Invalid Unit Specified
Macrogroup Detail Report: M504
Tsuga canadensis - Fraxinus nigra - Chamaecyparis thyoides Flooded & Swamp Forest Macrogroup

The U.S. National
Vegetation Classification
This swamp forest macrogroup of the northeastern and north-central U.S. and southeastern Canada is characterized by a mixture of deciduous trees (Acer rubrum, Betula alleghaniensis, Fraxinus nigra, Nyssa sylvatica, Ulmus americana) and coniferous trees (Chamaecyparis thyoides, Larix laricina, Picea rubens, Pinus strobus, Thuja occidentalis, Tsuga canadensis) on organic or mineral soils spanning the pH spectrum from acidic to alkaline.
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Translated Name:Eastern Hemlock - Black Ash - Atlantic White-cedar Flooded & Swamp Forest Macrogroup
Colloquial Name:Laurentian-Acadian-North Atlantic Coastal Flooded & Swamp Forest
This swamp forest macrogroup ranges from temperate regions of northwest Ontario east to Atlantic Canada, and from central Minnesota east to northern New England. It includes deciduous and coniferous trees, including Betula alleghaniensis, Fraxinus nigra, Larix laricina, Picea rubens, Pinus strobus, Thuja occidentalis, and Tsuga canadensis to the north, and Chamaecyparis thyoides and Nyssa sylvatica to the south, with Acer rubrum usually present throughout the range and often strongly dominant in more successional stands. Occasionally, colder conditions favor Abies balsamea, Picea glauca, or Picea mariana, mixed with temperate trees, shrubs, and herbs. This macrogroup covers a wide pH range, and includes alkaline to circumneutral swamps and floodplains characterized by Fraxinus nigra, Thuja occidentalis, and Ulmus americana and acidic swamps characterized by Chamaecyparis thyoides, Picea rubens, and/or lacking Thuja occidentalis and Fraxinus nigra. Common shrubs may include Clethra alnifolia, Gaylussacia dumosa, Ilex glabra, Leucothoe racemosa, Rhododendron viscosum in the south; Alnus incana, Nemopanthus mucronatus, Viburnum nudum var. cassinoides in the north, with Ilex verticillata and Vaccinium corymbosum over much of the range. Ferns may be common, including Dryopteris cristata, Osmunda cinnamomea, Onoclea sensibilis, Thelypteris palustris, and others. Sedges and Sphagnum mosses are common. Hummock-and-hollow microtopography is characteristic, and trees are often primarily confined to hummocks, with more hydrophytic herbaceous vegetation in hollows. These swamps form in basin wetlands that remain saturated for all or nearly all of the growing season, and may have standing water seasonally. Some occur on gently sloping seepage lowlands, and even basin settings may have some seepage influence, especially near the periphery.
Saturated forests with prominent canopy trees including Acer rubrum and associates Chamaecyparis thyoides or Pinus rigida occurring on the Atlantic Coastal Plain from Virginia to southern New England, or Acer rubrum, Betula alleghaniensis, Fraxinus nigra, Larix laricina, Picea rubens, Thuja occidentalis, and Tsuga canadensis inland and to the north. The shrub and herbaceous layers have a significant component of hydrophytes (facultative to obligate wetland species). Ferns are prevalent within these swamp forests, including Dryopteris cristata, Osmunda cinnamomea, Onoclea sensibilis, Thelypteris palustris, and others.
Some species, such as Clethra alnifolia, Gaylussacia dumosa, and Ilex glabra, have coastal plain affinities.
Synonomy: >< Atlantic white cedar wetland (Laderman 1989)
< Northern White-Cedar - Hemlock - Red Spruce Conifer Swamp Group (Faber-Langendoen and Menard 2006)
>< Red maple swamp (Golet et al. 1993)
>< Spring swamp (National Wetlands Working Group 1988)

Related Type Name:

