Elsevier Science Direct. The foundations of the Appalachian-Ouachita orogen were laid when the assembly of supercontinent Rodinia was completed. The collisional events were accompanied by high-grade metamorphism and magmatism during the Grenville orogeny in the time span of 1300–950 Ma.
↑ "Saint Pierre and Miquelon". World Factbook. Retrieved August 15, 2023. the islands are actually part of the northern Appalachians along with Newfoundland
↑ Clark, Sandra H. B. (1996). Birth of the Mountains: The Geologic Story of the Southern Appalachian Mountains(PDF). United States Geologic Survey. p.4. The rocks at the core of the Appalachian Mountains formed more than a billion years ago. At that time, all of the continents were joined together in a single supercontinent surrounded by a single ocean. Remnants of the supercontinent make up much of the North American core and are composed of minerals that are more than a billion years old.
↑ Brown, Daniel. "Cumberland Gap: A new beginning". National Park Service. To the English settlers of North America the Appalachian Mountains formed an almost impenetrable geographic barrier.
↑ Keppie, J. D. (2006). "Avalonian terranes of the Appalachian orogen: A review". Geological Society of America Bulletin. 129 (9/10): 1195–1208. doi:10.1130/B31595.1.
↑ Rankin, James W. (1993). The volcanogenic Mount Rogers Formation and the overlying glaciogenic Konnarock Formation: Two late Proterozoic units in southwestern Virginia. USGS. doi:10.3133/b2029.
↑ Kaygi, Patti Boyd (1994). The Fries Fault near Riner, Virginia: an example of a polydeformed, ductile deformation zone. VT Works.
↑ Hatch, N. L. (2009). "The Acadian orogeny: A review". Geological Society of America Bulletin. 121 (5–6): 639–678.
↑ Poag, C. Wylie; Sevon, William D. (September 1989). "A record of Appalachian denudation in postrift Mesozoic and Cenozoic sedimentary deposits of the U.S. Middle Atlantic continental margin". Geomorphology. 2 (1–3): 119–157. Bibcode:1989Geomo...2..119P. doi:10.1016/0169-555X(89)90009-3.
↑ Elliston, Jon (October 31, 2019). "Heart of Appalachia". No.Winter 2019. The Nature Conservancy. The Nature Conservancy. Retrieved June 16, 2020.
↑ Jeffries, Stephanie B; Wentworth, Thomas R. (2014). Exploring Southern Appalachian Forests (1ed.). Chapel Hill NC: The University of North Carolina Press. p.8. ISBN9781469619798.
↑ Rose Houk, Great Smoky Mountains National Park: A Natural History Guide (Boston: Houghton-Mifflin, 1993), pp. 50–62.
↑ Fowells, H.A., 1965, Silvics of Forest Trees of the United States, Agricultural Handbook No. 271, United States Department of Agriculture, Forest Service, Washington, D.C.
Constantz, George (2004), Hollows, Peepers, and Highlanders: an Appalachian Mountain Ecology (2nd edition). West Virginia University Press; Morgantown. 359 p.
Olson, Ted (1998), Blue Ridge Folklife. University Press of Mississippi, 211 pages, ISBN1-57806-023-0.
Rehder, John (2013) "Appalachian Folkways", Koxville: University of Tennessee Press.
Chapters iii., iv. and v. of Miss E. C. Semple's American History and its Geographic Conditions (Boston, 1903).
Weidensaul, Scott (2000), Mountains of the Heart: A Natural History of the Appalachians. Fulcrum Publishing, 288 pages, ISBN1-55591-139-0.
Bailey Willis, The Northern Appalachians, and C. W. Hayes, The Southern Appalachians, both in National Geographic Monographs, vol. 9.
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