Editing Appalachian Mountains (section)

==Ecology==
The Appalachians, particularly the Central and Southern regions, is one of the most biodiverse places in North America.<ref name="TNC">{{cite news |last1=Elliston |first1=Jon |title=Heart of Appalachia |url=https://www.nature.org/en-us/magazine/magazine-articles/cumberland-forest-project/ |access-date=June 16, 2020 |agency=The Nature Conservancy |issue=Winter 2019 |publisher=The Nature Conservancy |date=October 31, 2019}}</ref> 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.<ref name="Southern Getaways">{{cite book |last1=Jeffries |first1=Stephanie B |last2=Wentworth |first2=Thomas R. |title=Exploring Southern Appalachian Forests |date=2014 |publisher=The University of North Carolina Press |location=Chapel Hill NC |isbn=9781469619798 |page=8 |edition=1 }}</ref>

===Flora===
{{Further|Appalachian–Blue Ridge forests|Appalachian bogs|Appalachian mixed mesophytic forests|Appalachian temperate rainforest|New England/Acadian forests|List of plants endemic to the Appalachian Mountains}}
[[File:Mount Mitchell-27527.jpg|thumb|View from [[Mount Mitchell]], [[North Carolina]] at {{convert|6684|ft|m|abbr=on}}, the highest peak east of the [[Mississippi River]]]]
[[File:Rockytop and Patterson Ridges (13083210443).jpg|thumb|[[Shenandoah National Park]] in [[Virginia]]]]
[[File:Craggy Gardens-27527.jpg|thumb|View from Craggy Gardens on the [[Blue Ridge Parkway]] in [[North Carolina]]]]
[[File:Rhododendron maximum-27527.jpg|thumb|[[Rhododendron maximum|Great laurel]] thicket in the [[Pisgah National Forest]] in [[North Carolina]]]]
[[File:Cranberry-glades-fog-1.jpg|thumb|[[Cranberry Glades]], a bog preserve in [[West Virginia]]]]
[[File:HumpsRoan.jpg|thumb|Grassy balds on the [[Roan Mountain (Roan Highlands)|Roan Highlands]] straddling the [[North Carolina]]/[[Tennessee]] border]]
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 larch|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 {{convert|4000|ft|m|-2|abbr=on}} [[Above mean sea level|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 {{convert|3000|ft|m|-2|abbr=on}} 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 {{convert|5500|ft|m|-2|abbr=on}}, and becomes the dominant tree type at {{convert|6200|ft|m|-2|abbr=on}}.<ref>Rose Houk, ''Great Smoky Mountains National Park: A Natural History Guide'' (Boston: Houghton-Mifflin, 1993), pp. 50–62.</ref> 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 {{convert|3900|ft|m|-2|abbr=on}} 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.<ref>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.</ref>

[[Tsuga canadensis|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 [[cove (Appalachian Mountains)|cove]]s. 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 [[Emma Lucy Braun|E. Lucy Braun]]'s 1950 classic, ''Deciduous Forests of Eastern North America'' (Macmillan, New York). The most diverse and richest forests are the [[Appalachian mixed mesophytic forests|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 [[Tilia heterophylla|white basswood]] (''Tilia heterophylla''), [[yellow buckeye]] (''Aesculus octandra''), [[sugar maple]] (''Acer saccharum''), [[Fagus grandifolia|American beech]] (''Fagus grandifolia''), [[Liriodendron|tuliptree]] (''Liriodendron tulipifera''), [[Fraxinus americana|white ash]] (''Fraxinus americana'') and [[Betula alleghaniensis|yellow birch]] (''Betula alleganiensis''). Other common trees are [[Acer rubrum|red maple]] (''Acer rubrum''), [[Carya ovata|shagbark]] and [[Carya cordiformis|bitternut]] hickories (''Carya ovata'' and ''C. cordiformis'') and [[Betula lenta|black or sweet birch]] (''Betula lenta ''). Small understory trees and shrubs include [[Asimina triloba|paw paw]] (''Asimina tribola''), [[Cornus florida|flowering dogwood]] (''Cornus florida''), [[Ostrya|hophornbeam]] (''Ostrya virginiana''), [[witch-hazel]] (''Hamamelis virginiana'') and [[Lindera|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''), [[Sanguinaria|bloodroot]] (''Sanguinaria canadensis'') and [[Actaea racemosa|black cohosh]] (''Cimicifuga racemosa'').

