Classification of Vegetation Communities of Maryland: First Iteration

I. FOREST
I.A.8.N.b. Rounded-crowned temperate or subpolar needle-leaved evergreen forest
I.A.8.N.b.13. PINUS STROBUS - TSUGA CANADENSIS FOREST ALLIANCE
Eastern White Pine - Eastern Hemlock Forest Alliance

Concept: Forests codominated by Pinus strobus and Tsuga canadensis occurring from eastern Wisconsin and the upper peninsula of Michigan to eastern Pennsylvania and Maine, south through the Appalachians to northern Georgia and South Carolina. Isolated occurrences could potentially occur in the Cumberland Plateau of Kentucky and Tennessee. Generally, Tsuga canadensis and Pinus strobus are codominant, but other common associates can include Fagus grandifolia, Acer rubrum, Betula lenta, Betula alleghaniensis, Quercus rubra. Picea rubens is often a component in the northeastern part of range, while Liriodendron tulipifera and Betula lenta are the common associates in the southern Appalachians. Typical shrubs/saplings include Acer spicatum, Hamamelis virginiana, and Acer pensylvanicum (in the north), and Ilex opaca, Leucothoe fontanesiana, Rhododendron maximum (in the south). The herbaceous stratum may be sparse and generally depauperate, including Clintonia borealis, Cypripedium acaule, Gaultheria procumbens, Lycopodium spp., Maianthemum canadense, and Trientalis borealis (in the north), and Chimaphila maculata, Mitchella repens, Galax urceolata, Viola blanda, and Polystichum acrostichoides (in the south). Stands of this alliance are found on acidic, nutrient-poor, usually moderately well-drained soils such as sandy loams. Communities of the eastern portion of the range (New England) generally occur on well-drained midslopes, and apparently are not significantly affected by aspect. In the southern Appalachian Mountains and Cumberland Plateau, these forests occur on alluvial terraces and steep, protected gorge slopes. Communities of this alliance are commonly established following disturbance, either natural (fire, windthrow, catastrophic flood events) or anthropogenic (logging). Old-growth examples of the alliance are known, and these forests were likely to have been widespread prior to European settlement. However, without periodic disturbance, communities of this alliance will eventually succeed to other alliances (Barnes 1991).

Comments: Forests within this alliance can have significant numbers of associated trees and can thus be similar to several other alliances, but it is distinguished by occurring in non-wetland situations and having a canopy dominated by the two nominal species, with less than 25% canopy coverage by deciduous trees. Disjunct occurrences of Pinus strobus are also known from Kentucky's Shawnee Hills (Todd County), but these may be better covered in the Pinus strobus Forest Alliance (A.128).

Range: This alliance is found in northern Wisconsin, Michigan, from western Pennsylvania to Maine, including Connecticut, Massachusetts, Maryland (?), New Hampshire, and New York (?), and in Canada in southern Ontario and possibly southern Quebec. It may occur farther south in the Appalachian Mountains to Virginia and West Virginia. This alliance is also found in Georgia, Kentucky, North Carolina, South Carolina, and Tennessee.

States/Provinces: CT GA KY MA MD ME MI NB NC NH NY ON PA QC? RI SC TN VA VT WI WV

TNC Ecoregions: 44:P, 47:C, 48:C, 49:C, 50:C, 51:C, 52:C, 59:C, 60:C, 61:C, 62:C, 63:C, 64:C

USFS Ecoregions: 212Aa:CCC, 212Ab:CCC, 212Ba:CCC, 212Bb:CCC, 212Ca:CCC, 212Cb:CCC, 212Da:CCC, 212Db:CCP, 212Dc:CCC, 212Ea:CCC, 212Eb:CCC, 212Ec:CCP, 212Ed:CCP, 212Ee:CCC, 212Fa:CCP, 212Fb:CCP, 212Fc:CCC, 212Fd:CCP, 212Ga:CCP, 212Gb:CCP, 212Ha:CC?, 212Hb:CC?, 212He:CCP, 212Hh:CCP, 212Hi:CCP, 212Hj:CCC, 212Hk:CC?, 212Hl:CCC, 212Hm:CCP, 212Hn:CCP, 212Ho:CCC, 212Hp:CCP, 212Hq:CCP, 212Hr:CCP, 212Hu:CC?, 212Hv:CCP, 212Hw:CCP, 212Hx:CCP, 212Hy:CCC, 212Ja:CCC, 212Jb:CCP, 212Jc:CCC, 212Je:CCP, 212Jf:CCP, 212Jj:CCC, 212Jl:CCC, 212Jm:CCC, 212Jn:CCP, 212Jo:CCP, 212Js:CCC, 221Aa:CCP, 221Ab:CCP, 221Ac:CCP, 221Ad:CCP, 221Ae:CCC, 221Af:CCC, 221Ag:CCP, 221Ah:CCP, 221Ai:CCC, 221Aj:CCP, 221Ak:CCC, 221Al:CCC, 221Ba:CCP, 221Bb:CCC, 221Bc:CCP, 221Bd:CCC, 221Da:C??, 221Db:C??, 221Ea:CCP, 221Eb:CCP, 221Ec:CCP, 221Fa:CCP, 221Hc:CCC, 221He:CCC, 221Ja:C??, 222Dg:C??, 222Eo:CCC, 222Ia:C??, 222Ib:C??, 222Ic:C??, 222Ie:C??, 222If:C??, 222Ja:C??, 222Ob:CCP, 231Aa:CC?, 231Ae:CC?, 231Ak:CCC, 231Al:CC?, 231Ap:CCP, M212Aa:CCC, M212Ab:CCC, M212Ac:CC?, M212Ad:CCC, M212Ae:CCC, M212Ba:CCP, M212Bb:CCC, M212Bc:CCC, M212Bd:CCC, M212Ca:CCP, M212Cb:CCC, M212Cc:CCC, M212Cd:CCP, M212Da:CCC, M212Db:CCC, M212Dc:CCC, M212Dd:CCC, M212De:CCC, M212Df:CCC, M212Ea:CCC, M212Eb:CCC, M212Fa:CPP, M212Fb:CPP, M221Aa:CCC, M221Ab:CCC, M221Ac:CCC, M221Ba:CCP, M221Bb:CCC, M221Bc:CCP, M221Bd:CCC, M221Be:CCP, M221Bf:CCP, M221Ca:CCP, M221Cb:CCP, M221Cc:CC?, M221Cd:CC?, M221Da:CCC, M221Db:CC?, M221Dc:CCC, M221Dd:CCC

