Tennessee's High-elevation Ecosystems

What are High-elevation

Ecosystems?Between the heights of 4,400 feet inthe Great Smoky Mountains NationalPark in Tennessee and 6,684feet ontop of Mount Mitchell in NorthCarolina's Black Mountain Range liethe unique and often mysterious high-elevation ecosystems of the SouthernAppalachians. The Appalachians areconsidered one ofthe oldest mountainranges in existence. Long ago thesemountains soared higher than theRocky Mountains and Swiss Alps, butover the eons they have graduallyworn down to their present heights bynatural erosion processes. The highslopes, domes, peaks, and ridges ofeastern Tennessee, western NorthCarolina and southwestern Virginiapossess a climate similar to Canada'sand are home to islandlike patches ofspruce-fir forests, rocky cliffs, andmountain balds.

The Southern Appalachians were notcovered with ice during the full glacialperiod of the last Ice Age nor werethey ever flooded by oceans. Whileevolution was slowed or halted in thefrozen parts of the world forthousands of years, plants andanimals of this region continued tothrive and evolve. Geological stabilitycombined with diverse climate andtopography have made the SouthernAppalachians one of the mostbiologically diverse regions in theworld. This diversity is reflected inour high-elevation ecosystems.

Southern Appalachian spruce-firforests typically are found above 5,50feet, grading into stands of northernhardwoods at lower elevations.Accompanying the red spruce andFraser fir at their lower limits arescattered yellow birch, Americanmountain ash, sugar maple, mountainmaple, and a variety of shrubs andherbaceous plants. The shallow rockysoils are acidic and generally coveredwith a thick organic layer.Biologically unique, these forestsprovide us with a living museum fromanother time. Thousands of years ag

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spruce-fir forests covered thesurrounding valleys and mountainpeaks of the Southern Appalachians.As the glaciers retreated and theclimate warmed, the spruce-fIr forestswithdrew to the tops of our highestmountains and spread northward.During this progression the high-elevation species of the SouthernAppalachians are believed to havecontributed to the evolution of thewidespread boreal forests of theNorthern United States and Canada.Thus, the only true relict ecosystem ofthe spruce-fir forest lies in theSouthern Appalachians, where it haspersisted continuously over the last18,000years. Today these southernmountaintop forests are characterizedby a number of plants and animalsfound nowhere else on earth, alongwith other species that are commontoday only in sub-Arctic regions.

High-elevation cliffs and rockyoutcrops can be found on many ridgesand valleys in the SouthernAppalachians. These ecosystems

were molded over time by the harshconditions of exposure to extremecold and winds of up to 130miles anhour. Although these rocky areasseem bare at fIrst glance, theyactually provide habitat for severalrelict tundralike species that haveadapted to the extreme climate.

Grassy balds share the ridge tops and"saddles" of the highest peaks in theSouthern Appalachians. Theseunique ecosystems appear to be largegrassy meadows in the forest, withazaleas, rhododendrons, and othershrubs scattered across them. Theirlocation and unusual plant life provethat many of the balds are quite old.Generations of mountain residentshave pondered how and why thesehigh-elevation meadows came to be.Our Southern peaks are hospitablefor tree growth, so how is it that theseareas are not forested.

Some believe the balds have pre-Cherokee origins. Perhaps earlyNative Americans cleared the balds to

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improve hunting or to look forapproaching enemies. Somescientists hypothesize that acatastrophic fire long ago played apart in the creation of mountain balds.Early mountain grazers, such as elkand bison, may have kept these baldareas clear of trees.

Why are High-elevation

Ecosystems Important?The high-elevation ecosystems of theSouthern Appalachians arebiologically unique and geographicallyrestricted and support an abundanceof rare plants and animals. Becauseof their antiquity and ancestralaffinity to the northern coniferousforests, they are a wealth of diversityand a tremendous and largelyunrealized scientific resource. Also,because they sit at the headwaters ofmountain streams, they are extremelyvaluable for watershed protection.Their canopy and understoryvegetation slows down and filtersrainwater. Thus, they greatly benefitthe water quality of these streamsand enhance downstream fisheries.

