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Eastern Highland Rim Hardpan Prairie

Synonyms

Eastern Highland Rim Prairie & Barrens Ecological System (NatureServe 2015)

Distribution

Southeastern Middle Tennessee where known from a single example at May Prairie State Natural Area, Coffee County, Tennessee.

Vegetation Description

Grasses and forbs, with few tree saplings and shrubs, dominate this small patch community that ranges in height from 0 – 2.00 m. Vascular plant diversity and species richness are high.

Physical Characterization

This community occurs in the Undissected Eastern Highland Rim ecoregion (Estes & Fleming 2015) at an elevation of 329 m (1,080 ft). It is associated with flats with 0-1% slopes. The geology is Paleozoic Mississippian-aged St. Louis and Warsaw limestones. 

The soils associated with this community belong to the Guthrie soil series and are associated with talf (plains or flats) landforms. They are wetland soils classified as thermic Fluvaquentic Endoaquepts. They are derived from loess and/or loamy alluvium and soils of the Guthrie series range from silt loam in the upper horizons to silty clay loam at lower depths. A clay fragipan is present at about 18-40 inches below the surface rendering these sites poorly drained and may experience ponding during wet seasons. Soils are often saturated in winter and spring but often become dessicated in summer and fall. Soil pH ranges from strongly to very strongly acid.

Soil series involved:

  • Gu - Guthrie Silt Loam

Natural Processes

The hydroxeric soils underlain by a hardpan, which restrict root development of trees, combined with the historically frequent recurrence of fires favored the establishment and maintenance of grassland vegetation. Fire return intervals of 3.2 years have documented for the 1700s through mid-1800s by Stambaugh et al. (2016) from Arnold Airforce Base, Coffee Co., TN, approximately 2-3 km to the west. This frequency of fire would have maintained extensive prairie and savanna in the EHR. 

Following widespread fire suppression in the mid- to late-1800s, these grasslands would have been maintained by Euroamerican livestock (cattle, horses, sheep) grazing as well as fires set by farmers in the 1800s through mid-1900s. Mowing and in some areas, livestock grazing, has become the primary means of keeping these sites open. The single known hardpan prairie at May Prairie is likely a virgin prairie that has somehow escaped destruction.

Dominant Plants

Herbaceous Layer: Andropogon gerardii (big bluestem), Aristida purpurascens (____ three-awn-grass), Dichanthelium ensifolium (_____), Dichanthelium scoparium (___), Eupatorium hyssopifolium (hyssop-leaved thoroughwort), Helenium autumnale (autumn sneezeweed), Panicum virgatum (switchgrass), Schizachyrium scoparium (little bluestem)

Characteristic Plants

Herbaceous Layer: 

Restricted or Noteworthy Plants

Agalinis decemloba (_____), A. oligophylla (_____), Baptisia aberrans (____), Carex pellita (____), Castilleja coccinea (Indian paintbrush), Dichanthelium ensifolium (____), Drosera brevifolia (dwarf sundew), Eryngium integrifolium (blue-flower coyote-thistle), Hypericum denticulatum (____), Packera crawfordii (Crawford's ragwort), Pedicularis lanceolata (swamp lousewort), Platanthera nivea (snowy orchid), Proserpinaca pectinata (___)Prunus pumila (sand cherry), Ranunculus laxicaulis (_____), Scleria ciliata (____), S. verticillata (___ nutrush), Silphium mohrii (Mohr's rosinweed), S. pinnatifidum (cutleaf prairie dock), Triantha racemosa (coastal false asphodel), Utricularia cornuta (____), U. subulata (____)

Invasive Species
Arthraxon hispidus (hairy joint grass) is expanding from a recent stream restoration project at the edge of the prairie and may spread into the prairie with time

Community Variation and Subtypes
This community matches the Highland Rim Wet-Mesic Prairie (see below), which is a G1 community originally described from May Prairie, Coffee Co., TN. There are probably 1-2 other undescribed hardpan grassland associations at May Prairie that probably correspond to depth of the fragipan and degree of ponding. Areas with more ponding and presumably a shallower fragipan tend to support shorter, sparser vegetation with fewer bunchgrasses and more small exposures of bare ground. Other areas presumably with deeper soils and less ponding tend to support rather dense mid- to tallgrass prairie. Within this taller, denser type, there may be two associations that separate based on moisture gradients, with a drier subtype and a wet-mesic subtype.

