Print Report

CEGL006923 Tsuga canadensis - Quercus montana - Betula lenta Forest

Type Concept Sentence: No Data Available


Common (Translated Scientific) Name: Eastern Hemlock - Chestnut Oak - Sweet Birch Forest

Colloquial Name: Central Appalachian Hemlock - Chestnut Oak Forest

Hierarchy Level:  Association

Type Concept: This association is a hemlock - chestnut oak forest which often occurs on steep northeastern to northwestern exposures. It ranges from the New Jersey Highlands south to the Blue Ridge, Ridge and Valley, Allegheny Mountains, Western Allegheny Plateau, and Piedmont provinces of Maryland and West Virginia. Stands occur at elevations from 150 m to about 920 m (500-3010 feet) on moderately to very steep, sheltered slopes. Northerly aspects and middle slope positions prevail among documented examples. Some sites are "boulderfields" with up to 60% cover by large rocks. Geologic substrate is variable. Soils are usually very stony to extremely stony sandy loams, consistently oligotrophic, with very low pH and base status. Stands of this association are typically floristically depauperate and generally dominated by variable combinations of Quercus montana and Tsuga canadensis. Betula lenta and, less commonly, Quercus velutina, Quercus coccinea, and Quercus rubra are major overstory associates, each attaining codominance in a subset of stands. Quercus alba, Acer rubrum, Liriodendron tulipifera, Pinus strobus, Sassafras albidum, and Fagus grandifolia are minor overstory associates. Small trees and shrubs can be absent or sparse due to dense shading by hemlock, with Hamamelis virginiana most consistently providing moderate cover. Less frequently, Kalmia latifolia, Rhododendron maximum, and Viburnum acerifolium are shrub components. At some New Jersey sites, a single dense stratum or multiple open strata of ericaceous species can develop, including Rhododendron maximum, Kalmia latifolia, Gaylussacia baccata, and Vaccinium pallidum. The herb layer of this community is typically very sparse or absent; typical scattered species include Maianthemum canadense, Dennstaedtia punctilobula, Chimaphila maculata, Deschampsia flexuosa, Carex swanii, and Aralia nudicaulis.

Diagnostic Characteristics: No Data Available

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: Because of devastation by hemlock woolly adelgid, understory hemlock is often all that''s left in this community in Virginia. The original description was based on A. Windisch''s (1993) Picatinny Arsenal Hemlock-Mixed Oak-(Heath) Cool Sub-Mesic forest description (TcQf). An expanded circumscription is based on analysis of data from 20 Maryland and Virginia plots, data from Delaware Water Gap, and 12 West Virginia plots. Analysis of more than 1300 montane Virginia plots indicated that the two Virginia plots originally assigned to this type in the National Capital Region analysis are cove plots that are better classified as ~Liriodendron tulipifera - Quercus montana - (Tsuga canadensis) / Kalmia latifolia - (Rhododendron catawbiense) Forest (CEGL008512)$$ (Fleming and Patterson 2009b).

In West Virginia, this association was first applied to plots at Bluestone National Scenic River (Vanderhorst et al. 2008), then to additional plots from the Ridge and Valley and Western Allegheny Plateau. It is distinguished from other hemlock-hardwood forests in the state by having Quercus montana codominant in the canopy and its occurrence on dry sites.

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

Physiognomy and Structure: No Data Available

Floristics: This association is a hemlock - mixed oak forest dominated by Tsuga canadensis in association with species of Quercus and other deciduous trees indicative of relatively dry, infertile soils. Stands are typically floristically depauperate and generally dominated by variable combinations of Quercus montana (= Quercus prinus) and Tsuga canadensis. Betula lenta and, less commonly, Quercus velutina, Quercus coccinea, Quercus alba, and Quercus rubra are major overstory associates, each attaining codominance in a subset of stands. Acer rubrum, Liriodendron tulipifera, Pinus strobus, Sassafras albidum, and Fagus grandifolia are very minor overstory associates. Oxydendrum arboreum and Acer saccharum, along with overstory species, may be present in the subcanopy. Small trees and shrubs are often absent or sparse due to dense shading by hemlock, with Hamamelis virginiana most consistently providing moderate cover. Less frequently, Kalmia latifolia, Rhododendron maximum, Vaccinium pallidum, Amelanchier arborea, and Viburnum acerifolium are shrub components. At some New Jersey sites, a single dense stratum or multiple open strata of ericaceous species can develop, including Rhododendron maximum, Kalmia latifolia, Gaylussacia baccata, and Vaccinium pallidum. The herb layer of this community is typically very sparse or absent with scattered individuals of a few species; typical species vary somewhat with geography and include Maianthemum canadense, Dennstaedtia punctilobula, Dioscorea quaternata, Chimaphila maculata, Deschampsia flexuosa, Dryopteris marginalis, Carex swanii, Eurybia divaricata, Goodyera pubescens, Gaultheria procumbens, Mitchella repens, Monotropa hypopitys, Monotropa uniflora, Parthenocissus quinquefolia, and Aralia nudicaulis. In nine West Virginia plots from Bluestone National Scenic River, vascular plant richness ranged from 16 to 43 (mean = 26.5) species per 400-m2 plot.

Dynamics:  Extensive hemlock mortality caused by hemlock woolly adelgid (Adelges tsugae) is changing the composition of many of these forests. Most Maryland stands are now in a degraded condition, and some have suffered virtually complete hemlock mortality. In Bluestone National Scenic River (WV), many hemlocks appear stressed, but large scale mortality was not observed during the 2003-2006 vegetation surveys.

Environmental Description:  Stands occur at elevations from 150 m to about 920 m (500-3010 feet) on moderately to very steep, sheltered slopes. Northern to northwestern aspects and middle slope positions prevail among documented examples. Some sites are "boulderfields" with up to 60% cover by large rocks; some appear above or below cliff bands. Geologic substrate is variable but includes shales and sandstone. Soils are usually very stony to extremely stony sandy loams, consistently oligotrophic, with very low pH and base status. Soils in eight West Virginia plots in the environs of Bluestone National Scenic River are described as dry to somewhat moist, well-drained, stone-free to very stony sandy loam, silt loam, sandy silt loam, and sandy clay loam; they tested extremely to medium acidic (mean pH = 4.4) with relatively high levels of organic matter, estimated N release, S, Al, B, and Fe and relatively low levels of Ca, Cu, K, Mg, Mn, P, and Zn compared to average values in the area.

Geographic Range: This association ranges from the New Jersey Highlands south to the Blue Ridge, Ridge and Valley, Allegheny Mountains, Western Allegheny Plateau, and Piedmont provinces of Pennsylvania and Maryland, and West Virginia.

Nations: US

States/Provinces:  MD, NJ, NY, PA, WV




Confidence Level: Moderate

Confidence Level Comments: No Data Available

Grank: G3

Greasons: No Data Available


Concept Lineage: No Data Available

Predecessors: No Data Available

Obsolete Names: No Data Available

Obsolete Parents: No Data Available

Synonomy: = Tsuga canadensis - Quercus prinus / Vaccinium pallidum / Gaultheria procumbens Forest [Hemlock - Chestnut Oak Forest] (Vanderhorst 2017c)
> Picatinny Arsenal Hemlock-Mixed Oak-(Heath) Cool Sub-Mesic forest description (TcQf) (Windisch 1993)

Concept Author(s): A.G. Windisch (1993)

Author of Description: A. Windisch, S.C. Gawler, G.P. Fleming, J. Vanderhorst

Acknowledgements: No Data Available

Version Date: 12-20-18

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