Classification of Vegetation Communities of Maryland: First Iteration
A Subset of the International Classification of Ecological
Concept: This alliance contains woodland communities in which Quercus muehlenbergii is a characteristic, and sometimes dominant, tree. Communities of this alliance are usually restricted to shallow soils derived from calcareous bedrock on gently rolling terrain or on slopes. The moisture regime of these communities is generally dry to well-drained. The canopy is often sparse, with widely spaced trees, although the physiognomy is variable. These woodlands often occur in association with 'glade' vegetation. Associated canopy species include Quercus alba, Celtis tenuifolia, Cercis canadensis, Cornus florida, Carya ovata, Carya carolinae-septentrionalis, Fraxinus americana, Fraxinus quadrangulata, Ostrya virginiana, and Juniperus virginiana var. virginiana. In addition, Quercus austrina may be present within its range. Shrubs are sparse in some examples, the understory characterized by light-demanding herbs such as Bouteloua curtipendula, Asclepias verticillata, Schizachyrium scoparium, Helianthus divaricatus, Sorghastrum nutans, Eryngium yuccifolium, Carex meadii, Anemone cylindrica, Desmodium spp., and Andropogon gerardii. Some more shrubby Alabama dolomite examples may contain Sideroxylon lycioides, Acer leucoderme, Cercis canadensis var. canadensis, Cornus florida, Hypericum frondosum, and Croton alabamensis var. alabamensis. Kentucky, Tennessee, and Arkansas examples contain Cercis canadensis as an associate in the subcanopy. In addition, Kentucky (and Tennessee) examples would probably have Acer saccharum, Quercus stellata, and Juniperus virginiana var. virginiana on shallow, dry, calcareous soils. There are several other associations in the Northeast and Midwest. Primarily on limestone in the Ozarks and the sedimentary rock provinces of the Appalachians.
Comments: Related vegetation of the Interior Low Plateau (Ecoregion 44) is probably placed either in the I.B.2.N.a Quercus muehlenbergii - (Acer saccharum) Forest Alliance (A.1912), e.g., Quercus muehlenbergii - Quercus (falcata, shumardii, stellata) / Cercis canadensis / Viburnum rufidulum Forest (CEGL007699), or the II.B.2.N.a Fraxinus quadrangulata - (Juniperus virginiana) Woodland Alliance (A.1913). Kentucky, Tennessee, and Ecoregion 44 were removed from distribution of this alliance (99-12-22 MP). Related vegetation (without Quercus macrocarpa) on the Knobstone escarpment (Knobs region) within the Daniel Boone National Forest would probably be accommodated under Quercus muehlenbergii - Quercus (falcata, shumardii, stellata) / Cercis canadensis / Viburnum rufidulum Forest (CEGL007699) in I.B.2.N.a; the same is probably true of vegetation reported by Julian Campbell (pers. comm.), with Quercus stellata in the inner Bluegrass 'Palisades' region of Kentucky.
Range: This alliance is found in Iowa, Illinois, Kansas, Missouri, Wisconsin, Alabama, Arkansas, Maryland, Texas, Pennsylvania, Virginia, and West Virginia, and possibly in Michigan (?), and Louisiana (?). It is not thought to occur in Oklahoma (B. Hoagland pers. comm.), nor in Georgia (J. Ambrose pers. comm.).
States/Provinces: AL AR IA IL? KS LA? MD MI MO OH? OK? ON PA TN TX? VA VT WI WV
TNC Ecoregions: 36:C, 37:C, 38:C, 39:?, 40:C, 43:?, 46:C, 48:C, 49:C, 50:C, 59:C
USFS Ecoregions: 212Ea:CCC, 221D:C?, 221Ec:CC?, 221Ha:CCP, 221Hc:CCP, 221Hd:CCP, 221He:CCP, 221Ja:CCP, 221Jb:CCP, 221Jc:CCP, 222Ab:CCC, 222Ac:CCC, 222Af:CCP, 222Ag:CCC, 222Ah:CCP, 222Ak:CC?, 222Am:CC?, 222An:CCC, 222Ao:CCC, 222De:CCP, 222Dg:CCC, 222Ea:CC?, 222Eb:CC?, 222Ec:CCP, 222Ed:CCP, 222Eg:CCP, 222Eh:CC?, 222Fa:CC?, 222Fb:CCP, 222I:CC, 222Lc:CCC, 231Cc:C??, 231Cd:C??, 231Cf:C??, 231Cg:C??, 231Da:CC?, 231Dc:CCC, 231De:CC?, 231Eb:CCC, 231Ga:CP?, 231Gb:CP?, 231Gc:CP?, 232Br:CCC, 251Cq:CCC, 251Ea:CCC, M212A:CC, M221Aa:CCC, M221Ab:CCC, M221Ac:CCC, M221Be:CCC, M222Aa:CCC, M222Ab:CCP
Federal Lands: COE (Lake Millwood); NPS (Buffalo); USFS (George Washington, Jefferson, Mark Twain, Ozark)
Synonymy: Red-cedar - redbud shrubland (Fike 1999); Northern Appalachian Calcareous Rocky Summit (Smith 1991)
References: Ambrose pers. comm., Bartgis 1993, Faber-Langendoen et al. 1996, Fike 1999, Hoagland pers. comm., Smith 1991
Authors: D.J. ALLARD, MP, Midwest Identifier: A.621
QUERCUS MUEHLENBERGII - CERCIS CANADENSIS / PACKERA OBOVATA -
LITHOSPERMUM CANESCENS WOODLAND
