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CEGL006003 Fraxinus nigra - Abies balsamea / Rhamnus alnifolia Swamp Forest

Type Concept Sentence: No Data Available

Common (Translated Scientific) Name: Black Ash - Balsam Fir / Alderleaf Buckthorn Swamp Forest

Colloquial Name: Central Appalachian Circumneutral Seepage Swamp Forest

Hierarchy Level:  Association

Type Concept: This community is a lush, circumneutral, seepage-fed, mixed woodland or forested swamp of the Allegheny Mountains region of West Virginia. It is a late-successional, small-patch community limited to frost-pocket wetlands on the Mississippian Greenbrier limestone, at elevations between 960 and 1000 m. The community occurs on temporarily to semipermanently flooded, flat headwater basins and backswamps along small streams. Microtopography is characterized by irregular hummocks formed over buttressed tree roots, tip-up mounds, nurse logs, and decaying wood. Soils are poorly drained muck or organic-rich silt loam over mottled or gleyed silty clay. This rich swamp provides habitat for a number of rare shade-tolerant calciphile wetland species. The canopy is open to closed and dominated by stunted, inundation-stressed Abies balsamea, Fraxinus nigra, and Tsuga canadensis. The subcanopy is dominated by Abies balsamea with varying amounts of Betula alleghaniensis var. alleghaniensis, Tsuga canadensis, Picea rubens, and Fraxinus nigra. The tall-shrub layer is dominated by Alnus incana ssp. rugosa with locally abundant Ilex verticillata and sometimes vigorous Picea rubens regeneration in this stratum. The short-shrub layer is dominated by Rhamnus alnifolia or rarely by Cornus amomum. The herbaceous ground layer is extensive and diverse, typically including over 50 species. The most abundant species are Carex bromoides ssp. bromoides and Glyceria striata. Other common species include Arisaema triphyllum, Caltha palustris var. palustris, Carex gynandra, Dryopteris cristata, Impatiens capensis, Juncus effusus, Lycopus uniflorus, Maianthemum canadense, Osmunda cinnamomea var. cinnamomea, Packera aurea, Polygonum sagittatum, Rubus hispidus, and Solidago rugosa. Poa alsodes is locally abundant. Dominant bryophytes are Sphagnum spp., Hypnum imponens, Thuidium delicatulum, and Bazzania trilobata. The community has a large number of diagnostic species, including Carex bromoides ssp. bromoides, Carex crinita, Clematis virginiana, Cornus amomum, Dryopteris cristata, Epilobium coloratum, Euphorbia purpurea, Fraxinus nigra, Galium asprellum, Geum rivale, Milium effusum var. cisatlanticum, Oxypolis rigidior, Polemonium vanbruntiae, Rhamnus alnifolia, and Smilax tamnoides. Mean species richness of all vascular plants and any nonvascular plants with cover >1% is 70 taxa per 400 m2.

Diagnostic Characteristics: No Data Available

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: Eleven plots were used in modifying the classification of this type as part of a 2004-2006 study of high-elevation wetlands in West Virginia''s Allegheny Mountains region (Byers et al. 2007). The type clusters and ordinates well and has been sampled throughout its small range. It has a large number of indicator species. Seven of the plots were sampled by Ceperley (2002) and used in the initial development of the type. Only two occurrences have been documented, both in Tucker County, West Virginia. It is worth noting that the logged and grazed habitat at Blister Swamp in Pocahontas County, WV, is in a similar geologic and climatic setting and currently has many of the same herbaceous and understory plants as this community. It may eventually develop into this community type within the 40-acre cattle exclosure constructed in 1999, where the dominant physiognomy is currently open wetlands and shrub swamps. A probable occurrence on the unglaciated High Allegheny Plateau, in northeastern McKean County, Pennsylvania (G. Podniesinski pers. comm.), shares many of the same diagnostic species.

Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: No Data Available

Floristics: The community is a lush circumneutral evergreen/deciduous woodland or forested swamp with graminoids dominant in the understory. This rich swamp provides rare habitat for shade-tolerant calciphile wetland species. The canopy is open to closed and dominated by stunted, inundation-stressed Abies balsamea, Fraxinus nigra, and Tsuga canadensis. The canopy rarely exceeds 20 m in height and is generally less than 15 m in height, with 20-60% cover. Other tree species occurring in the canopy include Acer rubrum, Picea rubens, and Betula alleghaniensis var. alleghaniensis. The subcanopy ranges from 5-30% cover and is dominated by Abies balsamea with varying amounts of Betula alleghaniensis var. alleghaniensis, Tsuga canadensis, Picea rubens, and Fraxinus nigra. Acer rubrum, Amelanchier spp., Crataegus spp., and Sorbus americana may be present with very low cover in the subcanopy. The tall-shrub layer ranges from 10-100% cover and is dominated by Alnus incana ssp. rugosa (= Alnus rugosa) with locally abundant Ilex verticillata and sometimes vigorous Picea rubens regeneration in this stratum. Rhododendron maximum may be present with low cover. The short-shrub layer covers 5-30% and is dominated by Rhamnus alnifolia or rarely by Cornus amomum. The herbaceous ground layer is extensive and diverse, ranging from 50-100% cover and typically including over 50 species. The most abundant species are Carex bromoides ssp. bromoides and Glyceria striata. Other common species include Arisaema triphyllum, Caltha palustris var. palustris, Carex gynandra, Dryopteris cristata, Impatiens capensis, Juncus effusus, Lycopus uniflorus, Maianthemum canadense, Osmunda cinnamomea var. cinnamomea, Packera aurea, Polygonum sagittatum, Rubus hispidus, and Solidago rugosa. Poa alsodes is locally abundant. Nonvascular plants have 3-50% cover in this community. Dominant bryophytes are Sphagnum spp., Hypnum imponens, Thuidium delicatulum, and Bazzania trilobata, with 12 other bryophyte species occasionally noted. The community is characterized by a large number of indicator species within the forest/woodland physiognomy for high-elevation wetlands of the Allegheny Mountains region. They include Carex bromoides ssp. bromoides, Carex crinita, Clematis virginiana, Cornus amomum, Dryopteris cristata, Epilobium coloratum, Euphorbia purpurea, Fraxinus nigra, Galium asprellum, Geum rivale, Milium effusum var. cisatlanticum, Onoclea sensibilis, Oxypolis rigidior, Polemonium vanbruntiae, Polygonum sagittatum, Rhamnus alnifolia, Smilax tamnoides, and Viola cucullata. A few globally rare species such as Euphorbia purpurea and Polemonium vanbruntiae are associated with this community. Mean species richness of all vascular plants and any nonvascular plants with cover >1% is 70 taxa per 400 m2 (Ceperley 2002, Byers et al. 2007).

Dynamics:  This is a late-successional, small-patch woodland/forest swamp community. It is fed by circumneutral seepage from the Greenbrier limestone. Nutrient cycling occurs from the decay of fallen trees, broad-leaved deciduous litter, and lush herbaceous vegetation.
Environmental Description:  This community occurs on temporarily to semipermanently flooded, flat headwater basins and backswamps along small streams on the Mississippian Greenbrier limestone in Canaan Valley, in the Allegheny Mountains region of West Virginia, at elevations of 962-989 m above sea level. Microtopography is characterized by irregular mossy hummocks formed over tip-up mounds, nurse logs, decaying wood, and live tree roots. Historic logging and fires around the year 1900 damaged this community. Its wetland setting and stunted (no commercial value) trees offered some protection, and it has recovered well. The rich substrate required by this swamp type has also attracted significant agricultural (grazing and hayfields) pressure in the past. Most stands are adjacent to mowed meadows on at least one side, although cattle grazing pressure has now been removed. Typically, adjacent natural communities include alluvial shrub swamp and upland forest. Current fluctuations in hydrologic regime occur as a result of beaver activity, but do not appear to immediately threaten this community. Excessive deer browse appears to have significant negative impact on regeneration of canopy species and on some rare herbaceous species, e.g., Polemonium vanbruntiae. Most Abies balsamea show damage from Adelges piceae (balsam woolly adelgid), including bark infestation and gout damage. Combined with excessive deer herbivory, the adelgid damage may be severe enough to eliminate Abies balsamea and change the dominant species composition of this community in the future. Minor invasion of exotic plants, particularly Iris pseudacorus and Rosa multiflora, has occurred in a few stands and should be monitored carefully. Soils are poorly drained muck or organic-rich silt loam over mottled or gleyed silty clay, with stoniness <0.1%. Hydric soil indicators include hydrogen sulphide, depleted matrix, redox depressions, and thick dark surface 2/1. Soil chemistry is characterized by high organic matter, Al, Ca, Fe, K, Mg, N, Na, Zn, and total exchange capacity; moderate Cu, P; and low B, H, Mn (n=12). Soil pH averages 5.3 (n=12). Pore water is high in pH (6.4, n=2) and electrical conductivity (322, n=2). The unvegetated surface is variable, with litter and bare ground dominant. Standing water averages 2% and downed wood averages 3% (Ceperley 2002, Byers et al. 2007).
Geographic Range: The known distribution of this community is restricted to frost-pocket, high-elevation wetlands on the Mississippian Greenbrier limestone in Canaan Valley, in the Allegheny Mountains region of West Virginia, at elevations between 960-1000 m above sea level. This type may have historically occurred at a second site with similar geologic and climatic conditions at Blister Swamp in Pocahontas County, WV. A probable occurrence on the unglaciated High Allegheny Plateau, in northeastern McKean County, Pennsylvania (G. Podniesinski pers. comm.), shares many of the same diagnostic species.

