The Piedmont Prairie

The Natural History of the Piedmont Prairie

The term piedmont prairie describes the grassland ecosystem that once covered a substantial part of the U.S. southeastern Piedmont region. The rolling landscape of the Piedmont (French for foothills) stretches from New Jersey to central Alabama, covering an area of approximately 80,000 square miles.

It is wedged between the Blue Ridge Mountains to the west and the coastal plain to the east, being 300 miles at its widest in North Carolina. Early French explorers traveling through the North American continent used the term prairie to describe the vast grasslands that once covered a large portion of the North American Midwest.

This old French map of the Carolinas and Virginia has the wording Grand Savanne in the area that would now be covered by the North Carolina piedmont. These grasslands were grazed by large herbivores, including bison and elk. Mark Catesby (1683 – 1749), an English botanist traveling through the region, observed “buffalo retiring to the river cane during the heat of the day,” coming out to graze at dusk and dawn. The animal waste would add to the fertility of the soil. 

Fire and Grazing

These southern grasslands, as with the northern prairies, were formed not only through grazing but also with fire. Initially wildfires would take place during thunderstorms, from lightning strikes. The fires could burn extensively, clearing vegetation from large tracts of ground. Palatable grasses and wild flowers would regrow, attracting the bison. Over hundreds if not thousands of years, the grassland ecosystem evolved.

A significant proportion of fires were started and controlled by the Indigenous population.  Fire has been used as an agricultural management tool worldwide, to clear tracks, flush out game, control insect pests and restrict the regrowth of forests.

Indigenous Peoples of the Carolinas

The map below shows some of the Native American nations that inhabited the northern region of the Carolinas in 1500 CE.  Prior to the arrival of the European explorers in the late 15th century, it has been estimated that the southeastern U.S. was home to 2 million people.  This Indigenous population originated from Asia, moving to and migrating throughout the Americas some 10,000 to 30,000 years ago.

When the European colonists arrived in the southeastern piedmont in the late 17th century, they discovered grassland with a scattering of trees, termed savanna. In 1701, English explorer John Lawson, one of the first chroniclers of the Carolinas, traveled 300 miles with companions throughout the Carolina piedmont. In his diary, published in 1709, Lawson wrote about people they met, the food prepared and eaten, the animals encountered and the land journeyed. He describes many savannas and walking for 30 miles without seeing a single tree, as well as the frequent use of fire by the Indigenous population.

The loss of the Indigenous population due to disease and war, followed by the removal of the survivors from their land in the early 19th century, the loss of the native grazing herbivores (bison and elk), and the subsequent occupation and management of the land by European settlers, all  led to major changes in the piedmont landscape. These early settlers were subsistence farmers, producing enough food to feed their families. They were attracted to the open savannas with ready-made fields ripe for crop cultivation and for animals to graze. The use of fertilizer and crop rotation was not adopted by these early farmers, and over time the land lost fertility. In some cases fields were abandoned, leading to woodland regeneration, and the vast savannas were gradually lost from the southeastern piedmont.

Learn more about the indigenous people who still live in the Carolinas today in this Equity Through Stories multimedia research project by Duke student Quinn Smith.

Remnant Piedmont Prairies

The native grasses and wildflowers that once covered the southeastern piedmont are today relegated to surviving under power line “rights of way,” roadsides and old field margins.  There are a few rare and unique places scattered throughout the region, where it was not possible to cultivate the soil (i.e. plough) due to the nature of the soil.
One soil type has gradually eroded from diabase rocks, and this clay has extremely high shrinkage and swelling ability. When it rains, the water sits on the soil surface, with poor drainage. When it is very dry, the soil becomes rock hard, like a brick. This type of land was mowed for hay, grazed or allowed to transform back to  forest.

Examples of these soils are found at Prairie Creek in Granville County, Penny’s Bend in Durham County and Suther Prairie in Cabarrus County. These three remnant prairies contain rare and endangered plant species from the piedmont prairie and are currently under the protection of various North Carolina organisations, such as the North Carolina Department of Agriculture & Consumer Services’ Plant Conservation Program, Friends of Plant Conservation, the Eno River Organisation, the Prairie Ridge Ecostation, and the Ellerbe Creek Watershed Association.   

Building the Blomquist Piedmont Prairie

The goal of this project was to create in Duke Gardens a rendition of a landscape that once covered a large proportion of the Carolina piedmont. Duke Gardens attracts more than 600,000 visitors per year, and this landscape would be an opportunity to connect the visiting public with a vanishing ecosystem. 

Piedmont Prairie Plant List

These plants are considered linked to grassland ecosystems in the piedmont. They were propagated from local ecotype seed.

