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CEGL004021 Schizachyrium scoparium - Panicum flexile - Carex microdonta Grassland

Type Concept Sentence: No Data Available

Common (Translated Scientific) Name: Little Bluestem - Wiry Panicgrass - Little-tooth Sedge Grassland

Colloquial Name: Cook Mountain Prairie

Hierarchy Level:  Association

Type Concept: This upland herbaceous community of west-central Louisiana is characterized by treeless openings dominated by perennial grasses, composites, and legumes, with scattered clumps of shrubby vegetation. These floristically diverse areas are typically less than 1-8 hectares in size and occur within a forest matrix. This community occurs in west-central Louisiana and is associated with outcrops of the Cook Mountain Formation (Eocene). It is known from Winn, Sabine, and Natchitoches parishes. This herb-dominated community develops on soils derived from marly clays and chalk of marine origin. These soils are typically silty clay loams, clays, and silt loams that are well-drained, slowly permeable, and alkaline (pH 7.5-8.0). Subsurface clay layers have calcareous concretions and shrink-swell properties. This community occurs in a nearly level to gently rolling landscape, on ridgetops and gentle slopes that often border small streams. Moisture regimes are typically dry to dry-mesic. The combination of frequent fire, high soil pH and extreme physical soil properties are thought to be important in maintaining this community. Grasses include Schizachyrium scoparium, Andropogon glomeratus, Andropogon gerardii, Sporobolus spp., Setaria parviflora, Panicum flexile, Aristida spp., Paspalum floridanum, and Sorghastrum nutans. Other characteristic species include Carex cherokeensis, Stenaria nigricans, Dalea candida, Dalea purpurea, Ruellia humilis, Desmanthus illinoensis, Salvia azurea, Sporobolus vaginiflorus var. ozarkanus, Sporobolus compositus var. compositus, Helenium autumnale, Koeleria macrantha, Silphium laciniatum, Echinacea pallida.

Diagnostic Characteristics: No Data Available

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: This community has a limited distribution and most remaining sites are significantly disturbed. Feral pigs forage in these open areas, damaging the soil surface and herbaceous strata. In most prairie remnants, species composition has been altered by the introduction of exotic weedy species. This community occurs within calcareous forests that include species such as Quercus stellata, Quercus shumardii, Quercus alba, Fagus grandifolia, Fraxinus americana, Carya myristiciformis, Gleditsia triacanthos, Pinus taeda, and Pinus echinata. Historically these prairie openings were burned regularly (perhaps every 5-15 years) by lightning-generated fires. Similar communities occur on calcareous clays, associated with different geologic formations, in other parts of Louisiana. More study is needed to clearly define the vegetative distinctions among these communities, as well as with similar tallgrass communities in the southeastern and midwestern United States. This association is closely related to ~Schizachyrium scoparium - Sorghastrum nutans - Dalea purpurea - Silphium integrifolium Jackson Prairie Grassland (CEGL004020)$$; additional information is needed to clarify their relationship. Andropogon glomeratus is weedy and not diagnostic and has been replaced with the more diagnostic Panicum flexile. This type provisionally includes prairies on the Cane River Formation ("shell hill prairie"), documented from Natchitoches Parish, and possibly also in southern Bienville parishes, Louisiana; further information is needed to more definitively classify these prairie occurrences. This type also provisionally includes prairies likely occurring on the Wilcox Group in Louisiana.

Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: No Data Available

Floristics: This upland herbaceous community is characterized by treeless openings dominated by perennial grasses, composites, and legumes, with scattered clumps of shrubby vegetation. These floristically diverse areas are typically less than 1 to 8 hectares in size and occur within a forest matrix. Grasses include Schizachyrium scoparium, Andropogon glomeratus, Andropogon gerardii, Koeleria macrantha, Sporobolus vaginiflorus var. ozarkanus (= Sporobolus ozarkanus), Sporobolus compositus var. compositus, Setaria parviflora, Panicum flexile, Aristida spp., Paspalum floridanum, and Sorghastrum nutans. Other common species include Carex cherokeensis, Stenaria nigricans (= Hedyotis nigricans), Dalea candida, Dalea purpurea, Desmanthus illinoensis, Salvia azurea, Ambrosia psilostachya, Solidago spp., Silphium laciniatum, Helenium autumnale, Gaillardia aestivalis var. flavovirens, Echinacea pallida, Liatris spp., Neptunia lutea, Galactia spp., Desmanthus illinoensis, Delphinium carolinianum, Ruellia humilis, Callirhoe papaver, Asclepias tuberosa, Oenothera speciosa, Gaura longiflora, and Ranunculus sardous. Prominent woody species may include Crataegus spp., Berchemia scandens, Diospyros virginiana, Juniperus virginiana var. virginiana, Fraxinus americana, Ilex decidua, Cornus drummondii, Ulmus alata, Sideroxylon lanuginosum ssp. lanuginosum, Prunus mexicana, and Rubus spp. (Smith et al. 1989). Louisiana rare plant species reported from this community include Carex microdonta, Panicum flexile, Heliotropium tenellum, and Polytaenia nuttallii. Exotic plant species introduced through cattle grazing include Lonicera japonica, Schedonorus pratensis (= Festuca pratensis), Iva annua, Bromus arvensis (= Bromus japonicus), Pyrrhopappus carolinianus, among others (Smith et al. 1989).

