The range is older than the other major mountain range in North America, theRocky Mountains of the west. Some of theoutcrops in the Appalachians contain rocks formed during thePrecambrian 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 ofLaurentia andAmazonia collided, creating a supercontinent calledRodinia. 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 theAlps 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 ofalternating ridgelines and valleys oriented in opposition to mosthighways andrailroads running east–west. This barrier was extremely important in shaping the expansion of the United States in the colonial era.[10]
While exploring inland along the northern coast ofFlorida in 1528, the members of theNarváez expedition, includingÁlvar Núñez Cabeza de Vaca, found aNative American village near present-dayTallahassee, Florida, whose name they transcribed asApalchen orApalachenApalachee pronunciation:[a.paˈla.tʃɛn]. The name was soon altered by the Spanish toApalachee 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 ofHernando de Soto, Spanish cartographers began to apply the name of the tribe to the mountains themselves. The first cartographic appearance ofApalchen is onDiego Gutiérrez's map of 1562; the first use for the mountain range is the map ofJacques le Moyne de Morgues in 1565.[12]
Diego Gutiérrez's 1562 map of theWestern 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 most regions of the Appalachians, the word is pronounced/ˌæpəˈlætʃɪnz/, with the third syllable sounding like "latch". In some northern parts of the mountain range, particularly Pennsylvania, 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 adjectiveAppalachian is/ˌæpəˈlætʃiən/, with the last two syllables "-ian" pronounced as in the word "Romanian".[15]
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 termedthe 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 majorlandforms that make up the countries, theUnited States Geological Survey (USGS) and theGeological Survey of Canada (GSC). The landforms are referred to asphysiographic regions. The regions create precise boundaries from which maps can be drawn. The Appalachian Highlands is the name of one of the eightphysiographic regions of the contiguous 48 United States.[16]The Appalachian Uplands is the name of one of seven physiographic regions of Canada.[17]
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 inCanada. 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]
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, theSt. 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 beenglaciated, 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 theAtlantic Ocean inNew England, and southeastward to the border of thecoastal 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 theGreat 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]
InPennsylvania, there are over sixty summits that rise over 2,500 ft (800 m); the summits ofMount Davis andBlue Knob rise over 3,000 ft (900 m). In Maryland, Eagle Rock andDans Mountain are conspicuous points reaching 3,162 and 2,882 ft (964 and 878 m) respectively. On the same side of the Great Valley, south of the Potomac, are the Pinnacle 3,007 feet (917 m) and Pidgeon Roost 3,400 ft (1,000 m).[19] In West Virginia, more than 150 peaks rise above 4,000 ft (1,200 m), includingSpruce Knob 4,863 ft (1,482 m), the highest point in theAllegheny Mountains. A number of other points in the state rise above 4,800 ft (1,500 m).Cheat Mountain (Snowshoe Mountain) at Thorny Flat 4,848 ft (1,478 m) andBald Knob 4,842 ft (1,476 m) are among the more notable peaks in West Virginia.