Concept: This open calcareous glade occurs in the Central Appalachians in the Ridge and Valley of northeastern West Virginia, western Virginia, and in central southeastern Pennsylvania. The vegetation occurs on moderate slopes at elevations ranging from 1300-2400 feet. Slopes are typically south- or southwest-facing and about 20-30 degrees but may be much steeper. Soils are shallow, dry, stony, calcareous loams derived from limestone or dolomite bedrock. Trees are generally widely spaced and relatively short (3-10 m). Quercus muehlenbergii is the dominant tree, with associates including Cercis canadensis, Juniperus virginiana, Celtis tenuifolia, Fraxinus americana, and Ostrya virginiana usually present. Shrubs are often of sparse cover but may include Rhus aromatica and Rosa sp. (= Rosa tenuifolia?). Cornus florida may be a common woody associate in West Virginia and Pennsylvania. The herbaceous layer is patchy but may be quite diverse. Graminoids include Bouteloua curtipendula, Carex eburnea, Elymus hystrix (= Hystrix patula), Carex pensylvanica, Poa compressa, Danthonia spicata. Associated forbs include Anemone virginiana, Symphyotrichum undulatum (= Aster undulatus), Symphyotrichum oblongifolium (= Aster oblongifolius), Asclepias verticillata, Houstonia longifolia, Penstemon hirsutus, Viola spp., Antennaria plantaginifolia, Phlox subulata, Lithospermum canescens, Cynoglossum officinale, Allium cernuum, Solidago ulmifolia, Solidago arguta var. harrisii (= Solidago harrisii), Packera obovata (= Senecio obovatus), Blephilia ciliata, Galium pilosum, Arabis lyrata, Heuchera americana, Draba ramosissima, Pycnanthemum incanum, Aquilegia canadensis, Helianthus divaricatus, Scutellaria ovata, Silene caroliniana ssp. pensylvanica (= Silene pensylvanica), Sisyrinchium mucronatum, Minuartia michauxii (= Arenaria stricta), Euphorbia corollata, Paronychia montana, and Paronychia virginica.
Comments: Field survey of this vegetation and its cliff habitats can be a dangerous undertaking and many stands have not been thoroughly explored or plot-sampled. Most Virginia occurrences are small (0.1-1.0 ha ) but some exceed 4.0 ha (10 acres) on the more massive cliffs. This community type is distinct from prairie-like calcareous "barrens" occurring on steep hillslopes and dominated by warm-season perennial grasses (e.g., Schizachyrium scoparium, Andropogon gerardii, Bouteloua curtipendula, Sorghastrum nutans) with scattered woody scrub. These barrens are represented in western Virginia by two community types, neither of which is known to occur in the George Washington and Jefferson national forests.
At present, this type is a broadly defined unit that encompasses a variety of rocky calcareous habitats. Virginia stands of this vegetation have a strong restriction to cliffs and rocky escarpments, as well as a composition that differs somewhat from stands in other portions of the range. These differences are reflected in the State Name, which is more useful for field identification and descriptive purposes in Virginia. However, there is some compositional and environmental heterogeneity among the plot samples supporting our interpretation of this vegetation, with six plots representing strict cliff/outcrop vegetation on limestone and three plots representing clifftop habitats on dolomite. The latter subgroup has habitats with considerable areas of exposed mineral soil and has much higher mean species richness (n = 83 taxa per 400 m2 vs. 37 taxa per 100 m2). Additional data collection and analysis over the full geographic range and in Virginia is clearly warranted and will likely result in splitting of this type.
A Juniperus virginiana - Quercus muehlenbergii / Carex eburnea Woodland community identified by Fleming (1999) appears to be a segregate associated with xeric cliffs.
Range: This community is found in the ridge and valley region of northeastern West Virginia, western Virginia, and calcareous areas in central and southeastern Pennsylvania. Its range in West Virginia is limited.
States/Provinces: MD:S?, OH?, PA:S?,S?, VA:S?, WV:S?
TNC Ecoregions: 49:C, 50:P, 59:C
USFS Ecoregions: 212Ea:CCC, 221D:C?, 221Ec:CC?, M212A:CC, M221Aa:CCC, M221Ab:CCP, M221Ac:CCC, M221Be:CCC
Federal Lands: USFS (George Washington, Jefferson)
Synonymy: Juniperus virginiana var. virginiana - Quercus muehlenbergii / Carex eburnea Woodland (4.2) (Fleming 1999), Juniperus virginiana - Quercus muehlenbergii / Carex eburnea - Pellaea atropurpurea Woodland (Fleming and Coulling 2001), Chinquapin oak-redbud calcareous woodland (northern type?) (CAP pers. comm. 1998), Glade Woodland (Bartgis 1993)
References: Bartgis 1993, CAP pers. comm. 1998, Fike 1999, Fleming 1999, Fleming and Coulling 2001, Fleming et al. 2001, Grossman et al. 1994, Sneddon and Menard 2002
Authors: G. Fleming and P. Coulling, ECS Confidence: 2 Identifier: CEGL006231
- Maryland Vegetation Classification Subset Report II. Woodland
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