Short Citation:
  • Allison and Ehrenfeld 1999
  • Alverson and Waller 1997
  • Anderson and Leopold 2002
  • Augustine and Frelich 1998
  • Balgooyen and Waller 1995
  • Coffman 1978
  • Cohen et al. 2014
  • Faber-Langendoen and Menard 2006
  • Faber-Langendoen et al. 2017a
  • Forrester et al. 2005
  • Frelich and Lorimer 1985
  • Golet et al. 1993
  • Holcombe 1976
  • Kost et al. 2007
  • Kraft et al. 2004
  • Krueger and Peterson 2006
  • Laderman 1989
  • Laidig and Zampanella 1999
  • Long et al. 1998
  • McGee 2001
  • Mladenoff and Stearns 1993
  • National Wetlands Working Group 1988
  • Rooney and Waller 1998
  • Rooney and Waller 2003
  • Rooney et al. 2002
  • Slaughter et al. 2007
  • St. Hilaire and Leopold 1995
  • Tepley et al. 2004
States/Provinces:CT, DE, IL, IN, MA, MD, ME, MI, MN, NB, NH, NJ, NS, NY, OH, ON, PA, QC, RI, VA, VT, WI, WV
Nations:CA, US
Range:This macrogroup ranges from New England west to Minnesota, south along the Appalachian Mountains to Virginia, and east to the Atlantic Coastal Plain.
US Forest Service Ecoregions
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Deciduous, mixed, or coniferous canopy ranging from dense to partially open; shrub layer generally well-developed but can be sparse under dense canopy and where deer browse pressure is high. Hummock-and-hollow microtopography is characteristic, and mosses, especially species of Sphagnum, are common and usually abundant. Hummocks and decaying nurse logs provide critical substrate for plant establishment and growth.
Acer rubrum is a relatively constant species throughout the range of these swamps. At the northern end of the range, canopy trees Betula alleghaniensis, Larix laricina, Picea rubens, Pinus strobus, and Tsuga canadensis are characteristic. Nyssa sylvatica can be more important toward the southern end of the range. Occasionally, colder conditions favor Abies balsamea, Picea glauca, or Picea mariana, mixed with temperate trees, shrubs, and herbs. Typical shrubs include Alnus incana, Carpinus caroliniana, Cornus spp., Ilex verticillata, Lindera benzoin, Nemopanthus mucronatus, Ribes spp., Rubus pubescens, Salix spp., Vaccinium corymbosum, and Viburnum nudum var. cassinoides. On the coastal plain, Picea rubens and Larix laricina are replaced by Chamaecyparis thyoides or Pinus rigida, with typical shrubs including Clethra alnifolia, Gaylussacia dumosa, Ilex glabra, Leucothoe racemosa, and Rhododendron viscosum. Typical herbs across the range of acidic swamps include Carex folliculata, Carex intumescens, Carex scabrata, Carex stricta, Chelone glabra, Dryopteris cristata, Onoclea sensibilis, Osmunda spp., Saxifraga pensylvanica, and Symplocarpus foetidus, among others. Alkaline swamps are limited to the northern portion of the range of this macrogroup and are characterized by Acer rubrum, Fraxinus nigra, Larix laricina, Thuja occidentalis, and Ulmus americana, with shrubs including Rhamnus alnifolia and Cornus sericea in addition to the shrubs of northern acidic swamps. Herbaceous species of alkaline swamps include Caltha palustris, Carex bromoides, Carex leptalea, Geum rivale, Impatiens capensis, and Packera aurea, in addition to many of the acidic swamp species listed above.
From Slaughter et al. (2007): "Hardwood-conifer swamp occurs on a variety of landforms, including poorly-drained outwash channels and outwash plains and depressions on medium- to coarse-textured end moraines, ground moraines, and glacial lakeplains (Kost et al. 2007). The community occupies sites influenced by groundwater seepage, usually where the water table is at or near the soil surface. Hardwood-conifer swamp occurs on gently sloping to flat topography along headwater streams or in association with relatively inactive portions of floodplains of low order streams, where it forms backswamps or occurs in meander scars (Tepley et al. 2004). Shallow kettle depressions and the margins of large forested and non-forested peatlands may also support hardwood-conifer swamp, but the community is absent from areas where significant peat accumulation isolates the rooting zone from contact with mineral-rich groundwater." The type may also occur in floodplains. The substrate is either wet mineral soils or peat, and hummocky topography is present. The groundwater ranges from low to high base status.
Moderate
From Slaughter et al. (2007): "The primary natural processes structuring hardwood-conifer swamp are small-scale windthrow and dynamics of surface water and groundwater. Patchy windthrow is the dominant natural disturbance, creating small-scale canopy gaps (Forrester et al. 2005).