High-elevation ecosystems areaesthetically important torecreational users. Hundreds ofthousands ofvisitors flock to theSouthern Appalachian Mountainseach year for backpacking, naturewalks, camping, picnicking,photography, and driving forpleasure. Mount Mitchell State Parkin North Carolina, the Blue RidgeParkway and the Great SmokyMountains National Park in NorthCarolina and Tennessee, and MountRogers National Recreation Area inVirginia provide opportunities forpeople from all over the country toescape to the peace and beauty ofmountains that are still wildand unspoiled.

Diversity of Life in

High-elevation Ecosystems

High-elevation ecosystems providehabitats for an impressive diversity owildlife. Many mammals visit thesemountaintops, and some make theirhomes there year-round. Big brownbats, red squirrels, easternchipmunks, woodland jumping mice,gray foxes, spotted skunks, bobcats,and black bears have all been spotted

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feeding and taking shelter in high-elevation ecosystems. The diversityof bird species here thrills visitingbirders, who may be lucky enough toglimpse the rare American peregrinefalcon, red crossbill, red-breastednuthatch, snow bunting, raven, black-throated green warbler, black-throated blue warbler, Canadawarbler, and magnolia warbler.

Many of our high-elevation speciesare rare, some so rare that they arenearing extinction and are federallylisted as endangered or threatened.The Southern spruce-fir forestsprovide the only remaining habitatfor the endangered Carolinanorthern flying squirrel and spruce-fir moss spider. These forestssupport rare plants and unusualamphibians, such as imitator andpigmy salamanders. The elusivesaw-whet owldepends on theseforests, along with rare mammals,such as the masked, long-tailed, andpygmy shrews. Unfortunately, eventhe Fraser fir itself is in significantdecline and is considered a speciesof federal concern.

Grassy balds are home to the rareGray's lily and purple gentian andthe endangered Roan Mountainbluet and spreading avens.Greenland sandwort, bent avens,and Arctic bent grass can also befound in these mountaintopgrasslands. High-elevation cliffsand rocky outcrops can providesuitable habitat for the endangeredperegrine falcon, spreading avens,and rock gnome lichen, and thethreatened Heller's blazing star andBlue Ridge goldenrod.

Threats to High-elevation

EcosystemsAlthough high-elevation ecosystemsappear rugged, they are extremelyfragile. A number of factors threatenthese valuable ecosystems, includingatmospheric pollution, climatechange, disease, insect damage, andother factors not yet fully understood.Spruce-fir forests have been reducedby as much as 50 percent, primarilyas a result of logging followedbysevere fires in the earlier part of thiscentury. These forests are now beingdecimated by an exotic species-the balsam wooly adelgid. The

balsam wooly adelgid, native toEurope, was first identified in Mainein 1908. It probably arrived prior to1900on imported nursery stock. Thistiny sucking insect feeds on the innerbark of true fir trees, causing theirdeath within 2 to 7 years afterinfestation. This wingless pest isdispersed by the wind and probablycame to the Southern Appalachians asearly as the 1940s. Mount Mitchell inNorth Carolina was found to beinfested in 1957,and surroundingSouthern Appalachian spruce-firforests were found to be infested by1963. The balsam wooly adelgid hassince been found in every Fraser firstand. Unfortunately, Fraser fir isthe most sensitive fir species tobalsam wooly adelgid infestation.The spread of the adelgid throughoutSouthern spruce-fir forestcommunities has resulted in themassive mortality of mature Fraserfirs. Losing one of the dominantcanopy species has, in turn, causedmajor changes in temperature andmoisture levels in the understory,threatening numerous other speciesthat rely on the cool,moist conditionsmaintained by the fir. Othernonnative species, such as theEuropean wild boar, also damagehigh-elevation ecosystems. Boarsroot and destroy sensitive habitatsand the roots of trees and plants.Exotic grasses, like Timothy grass,often choke out native plants.

Because of their severe climate, highmountain ecosystems may beespecially prone to air pollution.However, the effects of pollutants aredifficult to separate from the effectsof oth.er factors, like the balsam woolyadelgId; so, the role that air pollutionhas played in the reduction of spruce-fir forests is not fully understood.

