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CEGL002391 Quercus stellata - Quercus marilandica / Schizachyrium scoparium Wooded Grassland
Type Concept Sentence: No Data Available
Common (Translated Scientific) Name: Post Oak - Blackjack Oak / Little Bluestem Wooded Grassland
Colloquial Name: Central Post Oak Dry Barrens
Hierarchy Level: Association
Type Concept: This open post oak barrens community is found in the Interior Highlands region of the central United States. Stands occur on shallow, somewhat excessively drained soil over bedrock (commonly sandstone or sandy/gravelly substrates) or on dry, exposed slopes. Soils are infertile, circumneutral to slightly acidic, and moderately well-drained to rapidly drained. Large boulders and pavements of exposed sandstone may occur. Stunted, xerophytic oaks grow above a sparse layer of grasses less than 1 m tall. Tree canopy species include Quercus marilandica, Quercus stellata, Quercus falcata, Quercus alba, and Quercus velutina. Shrubby areas, often containing Vaccinium arboreum, may be present. The herbaceous layer is composed of Carex pensylvanica, Danthonia spicata, Koeleria macrantha, and Schizachyrium scoparium. Other characteristic species include Clitoria mariana, Liatris squarrosa, and Solidago juncea.
Diagnostic Characteristics: No Data Available
Rationale for Nominal Species or Physiognomic Features: No Data Available
Classification Comments: This community is found in the Shawnee Hills and widely separated areas along major stream valleys in Illinois. It also occurs in Missouri, Indiana, and Arkansas, and possibly Kentucky, where it is associated with acid oak woodlands. In Indiana, the chert barrens are primarily tracked as ~Quercus stellata - Quercus marilandica / Schizachyrium scoparium - Silphium terebinthinaceum Wooded Grassland (CEGL005134)$$. This community is threatened by lack of fire which has resulted in canopy closure, denser undergrowth, and a loss of ground cover. This "savanna" type is closely allied to ~Quercus stellata - Quercus marilandica - Quercus velutina - Carya texana / Schizachyrium scoparium Woodland (CEGL002149)$$. Together with the woodlands, these communities are often referred to as "barrens" (Hutchison 1994).
Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: The amount and size of bedrock on the surface dramatically affects the vegetative community. Tree canopy 5-20 m tall, tall shrub 0.5-5 m, and graminoid layer 0-2 m.
Floristics: This community consists of a patchy, open layer of stunted, xerophytic oaks and a patchy layer of grasses less than 1 m tall. The herbaceous layer is composed of Danthonia spicata, Carex pensylvanica, Koeleria macrantha, and Schizachyrium scoparium. Tree canopy species include Quercus marilandica, Quercus stellata, Quercus falcata, Quercus alba, and Quercus velutina. Shrubby areas, often containing Vaccinium arboreum, may be present. Other characteristic species include Clitoria mariana, Liatris squarrosa, and Solidago juncea (TNC 1995a). Exotics which may be invasive include Securigera varia (= Coronilla varia), Elaeagnus umbellata, Populus alba, and Rosa multiflora. The type, size, and percent cover of bedrock within the community has an important effect on species composition. Substrate availability also greatly affects canopy cover, which is extremely variable throughout the range of this natural community. Juniperus virginiana can become a serious invasive within this community, especially if fires are suppressed. Herbaceous diversity can vary considerably with substrate and geographic location.
Dynamics: Natural disturbances include damage from drought, freeze/thaw, icestorms, lightning, wind, insects, and disease (bacteria, fungi). These open stands, as well as associated woodlands, can be managed by fire to retain their openness. Fires may historically have burned every 5-10 years (Nelson 1985). Summer heat and drought greatly influence vegetative growth and recruitment within this community (Fralish 1988). Periods of freezing and thawing encourage downslope subsidence of soil material and affects substrate availability. These climatic extremes coupled with edaphic characteristics, which include thin, stony, rapidly drained soils and exposed bedrock, favor this open vegetation. Where unnatural fire suppression has occurred, canopy closure may exceed that commonly associated with a sparse woodland. Edaphic factors are largely responsible for successional stability of this community, but natural, low-intensity, infrequent fires may also be important for maintaining this wooded herbaceous community (Fralish et al. 1991, Robertson and Heikens 1994).