CEGL004006 Andropogon gerardii - Schizachyrium scoparium - Dichanthelium scoparium - Rhynchospora glomerata Herbaceous Vegetation G1
Highland Rim Wet-Mesic Prairie
Big Bluestem - Little Bluestem - Broom Witchgrass - Clustered Beaksedge Herbaceous Vegetation


Associated Natural Communities

Eastern Highland Rim Hydroxeric Flatwoods, Eastern Highland Rim Dry Flatwoods

Similar Communities

This community is globally unique and known only from May Prairie, Coffee Co., TN. The Grand Prairie in eastern Arkansas is similar and they share several rare species in common. 

Presettlement Distribution and Size

This small-patch wet grassland is part of once was one of the largest grassland systems in the Mid-South U.S. The larger prairie/savanna matrix probably covered about ____ acres at European settlement. No doubt these small hardpan prairies have always been a minor component but just how much acreage once existed cannot be known. It is likely that >99% of original sites has been eliminated.

The Eastern Highland Rim grasslands once extended from at least Wayne Co., KY (but probably as far north as Lincoln Co., KY) south through TN into north Alabama. These grasslands were documented as early as 1769 by the longhunters on their first expedition into Middle Tennessee. On a journey from Price's Meadow (Wayne Co., KY) south to about the area where the Caney Fork River crosses the EHR, they described the EHR as "...covered with high grass which seemed inexhaustible" (Haywood ___). From the EHR of north Alabama, ___ (___) described the area just south of the Tennessee River as "____."  By the time the first naturalists began to describe the landscape of the EHR in any detail much of it had already been greatly altered. [provide early quotes of former status]. Augustine Gattinger, Tennessee's foremost botanist in the 1800s, spent much time in the "Barrens" of Coffee Co.  

Present Status

This single known representative is protected and actively managed. Should other sites be found outside May Prairie they should be considered highly endangered.

Representative Sites

Coffee Co.: May Prairie State Natural Area (35.450085, -86.030992)


Threats

There are no immediate threats to the single known example of this community.

Management Considerations

Prescribed fire is used to manage this community at the frequency of every __-__ years. Burns are typicallly conducted in _____. [discuss management of red maple saplings] 

Future Research Needs

In spite of being one of the best known and most botanized sites in Tennessee, this community and May Prairie Natural Area in general continues to yield exciting discoveries. In 2008, a new species of Symphyotrichum (aster) was discovered that is presently considered to be an undescribed single-site endemic. Packera crawfordii was documented from May Prairie for the first time in April 2012. A full systematic floristic inventory is needed for this community.

Previous Studies

The soils associated with this community belong to the Guthrie soil series and are associated with talf (plains or flats) landforms. They are wetland soils classified as thermic Fluvaquentic Endoaquepts. They are derived from loess and/or loamy alluvium and soils of the Guthrie series range from silt loam in the upper horizons to silty clay loam at lower depths. A clay fragipan is present at about 18-40 inches below the surface rendering these sites poorly drained and may experience ponding during wet seasons. Soils are often saturated in winter and spring but often become dessicated in summer and fall. Soil pH ranges from strongly to very strongly acid.

Soil series involved:

Natural Processes

The hydroxeric soils underlain by a hardpan, which restrict root development of trees, combined with the historically frequent recurrence of fires favored the establishment and maintenance of grassland vegetation. Fire return intervals of 3.2 years have documented for the 1700s through mid-1800s by Stambaugh et al. (2016) from Arnold Airforce Base, Coffee Co., TN, approximately 2-3 km to the west. This frequency of fire would have maintained extensive prairie and savanna in the EHR. 

Following widespread fire suppression in the mid- to late-1800s, these grasslands would have been maintained by Euroamerican livestock (cattle, horses, sheep) grazing as well as fires set by farmers in the 1800s through mid-1900s. Mowing and in some areas, livestock grazing, has become the primary means of keeping these sites open. The single known hardpan prairie at May Prairie is likely a virgin prairie that has somehow escaped destruction.