Dynamics:  The combination of frequent fire, high soil pH, and extreme physical soil properties are thought to be important in maintaining this community. In the absence of fire, calciphilic woody species such as Fraxinus americana, Gleditsia triacanthos, Juniperus virginiana, and Crataegus spp. may invade and alter the physiognomy of this community to a shrubland, woodland, or forest.
Environmental Description:  This herbaceous-dominated community of west-central Louisiana develops on soils derived from marly clays and chalk of marine origin (Cook Mountain Formation; Eocene age). These soils are typically silty clay loams, clays, and silt loams that are well-drained, slowly permeable, and alkaline (pH 7.5-8.0). Subsurface clay layers have calcareous concretions and shrink-swell properties. This community occurs in a nearly level to gently rolling landscape, on ridgetops and gentle slopes that often border small streams. Elevations range from 46 to 76 m (150-250 feet) above mean sea level, and average annual rainfall is 127-140 cm (Smith et al. 1989). Moisture regimes are typically dry to dry-mesic. The combination of frequent fire, high soil pH, and extreme physical soil properties are thought to be important in maintaining this community.
Geographic Range: This community is restricted to west-central Louisiana and is known from Winn, Sabine, and Natchitoches parishes.

Nations: US

States/Provinces:  LA


Confidence Level: High

Confidence Level Comments: No Data Available
Grank: G1

Greasons: No Data Available
Type Name Database Code Classification Code
Class 2 Shrub & Herb Vegetation Class C02 2
Subclass 2.B Temperate & Boreal Grassland & Shrubland Subclass S18 2.B
Formation 2.B.2 Temperate Grassland & Shrubland Formation F012 2.B.2
Division 2.B.2.Nh Southeastern North American Grassland & Shrubland Division D102 2.B.2.Nh
Macrogroup 2.B.2.Nh.2 Southeastern Coastal Plain Patch Prairie Macrogroup M309 2.B.2.Nh.2
Group 2.B.2.Nh.2.a Little Bluestem - Switchgrass - Bushy Bluestem Patch Prairie Group G175 2.B.2.Nh.2.a
Alliance A3318 Little Bluestem - Indiangrass Coastal Plain Prairie Alliance A3318 2.B.2.Nh.2.a
Association CEGL004021 Little Bluestem - Wiry Panicgrass - Little-tooth Sedge Grassland CEGL004021 2.B.2.Nh.2.a
Concept Lineage: No Data Available

Predecessors: No Data Available

Obsolete Names: No Data Available

Obsolete Parents: No Data Available
Synonomy: < ID4e. Cook Mountain Calcareous Prairie (Allard 1990)
= Keiffer Calcareous Prairie (Smith et al. 1989)
? Keiffer Calcareous Prairie (Smith 1989)
Concept Author(s): Smith et al. (1989)

Author of Description: J.E. Mohan

Acknowledgements: No Data Available

Version Date: 02-19-95
  • Allard, D. J. 1990. Southeastern United States ecological community classification. Interim report, Version 1.2. The Nature Conservancy, Southeast Regional Office, Chapel Hill, NC. 96 pp.
  • LNHP [Louisiana Natural Heritage Program]. 2009. Natural communities of Louisiana. Louisiana Natural Heritage Program, Louisiana Department of Wildlife & Fisheries, Baton Rouge. 46 pp. [http://www.wlf.louisiana.gov/sites/default/files/pdf/page_wildlife/6776-Rare%20Natural%20Communities/LA_NAT_COM.pdf]
  • Martin, D. L., and L. M. Smith. 1991. A survey and description of the natural plant communities of the Kisatchie National Forest, Winn and Kisatchie districts. Louisiana Department of Wildlife and Fisheries, Baton Rouge, LA. 372 pp.
  • Smith, L. M., N. M. Gilmore, R. P. Martin, and G. D. Lester. 1989. Keiffer calcareous prairie/forest complex: A research report and preliminary management plan. Louisiana Department of Wildlife and Fisheries, Natural Heritage Program, Baton Rouge. 44 pp.
  • Smith, T. L. 1989. An overview of old-growth forests in Pennsylvania. Natural Areas Journal 9:40-44.
  • Southeastern Ecology Working Group of NatureServe. No date. International Ecological Classification Standard: International Vegetation Classification. Terrestrial Vegetation. NatureServe, Durham, NC.