The Barrens-Tennessee's Prairie Ecosystems

We can ensure that barrensecosystems will continue tobe a part of Tennessee'snatural beauty. Everycitizen can help protect andrestore these ecosystems.Every little bit counts!Here's how: Do not pickwildflowers. Remember tostay on trails to avoidtrampling plants andanimals. Support state andlocal habitat conservationand natural areas protectionefforts. Learn more aboutfire's important role inecosystem function.Continue to educate yourselfand others about barrensecosystems and the speciesthey support. Use nativewildflowers propagated bylocal nurseries forlandscaping around yourhome. Take pride in andenjoy Tennessee's barrensecosystems!

What Are Barrens?Tennessee's barrens ecosystems area mosaic of open canopy woodlandswith a grassy understory and areasof essentially treeless grassland.Various types of barrens are found,sparsely scattered from the Ridgeand Valley Province to westTennessee. They are best developedand most extensive on the EasternHighland Rim, Western HighlandRim, and Pennyroyal Plain. Alongthe Kentucky border these areaswere named prairies, or meadows ofgrass, by early French explorers.Early Anglo land surveyors namedthese savanna-like areas the barrensbecause of their relative barenessof trees.

The barrens ecosystems of Tennesseeappear similar to the Midwestern tall-grass prairies but originated at adifferent time. One type of barren isclosely associated with the cedarglade ecosystems. Barrens havedeeper soil, less exposed bedrock, andmore perennial grass cover than theseneighboring cedar glade ecosystems.

Based on fossil pollen records, it isthought that the barrens becameestablished near the end of theHypsithermal period, a hot dry time

that occurred 4,000 to 8,000years ago.The climate of the time was notfavorable for forest growth and gavespecies typical of prairies anopportunity to form prairielikecommunities. The soils also played animportant role in the development ofthe prairies.

The original soils were derived fromlimestone, which was then covered bya thin layer of wind-blown material,called "loess," that originated fromrocks ground by glacial scouring. Ai>water trickled through the top layerdown to the limestone-derived claybelow, moisture accumulated betweenthe loess and the clay. Minerals in thewater collected in cementlike layers toform the "hardpan soils." Thehardpan soils of the EasternHighland Rim kept soils saturated inthe winter and droughty in thesummer, which allowed the prairieplant community to form andinhibited tree growth. Without trees,fire spread easily on the flatlandscape, with grasses providing fuelfor the fires.

Since that time our climate hasfavored the development of forests,and the barrens have shrunkconsiderably. It is thought that the

remaining barrens were historicallymaintained by wildfires and the firesof Native Americans, which restrictedthe spread of trees and otherwoody plants.

Why are Barrens EcosystemsImportant?

The barrens ecosystems represent aremnant of what was once probably amuch larger ecosystem. Theprotection of remaining tracts ofbarrens and the restoration of areashistorically occupied by theseecosystems offers the return of a nowglobally rare tall-grass communities.These ecosystems also offer us theopportunity to observe processes thatare typical within the barrens, whichconstitute a living laboratory.

Barrens ecosystems provide habitatsfor a variety of beautiful wildflowers.Botanists and the general public flockto these small grasslands from Maythrough June to view the springcolors of Indian paintbrush, wild bluefalse indigo, colicroot, and others.Late summer and early fall provideanother opportunity for wildflowerenthusiasts as Southern prairie-dock;blazing star; sunflowers; yellow, pink,and purple asters; and bloominggrasses decorate the landscape.

Rare and Unique Species

Depend on Barrens EcosystemsBarrens ecosystems support aremarkably diverse array of plantsand animals. Species of theMidwestern tall-grass prairies, suchas big bluestem, little bluestem,yellow Indian grass, and switchgrass,can be found here. Disjunct speciestypically found in the coastal plains ofthe Atlantic Ocean and Gulf of Mexicocan also be found here. Falseasphodel and snowy orchids, are twospecies that occur at one site in thebarrens of the Eastern Highland Rimand nowhere else in Tennessee. Theprairie gentian and pale-purpleconeflower each occur at only one sitein Tennessee's barrens and aretypically found in Midwestern tall-grass prairies.

Rare and declining plants and animalsdepend on the barrens. Recentdecades have brought the decline ofbetween 25 and 65 percent ofgrassland-dependent species of birds,such as grasshopper sparrows andprairie warblers. Amphibians, likethe dusky gopher frog, will disappearfrom Tennessee if the barrensecosystems continue to shrink. The

barrens ecosystems support morethan 300 species and subspecies ofplants, and Tennessee has listed morethan 25 barrens-associated plants asendangered, threatened, or of specialconcern, such as Southern prairie-dock and swamp lousewort. Eggert'ssunflower is federally threatened, andthe endangered American chaffseed isbelieved to be extirpated fromthe state.