Nations: US

States/Provinces:  PA?, WV


Confidence Level: High

Confidence Level Comments: No Data Available
Grank: G1

Greasons: No Data Available
Type Name Database Code Classification Code
Class 1 Forest & Woodland Class C01 1
Subclass 1.B Temperate & Boreal Forest & Woodland Subclass S15 1.B
Formation 1.B.3 Temperate Flooded & Swamp Forest Formation F026 1.B.3
Division 1.B.3.Na Eastern North American-Great Plains Flooded & Swamp Forest Division D011 1.B.3.Na
Macrogroup 1.B.3.Na.2 Pin Oak - Green Ash - Blackgum Swamp Forest Macrogroup M503 1.B.3.Na.2
Group 1.B.3.Na.2.h <i>Quercus bicolor - Fagus grandifolia - Acer rubrum</i> Swamp Forest Group G918 1.B.3.Na.2.h
Alliance A4461 <i>Acer rubrum - Fraxinus pennsylvanica</i> Northeast Alkaline Swamp Forest Alliance A4461 1.B.3.Na.2.h
Association CEGL006003 Black Ash - Balsam Fir / Alderleaf Buckthorn Swamp Forest CEGL006003 1.B.3.Na.2.h
Concept Lineage: No Data Available

Predecessors: No Data Available

Obsolete Names: No Data Available

Obsolete Parents: No Data Available
Synonomy: = Abies balsamea - Fraxinus nigra - Tsuga canadensis / Rhamnus alnifolia seepage wetland (Ceperley 2002)
= Fraxinus nigra - Abies balsamea / Alnus incana ssp. rugosa / Rhamnus alnifolia / Carex bromoides ssp. bromoides Rich Swamp (Byers et al. 2007)
= Fraxinus nigra - Abies balsamea / Rhamnus alnifolia woodland (TNC 1994)
= Picea rubens - Tsuga canadensis - Abies balsamea - Acer rubrum - Betula alleghaniensis (Fraxinus nigra) swamp forest (Fortney 1975)
Concept Author(s): Eastern Ecology Group

Author of Description: E.A. Byers

Acknowledgements: No Data Available

Version Date: 05-07-07
  • Byers, E. A., J. P. Vanderhorst, and B. P. Streets. 2007. Classification and conservation assessment of high elevation wetland communities in the Allegheny Mountains of West Virginia. West Virginia Natural Heritage Program, West Virginia Division of Natural Resources, Elkins.
  • Ceperley, L. 2002. Classification of West Virginia and Virginia Abies balsemea communities affected by balsam woolly adelgid (Adelges piceae) infestation. M.S. thesis, Department of Environmental Studies, Antioch New England Graduate School, Antioch University, Keene, NH. 97 pp.
  • Eastern Ecology Working Group of NatureServe. No date. International Ecological Classification Standard: International Vegetation Classification. Terrestrial Vegetation. NatureServe, Boston, MA.
  • Fortney, R. H. 1975. The vegetation of Canaan Valley, West Virginia: A taxonomic and ecological study. Ph.D. dissertation, University of West Virginia, Morgantown.
  • Fortney, R. H. 1997. A chronology of post logging plant succession in Canaan Valley through the development of a series of vegetation maps from 1945 to present. Unpublished report to the U.S. Environmental Protection Agency. Contract No. X-993402-01.
  • Fortney, R. H., S. L. Stephenson, and J. S. Rentch. 2005. Rare plant communities of Canaan Valley, West Virginia, USA. Unpublished manuscript.
  • Rentch, J. S., R. H. Fortney, J. T. Anderson, and W. N. Grafton. 2002. Plant communities of Abe''s Run Wetland, Canaan Valley State Park. Unpublished report.
  • Stephenson, S. L., and H. S. Adams. 1986. An ecological study of balsam fir communities in West Virginia. Bulletin of the Torrey Botanical Club 113:372-381.
  • TNC [The Nature Conservancy]. 1994. Rare plant communities of the conterminous United States: An initial survey. Arlington, VA. 620 pp.
  • WVNHP [West Virginia Natural Heritage Program]. No date. Unpublished data. West Virginia Natural Heritage Program, Elkins.