"Seedlings of several characteristic hardwood-conifer swamp canopy species (e.g., yellow birch, white pine, northern white-cedar, and hemlock) preferentially germinate and establish on root hummocks and/or decaying logs versus muck or litter-covered depressions (i.e., hollows) (Holcombe 1976, St. Hilaire and Leopold 1995, Rooney and Waller 1998, Allison and Ehrenfeld 1999, McGee 2001, Rooney et al. 2002). In comparison to hollows, hummocks and decaying logs have high moss cover, high moisture content, coarse substrate texture, and stable hydrology, characteristics which may favor the germination and establishment of small seeds with low nutrient reserves (Coffman 1978, St. Hilaire and Leopold 1995, McGee 2001).

"Groundwater and surface water dynamics also shape hardwood-conifer swamp structure and impact succession. Significant hydrological processes impacting hardwood-conifer swamp include groundwater seepage, water table fluctuation, seasonal inundation, and flooding events. "

Logging, especially of Thuja occidentalis and Chamaecyparis thyoides, has influenced the structure and dominance of this macrogroup. Regeneration of Chamaecyparis thyoides is stimulated by fire.

At the present time, excessive deer herbivory threatens the viability of hardwood-conifer swamp throughout its range. High white-tailed deer (Odocoileus virginianus) density is leading to considerable browse pressure on conifer seedlings and saplings throughout Michigan and the Great Lakes region (Frelich and Lorimer 1985, Mladenoff and Stearns 1993, Alverson and Waller 1997, Long et al. 1998, Rooney and Waller 1998, Rooney et al. 2002, Krueger and Peterson 2006). Deer browse also reduces frequency and cover of understory shrubs and herbs (Balgooyen and Waller 1995, Augustine and Frelich 1998, Rooney and Waller 2003, Kraft et al. 2004). The result of heavy deer browse is significant alteration of community structure consisting of impacts to all vegetative strata.
Authors:
L. Sneddon and C. Lea      Version Date: 05Jun2015