Agalinis purpurea (purple false foxglove)
Allium cernuum (nodding onion)
Ageratina altissima (white snakeroot)
Andropogon gerardii (big blue stem - grass)
Andropogon ternarius (splitbeard broomsedge - grass)
Andropogon virginicus (broomsedge - grass)
Antennaria plantaginifolia (pussytoes - woman’s tobacco)
Aristida purpurea (purple three awn - grass)
Asclepias incarnata (swamp milkweed)
Asclepias syriaca (common milkweed)
Asclepias tuberosa (butterfly milkweed)
Asclepias verticillata (whorled milkweed)
Baptisia australis abberans (blue wild indigo)
Baptisia alba (white wild indigo)
Blephilia ciliata (downy wood mint)
Ceanothus americanus (New Jersey tea)
Chamaecrista fasciculata (partridge pea)
Chamaecrista nictitans (sensitive pea)
Chrysogonum virginianum (green and gold)
Chrysopsis mariana (Maryland golden aster)
Coreopsis major (greater tickseed)
Coreopsis verticillate (thread leaf coreopsis)
Coreopsis tripteris (tall coreopsis) 
Echinacea laevigata (smooth leaved coneflower)
Echinacea purpurea (purple coneflower)
Elymus virginicus (Virginia wild rye)
Eragrostis spectabilis (purple love grass)
Eragrostis hirsute (big top love grass)
Erianthus giganteus (giant plume grass)
Erigeron annuus (daisy fleabane)
Eryngium yuccifolium (rattlesnake master)
Eupatorium album (white thoroughwort)
Eupatorium altissimum (tall thoroughwort)
Eupatorium hyssopifolium (hyssopleaf thoroughwort)
Eupatorium rotundifolium (roundleaf thoroughwort)
Eupatorium rugosum (white snakeroot)
Eupatorium serotinum (late boneset)
Eupatorium sessilifolium (upland boneset)
Helenium autumnale (common sneezeweed)
Helianthus atrorubens (purple disc sunflower
Helianthus decapetalus (thin leaf sunflower)
Helianthus divaricatus (rough sunflower)
Helianthus resinous (resin dot sunflower)
Helianthus schweinitzii (Schweinitz's sunflower)
Helianthus strumosus (pale leaved sunflower)
Helianthus tuberosus (Jerusalem artichoke)
Heliopsis helianthoides (rough ox-eye)
Houstonia spp. (bluets)
Hypericum prolificum (shrubby St. John's wort)
Hypericum hypericoides (St. Andrew’s cross)
Iris cristata (dwarf crested iris)
Liatris pilosa (shaggy blazing star)
Liatris spicata (dense blazing star)
Liatris squarrosa (scaly blazing star)
Liatris squarrulosa (Appalachian blazing star)
Lobelia cardinalis (cardinal flower)
Lobelia puberula (downy lobelia)
Manfreda virginica (false aloe)
Marshallia obovate (spoon shape Barbara’s buttons)
Marshallia legrandii (tall Barbara’s buttons)
Oenothera biennis (common evening primrose)
Oenothera fruticose (narrowleaf evening primrose)
Packera anonyma (Appalachian ragwort)
Panicum anceps (beaked panic grass)
Parthenium auriculatum (glade wild quinine)
Parthenium integrifolium (wild quinine)
Penstemon digitalis (foxglove penstemon)
Penstemon laevigatus (eastern smooth beardtongue)
Pycnanthemum incanum (hoary mountain mint)
Pycnanthemum tenuifolium (narrowleaf mountain mint)
Rhexia virginica (meadow beauty)
Rudbeckia fulgida (orange coneflower)
Rudbeckia hirta (black-eyed Susan)
Rudbeckia laciniata (cut leaf coneflower)
Rudbeckia triloba (brown-eyed Susan)
Schizachyrium scoparium (little blue stem - grass)
Scutellaria incana (downy skullcap)
Scutellaria integrifolia (helmet flower)
Silene virginica (fire pink)
Silphium asteriscus (starry rosinweed)
Silphium compositum (kidney leaf rosinweed)
Silphium dentatum (rough stem rosinweed)
Silphium terebinthinaceum (prairie dock)
Solidago bicolor (white goldenrod)
Solidago canadensis (Canada goldenrod)
Solidago erecta (slender goldenrod)
Solidago nemoralis (gray goldenrod)
Solidago ptarmacoides (prairie aster)
Solidago rugosa (wrinkle leaf goldenrod)
Solidago speciosa (showy goldenrod)
Sorghastrum nutans (Indian grass)
Symphyotrichum concolor (eastern silver aster)
Symphyotrichum depauperum (serpentine aster)
Symphyotrichum georgianum (Georgia aster)
Symphyotrichum grandiflorum (large flower aster)
Symphyotrichum leave (smooth blue aster)
Symphyotrichum patens (late purple aster)
Symphyotrichum pilosum (frost aster)
Symphyotrichum puniceum (swamp aster)
Tephrosia virginiana (goat's rue)
Trichostema dichotomum (forked blue curls)
Tridens flavus (purple top - grass)
Verbena simplex (narrow leafed vervain)
Verbena hastata (swamp vervain)
Vernonia noveboracensis (New York ironweed)

References

Anderson R. C. (2006) J of the Torrey Botanical Society 133, 626 – 647: Origin and Evolution of the Central Grassland of North America

Rasmussen R. et al.  (2014); Nature 506, 225 – 229

Raff J and D. Bolnick, (2014); Nature 506, 162-163

Tompkins, R.D. and W. C. Bridges Jr. (2013); Restoration and species diversity of an Eastern Prairie. Native Plants Journal 14 101-113

Barden, L.S., (1997); Historic Prairies in the Piedmont of North and South Carolina.
Natural Areas Resource Journal; 17 149-152

David, J.E, McRAe, C., Estes BL Barden LS (2002); Vascular flora of Piedmont Prairie 
Evidence from several prairies.   Castanea 67 1-12

Borak R. S et al 2017
Restored tall grass prairies have reduced phylogenetic diversity compared with remnants
Journal of Applied Ecology 54 1080 – 1090

John Lawson, 1674-1711 A New Voyage to Carolina; Containing the Exact Description and Natural History of That Country: Together with the Present State Thereof. And a Journal of a Thousand Miles, Travel'd Thro' Several Nations of Indians. Giving a Particular Account of Their Customs, Manners, &c. (unc.edu)

Juras, P. (1997); The pre-settlement of Piedmont Savanna, MS thesis University of Georgia

Fecher T. (2008); The Trading Paths of North Carolina 2008 J of Backcountry Studies 

Renwick, A (2015); Riches in the Ditches, Flora 2015 pp 6-7

Renwick, A (2017); Recreating a Vanishing Piedmont Landscape at Sarah P. Duke Gardens, The Trillium Volume 27, Issue 2 pg. 1-3