Federal Lands: NPS (Acadia, Great Smoky Mountains); USFS (Chattahoochee, Cherokee, Daniel Boone, George Washington, Jefferson, Nantahala, Pisgah, Sumter)

Synonymy: IA5b. Southern Appalachian Hemlock Cove Forest, in part (Allard 1990); Canada Hemlock Forest, in part (Schafale and Weakley 1990); White Pine - Hemlock: 22, in part (Eyre 1980); Eastern White Pine: 21, in part (Eyre 1980); beech-hemlock association (Morey 1936); Pinus - Tsuga (Morey 1936); hemlock - white pine group (Brown et al. 1982b); hemlock - beech forest type (Gordon 1937b); white pine region, in part (Bromley 1935); Northern Hardwoods - Hemlock - White Pine Forest (Swain and Kearsley 2001); Spruce - Fir - Northern Hardwoods Forest (Swain and Kearsley 2001)

References: Allard 1990, Barnes 1991, Bromley 1935, Brown et al. 1982b, DeYoung 1979, Eyre 1980, Faber-Langendoen et al. 1996, Gordon 1937b, Hinkle 1978, Morey 1936, Patterson 1994, Rawinski et al. 1996, Schafale and Weakley 1990, Seischab 1990, Swain and Kearsley 2001, Thomas 1966, Thomas 1989, Tobe et al. 1992

Authors: M.P. SCHAFALE/A.S. WEAKLE, RW, East Identifier: A.127

Concept: This dry-mesic white pine - hemlock forest of the Central Appalachian Mountains and High Allegheny Plateau occurs on well-drained, nutrient-poor acidic soils. The vegetation is a closed-canopy conifer forest dominated by Pinus strobus and/or Tsuga canadensis. Canopy associates include Fagus grandifolia, Acer rubrum, Betula lenta, Betula alleghaniensis, Quercus rubra, and Liriodendron tulipifera. The sparse shrub layer contains Acer spicatum, Hamamelis virginiana, Acer pensylvanicum, and Viburnum acerifolium. Rhododendron maximum also occurs in this association in northern Pennsylvania. The sparse herb layer includes Cypripedium acaule, Gaultheria procumbens, Lycopodium spp., Maianthemum canadense, Trientalis borealis, Mitchella repens, Medeola virginiana, and Polystichum acrostichoides.

Comments: The compositional and environmental factors that differentiate these community types need further scrutiny. Additional inventory and data collection is needed for further evaluation of this vegetation type's distribution and characterization.

Range: The range of this community type includes the northern Blue Ridge, Ridge and Valley province, and Appalachian Mountains in Virginia, West Virginia, and Maryland. In Virginia, the type has been documented primarily from the northern Blue Ridge but is probably scattered throughout the state's mountain region north of the New River. One outlier apparently belonging to this association has been documented in the western Piedmont.

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

TNC Ecoregions: 52:C, 59:C

USFS Ecoregions: 212F:CC, 212G:CC, 221F:CC, 231Ak:CCC, M221Aa:CCC, M221Ab:CCC, M221Ac:CCC, M221Bb:CCC, M221Bd:CCC, M221Be:CCP, M221Bf:CCP, M221C:CC, M221Da:CCC

Federal Lands: USFS (George Washington, Jefferson)

Synonymy: Tsuga canadensis - Pinus strobus - Fagus grandifolia / Polystichum acrostichoides Forest (Fleming and Coulling 2001), Northern conifer forest (Smith 1983) B. in part, Hemlock - beech consociation (Lutz 1930), Tsuga canadensis / Ilex verticillata / Osmunda regalis Association (Rawinski et al. 1996), White Pine - Hemlock: 22 (Eyre 1980) B. in part

References: Eyre 1980, Fike 1999, Fleming and Coulling 2001, Fleming et al. 2001, Lutz 1930, Rawinski et al. 1996, Smith 1983

Authors: G. Fleming and P. Coulling, ECS Confidence: 3 Identifier: CEGL006019

- Maryland Vegetation Classification Subset Report I.A. Evergreen forest

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