Regardless of the causes of Fraser firdecline, the disappearance of thisdominant tree species has adverselyaffected other members of theecosystem. For instance, the loss ofFraser firs, having created openingsin the canopy, has exposed the redspruce trees to high winds, causingthe trees to fall. As these forestsdisappear the moisture available toneighboring cliffs and mountainbalds decreases.

High-elevation ecosystems face otherthreats as well. The heavy humantraffic through these beautiful areasexposes the rare species that live hereto many dangers. Cliff edges, rockoutcrops, moss-covered boulders, andgrassy balds are particularlyattractive to hikers, rock climbers,and picnickers. As a result, tramplinghas become a severe threat to manyrare plant and small animalpopulations, like salamanders andspiders. Thousands of people visitthese mountains year after year andare not aware of the sensitive natureof the landscape, where soils are soshallow one stomp can crush a rareplant. A moss mat on a singleboulder, easily destroyed bytrampling, may provide one of the lastrefuges for a rare species like thespruce-fir moss spider. Picking anddigging up wildflowers createsanother substantial threat; a rarepopulation of 100plants could easilybe wiped out by flower collection. Thcareless or deliberate cutting of livetrees or saplings for firewood and thecreation of illegal campsites furtherthreaten these pressured ecosystems.

What's Being Done?Most of the high-elevation ecosystemsof the Southern Appalachians areowned or managed by federal or stategovernments. In addition to theacreage contained within the GreatSmoky Mountains National Park,Mount Mitchell State Park, theBalsam Mountains, and MountRogers National Recreation Area,about 10,000acres of the crest of theRoan Mountain massif are owned andmanaged by the U.S. Forest Service.There are 7,000acres in the PisgahNational Forest, and 3,000 acres arepart of the Cherokee National Forest.The public ownership of these landshelps to ensure their existence for ouuse and enjoyment and for that offuture generations.

Efforts are underway to protect andrestore high-elevation ecosystems.Signs and barriers warning ofsensitive habitats have been posted atmany rocky outcrops to help visitorstreat ecosystems responsibly. Goatshave been used to graze and maintaingrassy balds. Researchers areattempting to develop methods to

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control the balsam wooly adelgid.However, the remoteness of theseareas and the difficulty in treating thetrees, while not impacting otherspecies, presents significant logisticalchallenges. It is hoped that abreakthrough treatment will bedeveloped that is inexpensive andeasily applied so that the balsamwooly adelgid will one day cease to bea pest in these ecosystems. Also,conservation organizations and thescientific community continue toresearch the effects of atmosphericdeposition and other factors harmingthe health of our high-elevationecosystems, hoping that managementsolutions to these perplexingproblems will be discovered.

Seeing is Believing!Tennessee has many trails, parks, andnatural areas where you can get aclose-up view ofwild plants andcreatures and their habitats. Usingthe supplemental Tennessee WildlifeViewing Guide, locate and visit ahigh-elevation ecosystem, but keep inmind the uniqueness and fragility ofwhat you are enjoying!

Remember, although high-elevation ecosystems appearrugge~ they are quite fragile.Always stay on trails andboardwalks to avoidtrampling or damagingvegetation. Avoid climbingon rocky outcrops and moss-covered boulders; thesehabitats and the species theysupport are extremely fragileand easily destroyed. Avoidpicking wildflowers insensitive ecosystems. Camponly at authorized sites andcomply with the regulationsor the use of these sites. Readand pay attention to signswarning of sensitive habitats.Continue to learn and theneducate others about high-elevation ecosystems. Takepride in and enjoy ourhigh-elevation ecosystems!

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Spruce-fir Moss Spider(Microhexura motivaga)

Tell afriend about thespruce-fir rrwss spider.Protect high-elevationecosystems by preventingair pollution. Stay ontrails when hiking in highrrwuntains to avoidtrampling unique habitats.Avoid climbing on vegetatedrocky outcrops andboulders. Take pride inTennessee's wildlife!

StatusThe spruce-fir mossspider was listed asendangered onFebruary 6, 1995.