Environmental Description: This community is found on thin, infertile soils which are very rapidly drained and strewn with rock fragments, stones, boulders, and bedrock pavements. Soils are often moderately to highly acidic (pH <6.5) and low in organic matter. Soils are predominantly stony and rocky, developed from windblown loess and weathered sandstone. Southern and western aspects have very high temperatures during the summer as well as frequent periods of freezing and thawing during the winter, which contributes to downslope migration of soil materials and associated rock and organic debris. Droughty conditions prevail throughout most of the year. Soils are subject to erosion, and patches of bare ground are not uncommon. The substrate restricts tree growth and limits herbaceous diversity. In the Cretaceous Hills region of Illinois, the bedrock is sedimentary, formed by the accumulation of minerals, rock debris, and/or organic matter from weathering, erosion, and deposition of rocks present during the Paleozoic Era. Bedrock, which is most frequently sandstone, has a layered appearance due to the accumulation and compression processes. Soil pH is slightly to moderately acidic when underlain or mixed with sandstone, chert, or igneous material (TNC 1995a).
Soils of this open woodland (barrens) are extremely stony and rocky or areas of soils interspersed with many boulders, rock outcrops, and vertical bluffs. Exposed rock is dominant. Conditions vary from site to site and may contain long, narrow sandstone bluffs to oblong areas strewn with boulders and small rock outcrops. Areas with many stones and flags are also common. Intervening soils may be from 10-150 cm thick over bedrock. Surface layers are silt loam or stony silt loam overlying subsurface layers which can be silty clay loam or stony loam. Silty clay occurs where shale is present and crops out on the surface. Soils information was collected from cores and pits and county soils map. Primarily Ultisols with a thermic temperature regime and udic moisture regime. Soils are very stony and rocky, consisting of windblown loess and weathered parent material.
Bedrock is sedimentary, formed by the accumulation of sediments from weathering, erosion, and deposition of rocks present during the Paleozoic Era. These rocks are made of minerals, rock debris, and/or organic matter and have a layered appearance due to accumulation and compression processes. Sandstone is the most frequently encountered bedrock in this forest. Rock color is variable, but most often gray, brown, yellowish, and/or reddish, determined by the type, amount, and color of cementing agents. The degree of hardness is variable but is very hard if cemented by silica. Erosion-resistant sandstone forms ridges in the landscape between pockets of softer rocks. Soil pH is slightly to moderately acidic when underlain or mixed with sandstone, chert, or igneous material.
Environmental variables associated with this open woodland include thin, infertile soils which are very rapidly drained and strewn with rock fragments, stones, boulders, and bedrock pavements. Soils are often moderately to highly acidic (pH <6.5). South to west aspects have high summer heat as well as frequent periods of freezing and thawing, which contribute to downslope migration of soil materials and associated rock and organic debris. The open canopy permits a lot of light to penetrate to the ground layer.
Soils of this open woodland (barrens) are extremely stony and rocky or areas of soils interspersed with many boulders, rock outcrops, and vertical bluffs. Exposed rock is dominant. Conditions vary from site to site and may contain long, narrow sandstone bluffs to oblong areas strewn with boulders and small rock outcrops. Areas with many stones and flags are also common. Intervening soils may be from 10-150 cm thick over bedrock. Surface layers are silt loam or stony silt loam overlying subsurface layers which can be silty clay loam or stony loam. Silty clay occurs where shale is present and crops out on the surface. Soils information was collected from cores and pits and county soils map. Primarily Ultisols with a thermic temperature regime and udic moisture regime. Soils are very stony and rocky, consisting of windblown loess and weathered parent material.