Dominant Plants

Herbaceous Layer: Andropogon gerardii (big bluestem), Aristida purpurascens (____ three-awn-grass), Dichanthelium ensifolium (_____), Dichanthelium scoparium (___), Eupatorium hyssopifolium (hyssop-leaved thoroughwort), Helenium autumnale (autumn sneezeweed), Panicum virgatum (switchgrass), Schizachyrium scoparium (little bluestem)

Characteristic Plants

Herbaceous Layer: 

Restricted or Noteworthy Plants

Agalinis decemloba (_____), A. oligophylla (_____), Baptisia aberrans (____), Carex pellita (____), Castilleja coccinea (Indian paintbrush), Dichanthelium ensifolium (____), Drosera brevifolia (dwarf sundew), Eryngium integrifolium (blue-flower coyote-thistle), Hypericum denticulatum (____), Packera crawfordii (Crawford's ragwort), Pedicularis lanceolata (swamp lousewort), Platanthera nivea (snowy orchid), Proserpinaca pectinata (___)Prunus pumila (sand cherry), Ranunculus laxicaulis (_____), Scleria ciliata (____), S. verticillata (___ nutrush), Silphium mohrii (Mohr's rosinweed), S. pinnatifidum (cutleaf prairie dock), Triantha racemosa (coastal false asphodel), Utricularia cornuta (____), U. subulata (____)

Invasive Species
Arthraxon hispidus (hairy joint grass) is expanding from a recent stream restoration project at the edge of the prairie and may spread into the prairie with time

Community Variation and Subtypes
This community matches the Highland Rim Wet-Mesic Prairie (see below), which is a G1 community originally described from May Prairie, Coffee Co., TN. There are probably 1-2 other undescribed hardpan grassland associations at May Prairie that probably correspond to depth of the fragipan and degree of ponding. Areas with more ponding and presumably a shallower fragipan tend to support shorter, sparser vegetation with fewer bunchgrasses and more small exposures of bare ground. Other areas presumably with deeper soils and less ponding tend to support rather dense mid- to tallgrass prairie. Within this taller, denser type, there may be two associations that separate based on moisture gradients, with a drier subtype and a wet-mesic subtype.

CEGL004006 Andropogon gerardii - Schizachyrium scoparium - Dichanthelium scoparium - Rhynchospora glomerata Herbaceous Vegetation G1
Highland Rim Wet-Mesic Prairie
Big Bluestem - Little Bluestem - Broom Witchgrass - Clustered Beaksedge Herbaceous Vegetation


Associated Natural Communities

Eastern Highland Rim Hydroxeric Flatwoods, Eastern Highland Rim Dry Flatwoods

Similar Communities

This community is globally unique and known only from May Prairie, Coffee Co., TN. The Grand Prairie in eastern Arkansas is similar and they share several rare species in common. 

Presettlement Distribution and Size

This small-patch wet grassland is part of once was one of the largest grassland systems in the Mid-South U.S. The larger prairie/savanna matrix probably covered about ____ acres at European settlement. No doubt these small hardpan prairies have always been a minor component but just how much acreage once existed cannot be known. It is likely that >99% of original sites has been eliminated.

The Eastern Highland Rim grasslands once extended from at least Wayne Co., KY (but probably as far north as Lincoln Co., KY) south through TN into north Alabama. These grasslands were documented as early as 1769 by the longhunters on their first expedition into Middle Tennessee. On a journey from Price's Meadow (Wayne Co., KY) south to about the area where the Caney Fork River crosses the EHR, they described the EHR as "...covered with high grass which seemed inexhaustible" (Haywood ___). From the EHR of north Alabama, ___ (___) described the area just south of the Tennessee River as "____."  By the time the first naturalists began to describe the landscape of the EHR in any detail much of it had already been greatly altered. [provide early quotes of former status]. Augustine Gattinger, Tennessee's foremost botanist in the 1800s, spent much time in the "Barrens" of Coffee Co.  

Present Status

This single known representative is protected and actively managed. Should other sites be found outside May Prairie they should be considered highly endangered.

Representative Sites

Coffee Co.: May Prairie State Natural Area (35.450085, -86.030992)


Threats

There are no immediate threats to the single known example of this community.

