Name:
Juniperus virginiana - Fraxinus americana / Carex pensylvanica - Cheilanthes lanosa Wooded Herbaceous Vegetation
Reference:
Eastern Ecology Working Group of...
Description:
This barrens community occurs on steep slopes with exposed outcrops of calcareous sedimentary, metasedimentary, and metamorphic rocks of the Central Appalachians. In the Ridge and Valley province, underlying bedrock includes calcareous shales of the Jennings, Hampshire, Martinsburg, and Brallier formations, and less commonly calcareous Silurian sandstones. Blue Ridge sites are underlain by Catoctin Formation metabasalt, amphibolite, and Harpers Formation metasiltstone and phyllite. Habitats are on steep, southeast - to southwest-facing slopes at elevations from 170 to 580 m (550-1900 feet). On sites underlain by shale, soils are thin but generally better developed than other shale-barren associations. Mafic-rock sites typically have high cover (about 50%) of exposed bedrock outcrops with some areas of shallow soil development. Sandstone sites generally consist of steep, continuous pavements with thin veneers and pockets of soil. Soils from all substrates have high calcium levels; those weathered from metabasalt and amphibolite also have high magnesium and manganese levels. A patchy overstory of stunted trees may ameliorate to some degree the otherwise xeric conditions imposed by exposure and slope. Canopy closure is usually less than 30%, occasionally higher, and tends to be patchy, with herbaceous openings. Shrubs are sparse at most known locations. The herbaceous layer forms 25-90% ground cover. The canopy is codominated by <i>Juniperus virginiana</i> and <i>Fraxinus americana</i>, with other associates including <i>Carya glabra, Quercus prinus, Quercus stellata, Celtis tenuifolia, Amelanchier arborea, Quercus rubra</i>, and <i>Pinus virginiana</i>. <i>Rhus aromatica</i> is a characteristic shrub. The herbaceous layer is very diverse. <i>Carex pensylvanica</i> is constant and dominant. <i>Danthonia spicata</i> is frequent but sparse. Other characteristic species include <i>Cheilanthes lanosa, Woodsia obtusa, Phacelia dubia, Deschampsia flexuosa, Solidago arguta var. harrisii (= Solidago harrisii), Schizachyrium scoparium, Phlox subulata, Silene antirrhina, Elymus hystrix (= Hystrix patula), Tradescantia virginiana, Helianthus divaricatus, Polygonum scandens var. cristatum, Polygonatum biflorum, Triodanis perfoliata, Pycnanthemum incanum, Allium cernuum</i>, and <i>Arenaria serpyllifolia</i>. This association is distinguished from other shale-barren types by its open physiognomy, occurrence on circumneutral to calcareous rock at low to moderate elevations, and the frequency of several characteristic herbs including <i>Cheilanthes lanosa, Phacelia dubia, Tradescantia virginiana</i>, and <i>Triodanis perfoliata</i>. In addition, <i>Fraxinus americana</i> and <i>Celtis tenuifolia</i> occur at a higher frequency in this association than in other shale-barren types.
Accession Code:
VB.CC.31035.CEGL006037
Plot-observations of this Community Concept:
0
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