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A2074 Fraxinus americana - Quercus stellata / Carex pensylvanica Appalachian Mafic-Circumneutral Scrub Alliance

Type Concept Sentence: This Appalachian shale barrens vegetation is dominated by graminoids such as Andropogon sp., Carex pensylvanica, Danthonia spicata, Piptochaetium avenaceum, Schizachyrium scoparium, and Sporobolus compositus, with some scattered Juniperus virginiana var. virginiana, Quercus montana, Quercus stellata, and/or Quercus velutina in the open to sparse canopy.


Common (Translated Scientific) Name: White Ash - Post Oak / Pennsylvania Sedge Appalachian Mafic-Circumneutral Scrub Alliance

Colloquial Name: Appalachian-Piedmont Mafic-Calcareous Barrens.

Hierarchy Level:  Alliance

Type Concept: This Appalachian shale barrens vegetation is dominated by native graminoids such as Andropogon sp., Carex pensylvanica, Danthonia spicata, Piptochaetium avenaceum, Schizachyrium scoparium, and Sporobolus compositus, with some scattered Juniperus virginiana var. virginiana, Quercus montana, Quercus stellata, and/or Quercus velutina in the open to sparse canopy. This alliance occurs on shale and other geologic substrates with high available base status. These substrates include shales, calcareous shales, calcareous Silurian sandstones, metabasalt (greenstone), diabase, charnockite, amphibolite, metasiltstone and phyllite. This vegetation is found in the Appalachian region of the eastern United States. The physiognomy is generally maintained in a relatively open condition by a combination of dry thin soils and management practices. The physiognomy may vary from entirely herbaceous to sparse scrub or woodland.

Diagnostic Characteristics: Typical scattered trees include Fraxinus americana, Quercus stellata, and Juniperus virginiana. Carex pensylvanica is a dominant graminoid which occurs in these Appalachian barrens on mafic and other circumneutral substrates.

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: The inclusion of ~(Quercus stellata) / Schizachyrium scoparium - Packera plattensis - Parthenium auriculatum - Phemeranthus piedmontanus Wooded Grassland (CEGL006084)$$ here is appropriate. It is ultramafic and somewhat different from simply mafic associations. The old alliance of CEGL006084, (Pinus rigida) / Schizachyrium scoparium Wooded Herbaceous Alliance (A.1921), is not so different from former (Quercus stellata, Quercus marilandica) / Schizachyrium scoparium Wooded Herbaceous Alliance (A.1920). G. Fleming: In addition, there is a North Carolina "Diabase glade," ~Sporobolus vaginiflorus var. ozarkanus - Diodia teres - Croton michauxii var. ellipticus - Ruellia humilis Grassland (CEGL004276)$$, that may be better described (in its natural state) as a barrens. Associate Editor (Orie Loucks) made the following comment regarding the alliances in ~Appalachian Mafic Glade Group (G180)$$: "Seems like a lot of splitting of the group into distinct alliances. Too much focus on a specialized type, at association and alliance level? OK for now."

Similar NVC Types: No Data Available
note: No Data Available

Physiognomy and Structure: The physiognomy is maintained in an open condition by a combination of edaphic factors (droughty thin soils and shifting fragments of sedimentary rock) combined with management, such as thinning of trees, bush-hogging and prescribed fire. The physiognomy may vary from entirely herbaceous to sparse scrub or woodland. Examples exhibit a mixed physiognomy and may occur as a patch-mosaic of lichen and moss mats, herbs, and shrubs or stunted trees. A variety of deciduous and evergreen trees may be present, but less than 10 m tall. Canopy closure is usually less than 30%, and patchy, with herbaceous openings.

Floristics: Typical stands of this vegetation contain scattered Juniperus virginiana var. virginiana, Quercus montana (= Quercus prinus), Quercus stellata, and/or Quercus velutina in the open to sparse canopy, with Andropogon sp., Carex pensylvanica, Danthonia spicata, Piptochaetium avenaceum, Schizachyrium scoparium, and Sporobolus compositus as possible dominant graminoids. Some other characteristic plants include Cheilanthes lanosa, Deschampsia flexuosa, Elymus hystrix (= Hystrix patula), Helianthus divaricatus, Phacelia dubia, Phlox subulata, Polygonatum biflorum, Polygonum scandens var. cristatum, Pycnanthemum incanum, Silene antirrhina, Tradescantia virginiana, Triodanis perfoliata, Woodsia obtusa, and others. Other herbs include Acalypha sp., Agalinis purpurea, Asclepias verticillata, Cheilanthes tomentosa, Clitoria mariana, Coreopsis major, Croton willdenowii, Dichanthelium spp., Diodia virginiana, Erigeron strigosus, Euphorbia corollata, Fimbristylis sp., Galactia regularis, Hypericum gentianoides, Liatris microcephala, Liatris squarrosa, Manfreda virginica, Nuttallanthus canadensis, Salvia azurea, Scleria oligantha, Selaginella rupestris, Spiranthes lacera var. gracilis, and Stylosanthes biflora. In addition, Talinum teretifolium and Tragia urticifolia are characteristic herbs in some associations. The blue-green alga Nostoc commune may be present. Other scattered woody plants include Carya pallida, Celtis tenuifolia, Cercis canadensis, Fraxinus americana, Pinus echinata, Pinus virginiana, Prunus serotina, Ptelea trifoliata, Ulmus alata, and Vaccinium arboreum. Woody vines include Berchemia scandens and Cocculus carolinus. Shrubs include Asimina parviflora, Callicarpa americana, Chionanthus virginicus, Hypericum hypericoides ssp. hypericoides, Ptelea trifoliata, Rhus aromatica, Rhus copallinum, and Vaccinium arboreum.