Management Considerations

Prescribed fire is used to manage this community at the frequency of every __-__ years. Burns are typicallly conducted in _____. [discuss management of red maple saplings] 

Future Research Needs

In spite of being one of the best known and most botanized sites in Tennessee, this community and May Prairie Natural Area in general continues to yield exciting discoveries. In 2008, a new species of Symphyotrichum (aster) was discovered that is presently considered to be an undescribed single-site endemic. Packera crawfordii was documented from May Prairie for the first time in April 2012. A full systematic floristic inventory is needed for this community.

Previous Studies

This prairie community has been surveyed by many botanists through the years. 


References

DeSelm, H. R., and N. Murdock. 1993. Grass-dominated communities. Pages 87-141 in: W. H. Martin, S. G. Boyce, and A. C. Echternacht, editors. Biodiversity of the southeastern United States: Upland terrestrial communities. John Wiley and Sons, New York.

DeSelm, H.R., 1990. Flora and vegetation of some barrens of the eastern Highland Rim of Tennessee. Castanea, pp.187-206.

DeSelm, H.R., 1994. Tennessee barrens. Castanea, pp.214-225.

Geology available at Tennesse Spatial Data Server which can be found at http://www.tngis.org/geology.html which links to a USGS Water Resources Division site: http://water.usgs.gov/lookup/getspatial?geo250k Tennessee Spatial Data Server site notes: Thanks goes to Jim Julian for researching this improved geology layer from the Tennessee Division of Geology. **Note** - The Tennessee Division of Geology does not endorse this coverage, stating this version is still incomplete and not fit for distribution.Noss,

Haywood ___. 1823.

NatureServe. 2014. NatureServe Explorer: An online encyclopedia of life [web application]. Version 7.1. NatureServe, Arlington, Virginia. Available http://explorer.natureserve.org. (Accessed: March 1, 2015).

Soil Survey Staff, Natural Resources Conservation Service, United States Department of Agriculture. Web Soil Survey. Available online at http://websoilsurvey.nrcs.usda.gov/. Accessed [02/25/2015].

Sorrie, B. and A.S. Weakley. 2001.

USNVC [United States National Vegetation Classification]. 2016. United States National Vegetation Classification Database, V2.0. Federal Geographic Data Committee, Vegetation Subcommittee, Washington DC. [usnvc.org] (accessed 27 Dec 2016)

Floristic Checklist 

List compiled by surveys by D. Estes


References

DeSelm, H. R., and N. Murdock. 1993. Grass-dominated communities. Pages 87-141 in: W. H. Martin, S. G. Boyce, and A. C. Echternacht, editors. Biodiversity of the southeastern United States: Upland terrestrial communities. John Wiley and Sons, New York.

DeSelm, H.R., 1990. Flora and vegetation of some barrens of the eastern Highland Rim of Tennessee.  Castanea , pp.187-206.

DeSelm, H.R., 1994. Tennessee barrens. Castanea, pp.214-225.

Geology available at Tennesse Spatial Data Server which can be found at http://www.tngis.org/geology.html which links to a USGS Water Resources Division site: http://water.usgs.gov/lookup/getspatial?geo250k Tennessee Spatial Data Server site notes: Thanks goes to Jim Julian for researching this improved geology layer from the Tennessee Division of Geology. **Note** - The Tennessee Division of Geology does not endorse this coverage, stating this version is still incomplete and not fit for distribution.Noss,

Haywood ___. 1823.

NatureServe. 2014. NatureServe Explorer: An online encyclopedia of life [web application]. Version 7.1. NatureServe, Arlington, Virginia. Available http://explorer.natureserve.org. (Accessed: March 1, 2015).

Soil Survey Staff, Natural Resources Conservation Service, United States Department of Agriculture. Web Soil Survey. Available online at http://websoilsurvey.nrcs.usda.gov/. Accessed [02/25/2015].

Sorrie, B. and A.S. Weakley. 2001.

USNVC [United States National Vegetation Classification]. 2016. United States National Vegetation Classification Database, V2.0. Federal Geographic Data Committee, Vegetation Subcommittee, Washington DC. [usnvc.org] (accessed 27 Dec 2016)

Floristic Checklist 

List compiled by surveys by D. Estes