TheBlue Ridge Mountains, rising in southern Pennsylvania and there known asSouth Mountain, attain elevations of about 2,000 ft (600 m) in Pennsylvania. South Mountain achieves its highest point just below theMason-Dixon line inMaryland atQuirauk Mountain 2,145 ft (654 m) and then diminishes in height southward to thePotomac River. Once inVirginia, the Blue Ridge again reaches 2,000 ft (600 m) and higher. In the Virginia Blue Ridge, the following are some of the highest peaks north of theRoanoke River: Stony Man 4,031 ft (1,229 m),Hawksbill Mountain 4,066 ft (1,239 m),Apple Orchard Mountain 4,225 ft (1,288 m) andPeaks of Otter 4,001 and 3,875 ft (1,220 and 1,181 m). South of the Roanoke River, along the Blue Ridge, are Virginia's highest peaks includingWhitetop Mountain 5,520 ft (1,680 m) andMount Rogers 5,729 ft (1,746 m), 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 theTennessee-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 theBlack Mountains,Great Craggy Mountains, andGreat Balsam Mountains, and its chief summits includeGrandfather Mountain 5,964 ft (1,818 m) near the Tennessee-North Carolina border,Mount Mitchell 6,684 ft (2,037 m) in the Blacks, andBlack Balsam Knob 6,214 ft (1,894 m) andCold Mountain 6,030 ft (1,840 m) in the Great Balsams. The Western Blue Ridge Front is subdivided into theUnaka Range, theBald Mountains, theGreat Smoky Mountains, and theUnicoi Mountains, and its major peaks includeRoan Mountain 6,285 ft (1,916 m) in the Unakas, Big Bald 5,516 ft (1,681 m) andMax Patch 4,616 ft (1,407 m) in the Bald Mountains,Kuwohi 6,643 ft (2,025 m),Mount Le Conte 6,593 feet (2,010 m), andMount Guyot 6,621 ft (2,018 m) in the Great Smokies, andBig Frog Mountain 4,224 ft (1,287 m) near the Tennessee-Georgia-North Carolina border. Prominent summits in the cross ridges includeWaterrock Knob (6,292 ft (1,918 m)) in thePlott Balsams. Across northern Georgia, numerous peaks exceed 4,000 ft (1,200 m), includingBrasstown Bald, the state's highest, at 4,784-and-4,696 ft (1,458-and-1,431 m)Rabun Bald. In north-centralAlabama,Mount Cheaha rises prominently to 1,445 feet (440 m) 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 Americancraton calledLaurentia collided with at least one other craton -Amazonia. All the other cratons of the earth also collided at about this time to form the supercontinentRodinia and were surrounded by one single ocean. (It is possible that the cratons ofKalahari, andRio Plato, were also part of that early collision since they were present as Rodinia broke up). Mountain-building referred to as theGrenville 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 - theBlue Ridge Mountains and theAdirondacks.
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 theIapetus 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, andPine 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]
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 middleOrdovician 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 theNorth American craton. Volcanoes grew along the continental margin coincident with the initiation ofsubduction. 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 (seeAlleghanian orogeny).[27]
The third mountain-building event was theAcadian 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 ofGondwana, with the North American Plate. The collision initiating this orogeny resulted in the closing of the southernIapetus Ocean and the formation of a high mountain belt. After the Acadian collision took place, Gondwana began to retreat from Laurentia with the newlyaccretedAvalonianterranes left behind. As Gondwana moved away, a new ocean opened up, theRheic Ocean, during the Middle to Late Devonian, and subsequently its closure would result in the formation of theAlleghanian orogeny.
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 thesupercontinent Pangea.[26]
By the end of theMesozoic Era, the Appalachian Mountains had been eroded to an almost flat plain.[27] It was not until the region was uplifted during theCenozoic Era that the distinctive topography of the present formed.[29] Upliftrejuvenated 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 streamsdowncut so rapidly that they cut right across the resistant folded rocks of the mountain core, carving canyons across rock layers and geologic structures.
The Appalachian Mountains contain major deposits ofanthracitecoal as well asbituminous coal. In the folded mountains the coal is in metamorphosed form asanthracite, represented by theCoal Region ofnortheastern Pennsylvania. The bituminous coal fields ofwestern Pennsylvania,western Maryland, southeastern Ohio, eastern Kentucky,southwestern Virginia, and West Virginia contain the sedimentary form of coal.[30] Themountain top removal method ofcoal mining, in which entire mountain tops are removed, is currently threatening vast areas and ecosystems of the Appalachian Mountain region.[31] The surface coal mining that started in the 1940s has significantly impacted the central Appalachian Mountains inKentucky,Tennessee, Virginia and West Virginia. Early mining methods were unregulated and mined land reclamation research, includingacid base reaction, was led by theWest Virginia University in the 1960s and 1970s. West Virginia developed rigorousmine reclamation standards for state coal mines in the late 1960s. Regulations were introduced by most states to protect the Appalachian Mountains by the late 1960s. Social and political activism brought about theSurface Mining Control and Reclamation Act of 1977.[32]
The1859 discovery of commercial quantities ofpetroleum in the Appalachian Mountains of western Pennsylvania started the modern United Statespetroleum industry.[33] Recent discoveries of commercialnatural gas deposits in theMarcellus Shale formation andUtica Shale formations have once again focused oil industry attention on the Appalachian Basin.