DescriptionThe spruce-firmoss spider is theworld's smallesttarantula. Adults areabout the size of a BB,measuring only 3 to5 millimeters across.These tiny spidersrange in color fromlight brown to yellowor reddish brown.

HabitatThe spruce-fir moss spider dependson Southern Appalachian spruce-firforests. There are only three smallpopulations of this high-elevationspecies-two in North Carolina andone in Sevier County, Tennessee. Thespider's habitat is made up of damp,well-shaded moss mats that grow ontop of rocks and boulders. The spiderbuilds tube-shaped webs between themoss mats and the rock surface. Themats must have just the right amountof moisture; too much water coulddrown the tiny spider and too littlecould cause it to dry out.

Life HistoryLittle is known about the secretivespruce-fir moss spider; its breedinghabits and life span are a mystery.

Role in the EcosystemThe diet of the spruce-fir moss spiderisn't known, but springtails (tinycreatures that share the spider'shabitat) may be a likely food source.Many types of spiders are known tobe important food sources for birds,lizards, wasps, and other animals.Spider silk is important to many birdspecies for nest building. Did youknow that spider silk is very elastic,and twice as strong as steel!Researchers are currentlyinvestigating tarantula venom formedicinal uses. The venom may

Actual Size

•1--15mm

provide a treatment for Alzheimer'sand Parkinson's diseases andmay help prevent brain damage instroke patients.

ThreatsThe spruce-fIr moss spider isthreatened by the loss of its spruce-firforest ecosystem. The death andthinning of these high-elevationforests result in increasedtemperatures and decreasedmoisture, which cause the spider'smoss mat habitat to dry out. As themoss mats dry out, so do the spiders.Spruce-fIr forests have declinedbecause of an exotic insect (thebalsam wooly adelgid), and airpollution seems to have played a partin the loss of these unique forests.

RecoveryEfforts are underway to establish acaptive-breeding program for thespruce-fir moss spider. Studies of thespider's life history, habitatrequirements, and threats to itsspruce-fir ecosystem will continue andmay provide further insight intorecovery actions.

Rock Gnome Lichen

Tell afriend about the rockgnome lichen. Protect high-elevation ecosystems bysupporting loca~ regiona~and national clean airstandards. Stay on trailswhen hiking in highmountains to avoidtrampling unique habitats.Avoid climbing on vegetatedrocky outcrops andboulders. Pay attention tosigns that prevent access tosensitive mountainhabitats. Take pride inTennessee's wild lichens!

StatusThe rock gnome lichen was listed asendangered on January 18,1995.

DescriptionThe rock gnome lichen grows in\dense colonies of narrow, straplikestructures. Each strap is only about2 centimeters long, and the tip ofeach strap curls upward. The lichenis blue-gray above and shiny whitebelow. A lichen is a combination of afungus and an algae. Together theyform a new organism, supportingeach other in environments wherethey could not survive alone; thisprocess is called mutualism. Thealgae photosynthesizes and obtainsenergy from the sun, while the fungusprovides structure for the organism.

HabitatThe rock gnome lichen is found inthe Southern Appalachian Mountainsof North Carolina and Tennessee.It occurs only in areas with highhumidity, either in high areas whereit is frequently bathed in fog or indeep river gorges at lower elevations.The rock gnome lichen has veryspecific requirements for light andmoisture. It grows on bare rock facesor cliffs,where water seeps fromabove the forests on very wet days.Most populations are above 5,000feetin elevation. Currently there are32 remaining populations of the rockgnome lichen. Only seven of these arelarger than 2 square meters, andmost of the populations are less than1 square meter in size.

Life HistoryLichens spread when smallfragments are broken off andbecome attached to other patches ofrock. New colonies form from thesesmall fragments.

Role in the EcosystemLichens do not need an organic foodsource; they require only light, air,and a few minerals. The rock gnomelichen gets some minerals from itsrocky cliffhome, but most mineralsreach the lichen through the air and

in rainfall. Lichens are often the fIrstorganisms to grow on bare rockyareas. Their presence slowly changesthe surface environment, graduallycreating new habitat for mosses,ferns, and other plants. Becauselichens quickly soak up substances inrainwater, they are very sensitive toairborne pollution. The presence orabsence of lichens can indicate thequality of the air in a particular area;where lichens thrive, the air is goodfor people and creatures to breathe.