Bedrock is sedimentary, formed by the accumulation of sediments from weathering, erosion, and deposition of rocks present during the Paleozoic Era. These rocks are made of minerals, rock debris, and/or organic matter and have a layered appearance due to accumulation and compression processes. Sandstone is the most frequently encountered bedrock in this forest. Rock color is variable, but most often gray, brown, yellowish, and/or reddish, determined by the type, amount, and color of cementing agents. The degree of hardness is variable but is very hard if cemented by silica. Erosion-resistant sandstone forms ridges in the landscape between pockets of softer rocks. Soil pH is slightly to moderately acidic when underlain or mixed with sandstone, chert, or igneous material.
Environmental variables associated with this open woodland include thin, infertile soils which are very rapidly drained and strewn with rock fragments, stones, boulders, and bedrock pavements. Soils are often moderately to highly acidic (pH <6.5). South to west aspects have high summer heat as well as frequent periods of freezing and thawing, which contribute to downslope migration of soil materials and associated rock and organic debris. The open canopy permits a lot of light to penetrate to the ground layer.
Geographic Range: This open post oak barrens community is found in the Interior Highlands region of the United States, ranging from the Ozark region of Missouri and Arkansas, east to Illinois and Indiana and possibly Kentucky.
Nations: US
States/Provinces: AR, IL, IN, KY?, MO
Plot Analysis Summary:
http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.688186
Confidence Level: Low - Poorly Documented
Confidence Level Comments: No Data Available
Grank: G2G3
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.Nc Eastern North American Grassland & Shrubland Division | D024 | 2.B.2.Nc |
| Macrogroup | 2.B.2.Nc.2 Little Bluestem - Silky Oatgrass Acidic Scrub & Grassland Macrogroup | M509 | 2.B.2.Nc.2 |
| Group | 2.B.2.Nc.2.b Little Bluestem - Silky Oatgrass Acidic Glade & Barrens Group | G178 | 2.B.2.Nc.2.b |
| Alliance | A1920 Post Oak - Blackjack Oak / Little Bluestem Interior Acidic Bedrock Scrub Alliance | A1920 | 2.B.2.Nc.2.b |
| Association | CEGL002391 Post Oak - Blackjack Oak / Little Bluestem Wooded Grassland | CEGL002391 | 2.B.2.Nc.2.b |
Concept Lineage: This community was a Cretaceous Hills only type, but after regional review, is considered to be part of this more broad-ranging post oak dry barrens type.
Predecessors: No Data Available
Obsolete Names: No Data Available
Obsolete Parents: No Data Available
Synonomy: = Quercus stellata - Quercus marilandica / Schizachyrium scoparium Wooded Herbaceous Vegetation (Faber-Langendoen 2001)
= Quercus stellata - Quercus marilandica / Schizachyrium scoparium Wooded Herbaceous Vegetation (TNC 1995a)
? Acid (Chert, Igneous, Sandstone) Savannah (Nelson 1985)
>< Chert Savanna (Nelson 1985)
< Eastern Broadleaf Forests: 100: Oak-Hickory Forest (Quercus-Carya) (Küchler 1964)
< Eastern Broadleaf and Needleleaf Forests: 111: Oak-Hickory-Pine Forest (Quercus-Carya-Pinus) (Küchler 1964)
< IB4c. Western Post Oak - Blackjack Oak Woodland (Allard 1990)
>< Igneous Savanna (Nelson 1985)
< Post Oak - Blackjack Oak: 40 (Eyre 1980)
>< Sandstone Savanna (Nelson 1985)
= Quercus stellata - Quercus marilandica / Schizachyrium scoparium Wooded Herbaceous Vegetation (TNC 1995a)
? Acid (Chert, Igneous, Sandstone) Savannah (Nelson 1985)
>< Chert Savanna (Nelson 1985)
< Eastern Broadleaf Forests: 100: Oak-Hickory Forest (Quercus-Carya) (Küchler 1964)
< Eastern Broadleaf and Needleleaf Forests: 111: Oak-Hickory-Pine Forest (Quercus-Carya-Pinus) (Küchler 1964)
< IB4c. Western Post Oak - Blackjack Oak Woodland (Allard 1990)
>< Igneous Savanna (Nelson 1985)
< Post Oak - Blackjack Oak: 40 (Eyre 1980)
>< Sandstone Savanna (Nelson 1985)
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