Some plateaus of the Appalachian Mountains contain metallic minerals such asiron andzinc.[34]
Paleogeographic reconstruction showing the Appalachian Basin area during the Middle Devonian period[35]
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. Thedrainage divide of the Appalachians follows a tortuous course that crosses the mountainous belt just north of theNew 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 theCumberland River and theTennessee River rivers to theOhio River and the Mississippi River, and thence to theGulf 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, andSusquehanna 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 theHudson River.[19] However, the valley through which the Hudson River flows was cut by the giganticglaciers of theice ages—the same glaciers that deposited theirterminal moraines in southern New York and formed the east–westLong Island.
The Appalachian region is generally considered the geographical divide between theeastern seaboard of the United States and theMidwest region of the country. TheEastern Continental Divide follows the Appalachian Mountains from Pennsylvania to Georgia.
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 afloristic province of theNorth American Atlantic Region. The Appalachians consist primarily of deciduous broad-leaf trees and evergreen needle-leaf conifers, but also contain the evergreen broad-leafAmerican holly (Ilex opaca), and the deciduous needle-leaf conifer, thetamarack, or eastern larch (Larix laricina).
The dominant northern and high elevation conifer is thered spruce (Picea rubens), which grows from near sea level to above 4,000 ft (1,200 m)above sea level (asl) in northernNew England and southeastern Canada. It also grows southward along the Appalachian crest to the highest elevations of the southern Appalachians, as inNorth Carolina andTennessee. In the central Appalachians it is usually confined above 3,000 ft (900 m) 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 theblack 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 borealbalsam fir (Abies balsamea), and the southern high elevation endemic,Fraser fir (Abies fraseri). Fraser fir isendemic to the highest parts of the southern Appalachian Mountains, where along with red spruce it forms a fragile ecosystem known as theSouthern Appalachian spruce–fir forest. Fraser fir rarely occurs below 5,500 ft (1,700 m), and becomes the dominant tree type at 6,200 ft (1,900 m).[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 3,900 ft (1,200 m) 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 andcoves. It is subject to thehemlock woolly adelgid (Adelges tsugae), an introduced insect, that is rapidly extirpating it as a forest tree. Less abundant, and restricted to the southern Appalachians, isCarolina hemlock (Tsuga caroliniana). Like Canada hemlock, this tree suffers severely from the hemlock woolly adelgid.
Several species of pines characteristic of the Appalachians areeastern white pine (Pinus strobus),Virginia pine (Pinus virginiana),pitch pine (Pinus rigida),Table Mountain pine (Pinus pungens) andshortleaf 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 inE. Lucy Braun's 1950 classic,Deciduous Forests of Eastern North America (Macmillan, New York). The most diverse and richest forests are themixed-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 arewhite basswood (Tilia heterophylla),yellow buckeye (Aesculus octandra),sugar maple (Acer saccharum),American beech (Fagus grandifolia),tuliptree (Liriodendron tulipifera),white ash (Fraxinus americana) andyellow birch (Betula alleganiensis). Other common trees arered maple (Acer rubrum),shagbark andbitternut hickories (Carya ovata andC. cordiformis) andblack or sweet birch (Betula lenta). Small understory trees and shrubs includepaw paw (Asimina tribola),flowering dogwood (Cornus florida),hophornbeam (Ostrya virginiana),witch-hazel (Hamamelis virginiana) andspicebush (Lindera benzoin). There are also hundreds of perennial and annual herbs, among them such herbal and medicinal plants as Americanginseng (Panax quinquefolius),goldenseal (Hydrastis canadensis),bloodroot (Sanguinaria canadensis) andblack cohosh (Cimicifuga racemosa).
The foregoing trees, shrubs, and herbs are also more widely distributed in less richmesic forests that generally occupy coves, stream valleys andflood 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 diversenorthern 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 byoak–chestnut forests dominated by a variety of oaks (Quercus spp.),hickories (Carya spp.) and, in the past, by theAmerican chestnut (Castanea dentata). The American chestnut was virtually eliminated as a canopy species by the introduced fungalchestnut 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.