ThreatsThe rock gnome lichen has declinedfor several reasons. Its rocky habitatmakes it susceptible to trampling byoutdoor enthusiasts who are unawareof its presence. Hikers, climbers, andsightseers crush the lichen as theyclimb around on its rocky home.The nearby spruce-fir forests havedeclined because of the balsam woolyadelgid, an exotic insect, and airbornepollution. As these forests disappear,the moisture available to the lichendecreases, and the lichen dries out.Because lichens are sensitive toairborne pollution, it is suspected thatfurther decline has been caused bypoor air quality and polluted fog.

RecoveryNearly all of the remainingpopulations of the rock gnome lichenare on public land. The U.S. ForestService and the National Park Serviceare working with the U.S. Fish andWildlife Service to protect the speciesfrom trampling and collection.Efforts are also underway to monitorthe effects of air pollution on this rarelichen. The North Carolina andTennessee Natural HeritagePrograms, the North Carolina PlantConservation Program, and TheNature Conservancy also work toprotect the rock gnome lichen.

Carolina Northern Flying Squirrel(Glaucomys sabrinus coloratus)

Tell afriend about theCarolina northern flyingsquirrel. Protect high-elevation ecosystems bysupporting local, regional,and national clean airstandards. Take a breakfrom your car; walk to thestore, post office, or school.Protect air quality byconserving electricity; turnoff the lights. Take pride inTennessee's wildlife!

StatusThe Carolina northern flyingsquirrel was listed as endangered onJuly 1, 1985.

DescriptionThe Carolina northern flyingsquirrel is a small gray mammal witha whitish underside. Adults weighabout 3 to 5 ounces, or about asmuch as a banana, and grow to alength of about 10 to 12inches. Thesquirrel has large eyes, silky fur, anda long, flattened tail. Folds of skinstretch between the squirrel's wristsand ankles. To travel, it leaps, andthese folds of skin stretch out to helpthe squirrel "parachute," or glide,from tree to tree. The Carolinanorthern flying squirrel isnocturnal-active at night.

HabitatCarolina northern flying squirrelsdepend on high-elevationforests in the Southern AppalachianMountains of North Carolina andTennessee. They occur in thetransition, or overlap, area betweenthe high peaks, domes, and ridges ofthe spruce-fir forests and thenorthern hardwood forests, whichgrow at lower elevations. Hollowtrees in the oak-dominated hardwoodforests provide nesting cavities for thesquirrels. Both the spruce-fir andhardwood forests are used in theirsearch for food. They prefer olderforests, with widely spaced tall treesthat are easy to glide between.

Life HistoryCarolina northern flying squirrelsnest in tree cavities, which they linewith lichens, moss, and finely chewedbark. Two to six young are producedeach spring. Little is known aboutthis rare squirrel's life, but it isbelieved that they live in smallfamily groups of adults and youngsquirrels. They remain activethroughout the winter.

Role in the EcosystemCarolina northern flying squirrels eatlichens and fungi, seeds, buds, fruit,and insects. These squirrels may helpmaintain the forests by dispersingnitrogen-fixing bacteria and fungalspores that are needed by trees forproper growth.

Threats

The Carolina northern flying squirrelis adapted to the cold, harshconditions of the SouthernAppalachian high-elevationecosystems. It is thought thatpopulations of the squirrel have beenshrinking due to natural conditionssince the last Ice Age. The species isnow isolated in small, restricted areas,and the decline of SouthernAppalachian spruce-fir forests, due toexotic insect invasions and otherfactors, threatens the squirrel withextinction. Habitat decline has alsocaused increased competition fornesting habitat between the Carolinanorthern flying squirrel and its lower-elevation counterpart, the southernflying squirrel.

Recovery

The primary recovery goal for theCarolina northern flying squirrel is tolearn more about this elusive species'habitat requirements, diet, andrelations with other species. Oncethese squirrels are better understood,more effective management decisionscan be made. Efforts are being madeto protect the areas where thesquirrel is known to live.