Name:
Schizachyrium scoparium - Sorghastrum nutans Herbaceous Alliance
Reference:
Midwestern Ecology Working Group...
Description:
This alliance, comprising dry-mesic tallgrass vegetation and blackland prairies, is found in the central United States and southern Canada. The vegetation of stands of this alliance is characterized by moderate to dense cover of medium and tall grasses and a diverse mixture of forbs. Woody species are absent to rare but can be uncommon in some communities. The most abundant species across the range of this alliance are Bouteloua curtipendula, Schizachyrium scoparium, and Sorghastrum nutans. Other graminoids species common in parts of this alliance are Andropogon gerardii, Bouteloua hirsuta, Carex spp., Danthonia spicata, Hesperostipa spartea (= Stipa spartea), and Sporobolus heterolepis. In the far southern part of the alliance's range, associations can contain Andropogon glomeratus, Panicum virgatum, and Sporobolus clandestinus. Some of the many forbs which can be found in this alliance include Symphyotrichum ericoides (= Aster ericoides), Echinacea pallida, Helianthus spp., Hedyotis nigricans var. nigricans (in Illinois and Missouri), Lespedeza capitata (especially on sand), Lithospermum canescens, Clinopodium arkansanum (= Calamintha arkansana) (in Illinois), and Solidago nemoralis. In the Southeast, Ratibida pinnata or Baptisia australis var. minor may be found, as well as a variety of forbs with Coastal Plain affinities. Woody species that are found in stands of this alliance are those that can adapt to the dry to dry-mesic conditions, such as Acer rubrum and Juniperus virginiana.In the Southeast, this alliance includes a variety of relatively restricted communities which are rare and/or have been greatly reduced through land-use change. Many of these occur on distinctive soils or geologic formations, such as calcareous clays. This includes the Jackson Formation of Mississippi and Louisiana; the Cook Mountain Formation, Fleming Formation, and Morse Clays of Louisiana; the Demopolis and related formations of the Alabama Black Belt; as well as blackland prairies on Alfisols, Mollisols, and Vertisols in Texas, and isolated occurrences on the Catahoula Formation in eastern Texas. This alliance also occurs in the Coosa River valley of northwestern Georgia and northeastern Alabama and the Arbuckle Mountains of Oklahoma. This alliance includes remnant prairie-like vegetation occupying small areas (<1 acre) of mafic substrates in the Southern Blue Ridge plateau underlain by magnesium-rich bedrock; this vegetation is disjunct from the principal distribution of this alliance. Fire presumably played an important ecological role in maintaining natural stands of this vegetation in the presettlement landscape. Threats to these communities include fire suppression, livestock grazing, and damage by feral hogs and by vehicles. Most stands of this alliance are found on gentle to moderately steep slopes, although stands on flat plains can occur (Curtis 1959, Nelson 1985). The most prevalent slope aspects are south or west. Soils range from shallow to deep and are well-drained to excessively well-drained (White and Madany 1978, Chapman 1984). Most are loams or sands, but some can be gravel or clay. These soils are formed from eolian or alluvial sand, limestone, dolomite, sandstone, glacial till, glacial outwash, chert, loess, or shale.
Accession Code:
VB.CC.18805.SCHIZACHYRIUMSC
Plot-observations of this Community Concept:
0
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