Theoak forests of the southern and central Appalachians consist largely ofblack,northern red,white,chestnut andscarlet oaks (Quercus velutina,Q. rubra,Q. alba,Q. prinus andQ. 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 generallyericaceous, and include the evergreenmountain laurel (Kalmia latifolia), various species ofblueberries (Vaccinium spp.),black huckleberry (Gaylussacia baccata), a number of deciduousrhododendrons (azaleas), and smaller heaths such asteaberry (Gaultheria procumbens) andtrailing 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 rarerchinquapin 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 ofbryophytes (mosses and liverworts), as well asfungi. Some species are rare and/or endemic. As withvascular 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 introducedspongy 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 thehemlock woolly adelgid. Perhaps more serious is the introducedbeech 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 grassymeadows orheath) known asAppalachian 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 thePleistocene and kept open byPleistocene megafauna, then by other grazing wildlife (such asbison,elk, and deer) andNative American burning practices, and finally by grazinglivestock 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. theAdirondack Mountains, andMount Katahdin have summits covered with truealpine tundra; these ecosystems are kept clear due to extremely harsh winter storms, and support a vegetation community more akin to that of theArctic Circle.[45][46][47]
Animals that characterize the Appalachian forests include five species oftree squirrels. The most commonly seen is the low to moderate elevationeastern gray squirrel (Sciurus carolinensis). Occupying similar habitat is the slightly largerfox squirrel (Sciurus niger) and the much smallersouthern flying squirrel (Glaucomys volans). More characteristic of cooler northern and high elevation habitat is thered squirrel (Tamiasciurus hudsonicus), whereas the Appalachiannorthern 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 theeastern cottontail rabbit (Silvilagus floridanus) and thewhite-tailed deer (Odocoileus virginianus). The latter in particular has greatly increased in abundance as a result of the extirpation of theeastern wolf (Canis lupus lycaon) and theNorth American cougar. This has led to theovergrazing and browsing of many plants of the Appalachian forests, as well as destruction of agricultural crops. Other deer include themoose (Alces alces), found only in the north, and theelk (Cervus canadensis), which, although onceextirpated, is now making a comeback, through transplantation, in the southern and central Appalachians. InQuebec, the Chic-Chocs host the only population ofreindeer (Rangifer tarandus) south of theSt. 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 orsnowshoe hare (Lepus americanus). However, these central Appalachian populations are scattered and very small.
Another species of great interest is thebeaver (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 theblack 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, thecoyote (Canis latrans), another species favored by the advent of Europeans and the extirpation of eastern andred wolves (Canis rufus). Europeanboars (Sus scrofa) were introduced in the early 20th century.
Of great importance are the many species ofsalamanders and, in particular, thelungless species (family Plethodontidae) that live in great abundance concealed by leaves and debris, on the forest floor. Most frequently seen, however, is theeastern 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 thewood frog (Rana sylvatica) is, like the eft, commonly encountered on the dry forest floor, while a number of species of small frogs, such asspring 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-venomousblack rat snake (Elaphe obsoleta obsoleta), while thecommon garter snake (Thamnophis sirtalis) is among the smallest but most abundant. Theeastern copperhead (Agkistrodon contortrix) and thetimber rattler (Crotalus horridus) are venomouspit vipers. There are few lizards, but thebroad-headed skink (Eumeces laticeps), at up to 13 in (33 cm) 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 theeastern 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 largecommon 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 (familyCyprinidae), while species of the colorfuldarters (Percina spp.) are also abundant.[48]
A characteristic fish of shaded, cool Appalachian forest streams is thewild brook or speckled trout (Salvelinus fontinalis), which is much sought after as a game fish.[49][50]
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]
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.
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 theFrench and Indian War.
TheBritish 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.
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.
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.
TheCumberland 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, theGaspé 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.
^abFrance maintains governmental control of eight small islands off the southern coast of Newfoundland, Canada, namedSaint 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
^"Saint Pierre and Miquelon".World Factbook. RetrievedAugust 15, 2023.the islands are actually part of the northern Appalachians along with Newfoundland
^abcThomas, 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. RetrievedAugust 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. RetrievedJune 16, 2020.
^Jeffries, Stephanie B; Wentworth, Thomas R. (2014).Exploring Southern Appalachian Forests (1 ed.). 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'sAmerican 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 inNational Geographic Monographs, vol. 9.
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