Threats to Barrens EcosystemsBecause barrens are often relativelyflat, much of Tennessee's barrenshave been converted to agriculture orhave been covered by forests due tofIre suppression. Hardpan soilscritical to the survival of prairielikespecies have been broken up toimprove agriculture. The use of fIreby Native Americans was notcontinued by European settlers, andsince 1945state laws and the use offences have prevented open rangeand woodland fires, allowing trees andother woody plants to spread furtherinto the declining barrens. Theintroduction and wide-scale use ofexotic species like cool-season fescuehas taken over barrens, edging outnative species. The digging of ditchesand the resulting drainage haspromoted further invasion of woodyspecies into the grasslands. Thedevelopment of residential housingand industrial facilities and theoutright destruction of barrens bypaving roads and establishing lawnshave caused this rare ecosystem todecline further.

What's Being Done?Efforts are being made in Tennesseeto protect and restore the barrensecosystems. Prescribed burning atselected sites is helping to reduce thespread ofwoody species into thebarrens. Barrens restoration includesprescribed burning and herbicidetreatments to eliminate exotic fescue.This restoration is being donecooperatively with the TennesseeWildlife Resources Agency, theTennessee Department ofAgriculture's Division of Forestry,and the Tennessee Department ofEnvironment and Conservation'sNatural Heritage Division (undertheir Natural Areas Program). Also,Arnold Air Force Base is workingwith the U.S. Fish and WildlifeService, The Nature Conservancy,and other partners to completespecies inventories and test variousmanagement practices for restoringor maintaining barrens habitat.

An essential part of barrensrestoration is land protection. Stateagencies and The NatureConservancy are active in this area.One area in Tennessee that has beenprotected is May Prairie. May Prairieis a small area of less than 20 acres ofbarrens that was purchased by thestate in 1975as part of a larger tract.Tennessee's Natural AreasPreservation Act of 1971protectedthe area now known as the MayPrairie Designated State NaturalArea. May Prairie was alsoregistered as a National NaturalLandmark by the National ParkService in 1981. Current effortsinclude linking isolated prairies andclearing young timber from formerprairie areas.

Seeing is Believing!Tennessee has many trails, parks, andnatural areas where you can get aclose-up view of wild plants andcreatures and their habitats. Usingthe supplemental Tennessee WildlifeViewing Guide, locate and visit abarrens ecosystem when thewildflowers are in bloom!

Eggert's Sunflower(Helianthus eggertiO

Tell afriend aboutEggert's sunflower. Avoidpicking wildflowers.Remember to stay on trailsto avoid trampling uniqueplants. Learn aboutjire'simportant role in ecosystemfunction. Take pride inTennessee's wildflowers!

StatusEggert's sunflower was listed asthreatened on June 23, 1997.

DescriptionEggert's sunflower is a tall memberof the aster family; it grows to about8 feet in height. The plant has a blue-waxy coloration with whitish lowerleaves. The plant's pointed leaves are10 to 20 centimeters long. Theflowers are large and yellow, and theybloom from early August throughearly October. The seeds are blackishor grayish and mottled. Theextensive root system of thissunflower can live for several years;thus, the plant does not need toproduce seeds every year to ensureits survival.

HabitatEggert's sunflower depends on thebarrens ecosystems. It typicallyoccurs on rolling to flat uplands and inareas that receive full sun or partialshade. There are 34 populations ofthis rare plant in Tennessee,Alabama, and Kentucky. Tennessee'spopulations occur within the barrensof the Highland Rim and CentralBasin.

Role in the EcosystemThe flowers and seeds of this plantare enjoyed by insects, such as bees,and birds. This plant is part of thediversity of life within barrens andadds to the health of the ecosystem.In addition, many wild species ofsunflowers have been used to developtoday's highly productive and diseaseresistant commercial sunflower crops.Scientists will continue to look to wildpopulations of plants to improve ourcommercial crops, so conservation ofwild plant species is important.

ThreatsEggert's sunflower is threatened withhabitat destruction. Residential,commercial, and industrialdevelopment and conversion to cropand pasture land continues to reducethe barrens of Tennessee. Firesuppression has allowed Eggert'ssunflower to be threatened by thespread and succession of other plantsinto its habitat. Herbicide use alongnearby roadways also poses a threatto this rare plant.

Recovery

The Tennessee Wildlife ResourcesAgency and the TennesseeDepartment of Environment andConservation's Division of Forestryand their Natural Heritage Programare working together to restoreTennessee's barrens, usingprescribed burning and othermethods of restoration. Arnold AirForce Base is home to the state'slargest population of Eggert'ssunflower, and they are working withThe Nature Conservancy to manageand protect this rare plant.