The foregoing trees, shrubs, and herbs are also more widely distributed in less rich [[mesic habitat|mesic]] forests that generally occupy coves, stream valleys and [[flood plain]]s 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 [[Appalachian hemlock–northern hardwood forest|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 forest]]s dominated by a variety of oaks (''Quercus'' spp.), [[hickory|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 [[Central and southern Appalachian montane oak forest|oak forests of the southern and central Appalachians]] consist largely of [[Quercus velutina|black]], [[Northern red oak|northern red]], [[Quercus alba|white]], [[Chestnut oak|chestnut]] and [[scarlet oak]]s (''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 [[Calcifuge|ericaceous]], and include the evergreen [[Kalmia latifolia|mountain laurel]] (''Kalmia latifolia''), various species of [[blueberry|blueberries]] (''Vaccinium'' spp.), [[Gaylussacia baccata|black huckleberry]] (''Gaylussacia baccata''), a number of deciduous [[rhododendron]]s (azaleas), and smaller heaths such as [[Gaultheria procumbens|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 [[bryophyte]]s (mosses and liverworts), as well as [[fungi]]. Some species are rare and/or endemic. As with [[vascular plant]]s, 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 [[Lymantria dispar|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.

[[Appalachian bogs]] are [[boreal ecosystem]]s, which occur in many places in the Appalachians, particularly the [[Allegheny Mountains|Allegheny]] and [[Blue Ridge Mountains|Blue Ridge]] subranges.<ref>{{Cite web |url=https://www.fws.gov/southeast/pubs/mtbog.pdf |title=Info |website=www.fws.gov}}</ref><ref>{{Cite web |url=https://www.fws.gov/refuge/mountain_bogs/ |title=Home – Mountain Bogs – U.S. Fish and Wildlife Service |website=www.fws.gov}}</ref> Though popularly called [[bog]]s, many of them are technically [[fen]]s.<ref>Archived at [https://ghostarchive.org/varchive/youtube/20211211/YF0QNPA8IsM Ghostarchive]{{cbignore}} and the [https://web.archive.org/web/20190202060824/https://www.youtube.com/watch?v=YF0QNPA8IsM&gl=US&hl=en Wayback Machine]{{cbignore}}: {{Cite web |url=https://www.youtube.com/watch?v=YF0QNPA8IsM&index=32&list=PLnN7OGI1bJ88pzzjPYF-U6pgYTwj_8nHe |title=Southern Appalachian Cranberry Bog |last=expeditionspatrick |date=November 24, 2010 |via=YouTube}}{{cbignore}}</ref>

Several mountain summits in the southern Appalachians are covered with expansive open habitats (either grassy [[meadow]]s or [[heath]]) known as [[Appalachian balds]]. These habitats support many unique plant and animal communities, including rare, [[Relict (biology)|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 [[American bison|bison]], [[elk]], and deer) and [[Native American use of fire in ecosystems|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.<ref>{{Cite web|title=NatureServe Explorer 2.0|url=https://explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.723195/Southern_Appalachian_Grass_and_Shrub_Bald|access-date=May 31, 2021|website=explorer.natureserve.org}}</ref><ref>{{Cite web|title=Discovering the Southern Appalachian Grassy Balds - Office of the Vice President for Research {{!}} University of South Carolina|url=https://sc.edu/about/offices_and_divisions/research/news_and_pubs/caravel/archive/2015/2015-caravel-appalachian-balds.php|access-date=May 31, 2021|website=sc.edu}}</ref>
 