Dynamics:  The rocky substrates supporting examples of this alliance may effectively limit the normal establishment and development of trees. Although periodic drought stress limits woody plants, the shrub Symphoricarpos orbiculatus has increased in one occurrence. Ruderal weeds such as Veronica arvensis, Barbarea vulgaris, and Verbascum thapsus can also become problematic, especially in wet years.

Environmental Description:  Examples may occur on rocky ridges, spur ridge crests, and exposed areas of bedrock throughout the range of the alliance. Stands are better developed and more persistent on the landscape on southerly to westerly aspects. Substrates include shales, calcareous shales, calcareous Silurian sandstones, metabasalt (greenstone), diabase, charnockite, amphibolite, metasiltstone and phyllite. Rocky outcrops on which this vegetation may occur effectively limit the normal establishment and development of trees.

Geographic Range: This alliance is currently known from the Appalachian region (including the Cumberland Plateau, Ridge and Valley, and Piedmont, as well as the Blue Ridge) of the eastern United States. This includes calcareous regions in western Connecticut, eastern Pennsylvania, northeastern New Jersey, the Central Appalachians and Ridge and Valley of Maryland, Pennsylvania, Virginia, and West Virginia, as well as the Piedmont of Virginia and Georgia. A few examples may occur in New York.

Nations: US

States/Provinces:  GA, VA




Confidence Level: Moderate

Confidence Level Comments: No Data Available

Grank: GNR

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.1 Catawba Rosebay / Michaux''s Saxifrage - Flattened Oatgrass Felsic & Mafic Scrub & Grassland Macrogroup M506 2.B.2.Nc.1
Group 2.B.2.Nc.1.c Little Bluestem - Balsam Groundsel - Prairie Groundsel Appalachian Mafic Glade Group G180 2.B.2.Nc.1.c
Alliance A2074 White Ash - Post Oak / Pennsylvania Sedge Appalachian Mafic-Circumneutral Scrub Alliance A2074 2.B.2.Nc.1.c
Association CEGL003683 White Ash - Pignut Hickory / Rock Muhly - Woodland Sunflower - Elmleaf Goldenrod Woodland CEGL003683 2.B.2.Nc.1.c
Association CEGL006037 Eastern Red-cedar - White Ash / Pennsylvania Sedge - Hairy Lipfern Open Woodland CEGL006037 2.B.2.Nc.1.c
Association CEGL006084 (Post Oak) / Little Bluestem - Prairie Groundsel - Glade Wild Quinine - Piedmont Fameflower Wooded Grassland CEGL006084 2.B.2.Nc.1.c
Association CEGL006215 Post Oak / Little Bluestem - Big Bluestem - Narrowleaf Mountainmint - Balsam Groundsel Wooded Grassland CEGL006215 2.B.2.Nc.1.c
Association CEGL006294 White Ash - Eastern Red-cedar / Eastern Prickly-pear - (Quill Fameflower, Piedmont Fameflower) Outcrop Barrens CEGL006294 2.B.2.Nc.1.c
Association CEGL008485 Eastern Red-cedar - Dwarf Hackberry - Post Oak / Tall Dropseed - Quill Fameflower Wooded Grassland CEGL008485 2.B.2.Nc.1.c
Association CEGL008529 White Ash / Common Ninebark / Pennsylvania Sedge - Nodding Onion - (Small-flower Phacelia) Wooded Grassland CEGL008529 2.B.2.Nc.1.c

Concept Lineage: This alliance (A2074) includes all of the former A.3014, the one association from A.1921, plus some from A.1919 and a few from A.1920; most of A.1919 are Ozark/ILP or WGC plain, so they will have to go somewhere else... TBD]. There will be 2 additional alliances, the "Interior Circumneutral Barrens" from KY/TN to AR/OK/MO; and an equivalent Acidic one. A.3014, A.1921, A.1919, A.1920, in part

Predecessors: No Data Available

Obsolete Names: No Data Available

Obsolete Parents: No Data Available

Synonomy: >< ID4g. Sandstone Prairie (Allard 1990)

Concept Author(s): M. Pyne, in Faber-Langendoen et al. (2013)

Author of Description: M. Pyne

Acknowledgements: No Data Available

Version Date: 09-26-14

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