Classification of Vegetation Communities of Maryland: First Iteration

II. WOODLAND
II.B.2.N.a. Cold-deciduous woodland
II.B.2.N.a.4. FRAXINUS AMERICANA - CARYA GLABRA - (JUNIPERUS VIRGINIANA) WOODLAND ALLIANCE
White Ash - Pignut Hickory - (Eastern Red-cedar) Woodland Alliance
 

Concept: Woodlands in this alliance have Fraxinus americana and Carya glabra as typical canopy dominants, although Juniperus virginiana, Quercus prinus, or other Carya spp. may have significant coverage in some associations. Some associations have a nearly closed or locally closed canopy, and could in some cases as readily be considered as forests, while others have an edaphically maintained woodland physiognomy. Other minor canopy species vary with geography, but may include Quercus rubra var. rubra, Pinus virginiana, Ulmus alata, Quercus stellata, Carya ovata, and Carya pallida. Subcanopy and shrub species are variable between associations, but can include Amelanchier sanguinea, Ceanothus americanus, Celtis tenuifolia, Cercis canadensis, Chionanthus virginicus, Crataegus sp., Hypericum prolificum, Juniperus virginiana var. virginiana, Lonicera flava, Ostrya virginiana, Philadelphus hirsutus, Physocarpus opulifolius, Ptelea trifoliata, Rhus aromatica var. aromatica, Rhus typhina, Rosa carolina, Spiraea betulifolia var. corymbosa, Symphoricarpos orbiculatus, Toxicodendron radicans, Vaccinium arboreum, Vaccinium pallidum, Vaccinium stamineum, Viburnum rafinesquianum (= var. rafinesquianum), and Viburnum rufidulum. Herbaceous species vary among associations, but species known from these woodlands include Allium cuthbertii, Andropogon gerardii, Andropogon gyrans, Andropogon ternarius, Anemone berlandieri, Anemone virginiana, Antennaria virginica, Aquilegia canadensis, Arabis canadensis, Arabis hirsuta var. pycnocarpa (= Arabis hirsuta var. adpressipilis), Arabis laevigata, Aristida purpurascens, Aristolochia serpentaria, Asclepias quadrifolia, Asplenium platyneuron, Symphyotrichum oblongifolium (= Aster oblongifolius), Symphyotrichum patens var. patens (= Aster patens var. patens), Campanula divaricata, Cardamine parviflora var. arenicola, Carex pensylvanica, Cheilanthes lanosa, Claytonia virginica, Coreopsis major, Coreopsis pubescens, Cunila origanoides, Danthonia compressa, Danthonia sericea, Danthonia spicata, Desmodium rotundifolium, Dichanthelium boscii, Dichanthelium scoparium, Dodecatheon meadia, Draba ramosissima, Elymus hystrix, Erigeron pulchellus, Helianthus divaricatus, Helianthus microcephalus, Houstonia longifolia, Hypericum gentianoides, Hypericum punctatum, Melica mutica, Muhlenbergia tenuiflora, Phacelia dubia, Phlox nivalis ssp. hentzii, Piptochaetium avenaceum, Polygala paucifolia, Polygonum tenue, Pycnanthemum incanum, Pycnanthemum montanum, Saxifraga michauxii, Schizachyrium scoparium, Sedum glaucophyllum, Selaginella rupestris, Packera millefolia (= Senecio millefolium), Packera obovata (= Senecio obovatus), Solidago arguta var. harrisii (= Solidago harrisii), Solidago juncea, Solidago nemoralis, Sorghastrum nutans, Tradescantia ohiensis, Verbesina occidentalis, Woodsia ilvensis, and Woodsia obtusa. These woodlands are often a physiognomic complex of woodland, grassland, and rock outcropping, often associated with granitic domes or rocky summits. Soils are circumneutral and derived from such base-rich rocks as greenstone, plagioclase-rich granite, hornblende gneiss, amphibole gneiss, limestones, or calcareous shales. Woodlands in this alliance are currently defined from 1000-3800 feet elevation in the southern and central Blue Ridge, the Ridge and Valley of Virginia, and the upper Piedmont of Georgia, North Carolina, and Virginia.