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]].<ref>{{Cite web|date=April 22, 2015|title=In the Zone: Exploring the Ecozones of the White Mountains|url=https://www.outdoors.org/resources/amc-outdoors/conservation-and-climate/in-the-zone/|access-date=May 31, 2021|website=Appalachian Mountain Club}}</ref><ref>{{Cite journal|last1=Carlson|first1=Bradley Z.|last2=Munroe|first2=Jeffrey S.|last3=Hegman|first3=Bill|date=August 1, 2011|title=Distribution of Alpine Tundra in the Adirondack Mountains of New York, U.S.A.|journal=Arctic, Antarctic, and Alpine Research|volume=43|issue=3|pages=331–342|doi=10.1657/1938-4246-43.3.331|bibcode=2011AAAR...43..331C |s2cid=53579861|issn=1523-0430|doi-access=free}}</ref><ref>{{Cite news|last=Regenold|first=Stephen|date=October 12, 2007|title=A Pocket of Alpine Tundra Nestled Atop New England|work=The New York Times|url=https://www.nytimes.com/2007/10/12/travel/escapes/12trek.html|access-date=May 31, 2021|issn=0362-4331}}</ref>

===Fauna===
[[File:Southern Flying Squirrel-27527-3.jpg|thumb|[[Southern flying squirrel]]]]
[[File:Wild Turkey-27527-1.jpg|thumb|A male [[Wild turkey|eastern wild turkey]]]]
Animals that characterize the Appalachian forests include five species of [[tree squirrel]]s. 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 [[American red squirrel|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 [[eastern moose|moose]] (''Alces alces ''), found only in the north, and the [[elk]] (''Cervus canadensis''), which, although once [[Eastern elk|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 [[North American beaver|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 [[American black bear|black bear]] (''Ursus americanus''), [[striped skunk]] (''Mephitis mephitis''), [[raccoon]] (''Procyon lotor''), [[Virginia opossum|opossum]] (''Didelphis virginianus''), [[groundhog|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 wolf|red wolves]] (''Canis rufus''). European [[Wild boar|boars]] (''Sus scrofa'') were introduced in the early 20th century.

Characteristic birds of the forest are [[wild turkey]] (''Meleagris gallopavo silvestris''), [[ruffed grouse]] (''Bonasa umbellus''), [[mourning dove]] (''Zenaida macroura''), [[common raven]] (''Corvus corax''), [[wood duck]] (''Aix sponsa''), [[great horned owl]] (''Bubo virginianus''), [[barred owl]] (''Strix varia''), [[Scops owl|screech owl]] (''Megascops asio''), [[red-tailed hawk]] (''Buteo jamaicensis''), [[red-shouldered hawk]] (''Buteo lineatus''), and [[American goshawk|northern goshawk]], as well as a great variety of "songbirds" ([[Passeriformes]]), like the warblers in particular.

Of great importance are the many species of [[salamander]]s and, in particular, the [[lungless salamander|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 newt|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 peeper]]s (''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 viper]]s. There are few lizards, but the [[broad-headed skink]] (''Eumeces laticeps''), at up to {{convert|13|in|cm|abbr=on}} 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 [[Etheostomatinae|darters]] (''Percina'' spp.) are also abundant.<ref>Page, Lawrence M. and Brooks M. Burr 1991, ''A Field Guide to Freshwater Fishes, North America, North of Mexico'', Houghton Mifflin Co., Boston</ref>

A characteristic fish of shaded, cool Appalachian forest streams is the [[Brook trout|wild brook or speckled trout]] (''Salvelinus fontinalis''), which is much sought after as a game fish.<ref>{{Cite thesis |title=Brook trout (''Salvelinus fontinalis'') movement and habitat use in a headwater stream of the central Appalachian Mountains of West Virginia |url=http://dx.doi.org/10.33915/etd.1798 |publisher=West Virginia University Libraries |first=Marisa Nel |last=Logan|date=2003 |doi=10.33915/etd.1798 }}</ref><ref>{{Cite web |title=Brook Trout (''Salvelinus fontinalis'') - Species Profile |url=https://nas.er.usgs.gov/queries/FactSheet.aspx?SpeciesID=939 |access-date=2024-06-02 |website=USGS Nonindigenous Aquatic Species Database}}</ref>