Comments: Most associations in this alliance are thought to be inherently rare because of their unusual geology and topographic position. Fleming (1999) discusses classification questions related to this alliance in Virginia and in the Nashville Basin of Tennessee: "In a study of woody vegetation in the Tennessee Central Basin, Crites and Clebsch (1986) found communities sorted along a topographic-moisture gradient. A 'Carya - Juniperus - Quercus Community' that may be similar to the Fraxinus americana - Carya ovata / Frangula caroliniana / Helianthus hirsutus Woodland (CEGL008458) (sensu Fleming 1999) was classified from subxeric upland habitats. The dominants of the Tennessee community (based on the importance values of woody species >2.5 cm dbh) were Fraxinus americana, either Carya ovata or Carya glabra (pignut hickory), and Juniperus virginiana. Fraxinus americana was considered a 'local successional species,' the densities of which were 'masking' the importance values of oaks (Crites and Clebsch 1986). Implicit (but not directly stated) in this assessment is the concept that Quercus muehlenbergii and other oaks represent a more advanced successional stage on the subxeric uplands. Of course, without data on shrub and herbaceous composition, it is impossible to accurately evaluate the similarity of the Virginia and Tennessee communities" (Fleming 1999). In relation to the possible presence of this alliance in the Central Basin of Tennessee, see the Fraxinus quadrangulata - (Juniperus virginiana) Woodland Alliance (A.1913).

Range: Woodlands in this alliance are currently defined from 1000-3800 feet elevation in the southern and central Blue Ridge and in the upper Piedmont of the United States.

States/Provinces: AL? GA MD NC PA SC? TN VA WV?

TNC Ecoregions: 50:C, 51:C, 52:C, 59:C, 60:P

USFS Ecoregions: 212A:CC, 212B:CC, 221A:CC, 221Bd:CCP, 231Aa:CCC, 231Ae:CCC, 231Ak:CCC, 231Al:CCC, 231Ap:CCC, M221Aa:CCC, M221Ab:CC?, M221B:C?, M221Ca:CC?, M221Cb:CC?, M221Cc:CC?, M221Ce:CCC, M221Da:CCC, M221Db:CCC, M221Dc:CCC, M221Dd:CCC

Federal Lands: NPS (Blue Ridge Parkway, Great Smoky Mountains, Shenandoah); USFS (Cherokee, George Washington, Jefferson, Nantahala, Oconee, Pisgah)

Synonymy: Low Elevation Granitic Dome, Basic Variant, in part (Schafale and Weakley 1990); Piedmont / Mountain Basic Woodland, in part (Fleming et al. 2001); Red-cedar - mixed hardwood rich shale woodland (Fike 1999); Appalachian Shale Barren, Central Appalachian subtype (Smith 1991)

References: Crites and Clebsch 1986, Dellinger 1992, Fike 1999, Fleming 1999, Fleming et al. 2001, Schafale and Weakley 1990, Small 1996, Smith 1991

Authors: A.S. WEAKLEY, MOD. L. SNE, RW, Southeast Identifier: A.604

Concept: This shale barren woodland community occurs on steep slopes of the Central Appalachians. The circumneutral to basic soils are derived from calcareous shales of the Jennings and Hampshire Shale formations on steep, south- or southwest-facing slopes. Soils are thin but generally better developed than other shale barren associations of steeper slopes. The woodland canopy ameliorates to some degree the otherwise xeric conditions imposed by exposure and slope. Canopy closure varies from 20-26% cover over an herbaceous layer that forms 30-90% ground cover. The canopy is codominated by Juniperus virginiana and Fraxinus americana, with other associates including Carya glabra, Quercus prinus, Quercus rubra, and Amelanchier arborea. The herbaceous layer is very diverse. Characteristic species include Carex pensylvanica, Danthonia spicata, 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, Rhus aromatica, and Arenaria serpyllifolia.

Range: This association is restricted to a single subsection of four states in of the Central Appalachians.

States/Provinces: MD:S?, PA:S?, VA:S?,S?,S1, WV?

TNC Ecoregions: 59:C, 60:P

USFS Ecoregions: 221Bd:CCP, M221Aa:CCC, M221B:C?

Synonymy: Eastern Redcedar: 46 (Eyre 1980) B, Red cedar-white ash alkaline shale woodland (CAP pers. comm. 1998)

References: CAP pers. comm. 1998, Eyre 1980, Fike 1999, Fleming et al. 2001

Authors: ECS Confidence: 1 Identifier: CEGL006037

- Maryland Vegetation Classification Subset Report II. Woodland

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