References:
  • Allison, S. K., and J. G. Ehrenfeld. 1999. The influence of microhabitat variations on seedling recruitment of Chamaecyparis thyoides and Acer rubrum. Wetlands 19:383-393.
  • Alverson, W. S., and D. M. Waller. 1997. Deer populations and the widespread failure of hemlock regeneration in northern forests. Pages 280-297 in: W. J. McShea, H. B. Underwood, and J. H. Rappole, editors. The science of overabundance: Deer ecology and population management. Smithsonian Institution Press, Washington, DC. 402 pp.
  • Anderson, K. L., and D. J. Leopold. 2002. The role of canopy gaps in maintaining vascular plant diversity at a forested wetland in New York State. Journal of the Torrey Botanical Society 129:238-250.
  • Augustine, D. J., and L. E. Frelich. 1998. Effects of white-tailed deer on populations of an understory forb in fragmented deciduous forests. Conservation Biology 12(5):995-1004.
  • Balgooyen, C. P., and D. M. Waller. 1995. The use of Clintonia borealis and other indicators to gauge impacts of white-tailed deer on plant communities in northern Wisconsin. USA. Natural Areas Journal 15(4):308-318.
  • Coffman, M. S. 1978. Eastern hemlock germination influenced by light, germination media, and moisture content. Michigan Botanist 17:99-103.
  • Cohen, J. G., M. A. Kost, B. S. Slaughter, and D. A. Albert. 2014. A field guide to the natural communities of Michigan. Michigan State University Press, East Lansing, MI. 362 pp.
  • Faber-Langendoen, D., and S. Menard. 2006. A key to eastern forests of the United States: Macrogroups, groups, and alliances. September 15, 2006. NatureServe, Arlington, VA.
  • Faber-Langendoen, D., J. Drake, S. Gawler, M. Hall, C. Josse, G. Kittel, S. Menard, C. Nordman, M. Pyne, M. Reid, L. Sneddon, K. Schulz, J. Teague, M. Russo, K. Snow, and P. Comer, editors. 2010-2017a. Divisions, Macrogroups and Groups for the Revised U.S. National Vegetation Classification. NatureServe, Arlington, VA. plus appendices. [in preparation]
  • Forrester, J. A., T. E. Yorks, and D. J. Leopold. 2005. Arboreal vegetation, coarse woody debris, and disturbance history of mature and old-growth stands in a coniferous forested wetland. Journal of the Torrey Botanical Society 132:252-261.
  • Frelich, L. E., and C. G. Lorimer. 1985. Current and unpredicted long-term effects of deer browsing in hemlock forests in Michigan, USA. Biological Conservation 34:99-120.
  • Golet, F. C., A. J. K. Calhoun, W. R. DeRagon, D. J. Lowry, and A. J. Gold. 1993. Ecology of red maple swamps in the glaciated Northeast: A community profile. USDI Fish & Wildlife Service, Washington, DC. 151 pp.
  • Holcombe, J. W. 1976. The bryophyte flora of Thuja seedbed logs in a northern white-cedar swamp. Michigan Botanist 15:173-181.
  • Kost, M. A., D. A. Albert, J. G. Cohen, B. S. Slaughter, R. K. Schillo, C. R. Weber, and K. A. Chapman. 2007. Natural communities of Michigan: Classification and description. Report No. 2007-21, Michigan Natural Features Inventory, Lansing. 314 pp. [http://web4.msue.msu.edu/mnfi/reports/2007-21_Natural_Communites_of_Michigan_Classification_and_Description.pdf]
  • Kraft, L. S., T. R. Crow, D. S. Buckley, E. A. Nauertz, and J. C. Zasada. 2004. Effects of harvesting and deer browsing on attributes of understory plants in northern hardwood forests, Upper Michigan, USA. Forest Ecology and Management 199:219-230.
  • Krueger, L. M., and C. J. Peterson. 2006. Effects of white-tailed deer on Tsuga canadensis regeneration: Evidence of microsites as refugia from browsing. American Midland Naturalist 156:353-362.
  • Laderman, A. D. 1989. The ecology of the Atlantic white cedar wetlands: A community profile. USDI Fish and Wildlife Service. Biological Report 85(7.21). 114 pp.
  • Laidig, K. L., and R. A. Zampanella. 1999. Community attributes of Atlantic white cedar (Chamaecyparis thyoides) swamps in disturbed and undisturbed Pinelands watersheds. Wetlands 19:35-49.
  • Long, R. A., A. F. O’Connell, Jr., and D. J. Harrison. 1998. Mortality and survival of white-tailed deer Odocoileus virginianus fawns on a north Atlantic coastal island. Wildlife Biology 4:237-247.
  • McGee, G. G. 2001. Stand-level effects on the role of decaying logs as vascular plant habitat in Adirondack northern hardwood forests. Journal of the Torrey Botanical Society 128:370-380.
  • Mladenoff, D. J., and F. Stearns. 1993. Eastern hemlock regeneration and deer browsing in the northern Great Lakes region: A re-examination and model simulation. Conservation Biology 7:889-900.
  • National Wetlands Working Group. 1988. Wetlands of Canada. Ecological Land Classification Series, No. 24. Sustainable Development Branch, Environment Canada, Ottawa, Ontario, and Polyscience Publications Inc., Montreal, Quebec. 452 pp.
  • Rooney, T. P., and D. M. Waller. 1998. Local and regional variation in hemlock seedling establishment in forests of the upper Great Lakes region, USA. Forest Ecology and Management 111:211-224.
  • Rooney, T. P., and D. M. Waller. 2003. Direct and indirect effects of white-tailed deer in forest ecosystems. Forest Ecology and Management 181:165-176.
  • Rooney, T. P., S. L. Solheim, and D. M. Waller. 2002. Factors affecting the regeneration of northern white cedar in lowland forests of the Upper Great Lakes region, USA. Forest Ecology and Management 163:119-130.
  • Slaughter, B. S., J. G. Cohen, and M. A. Kost. 2007. Natural community abstract for hardwood-conifer swamp. Michigan Natural Features Inventory, Lansing. 20 pp.
  • St. Hilaire, L. R., and D. J. Leopold. 1995. Conifer seedling distribution in relation to microsite conditions in a central New York forested minerotrophic peatland. Canadian Journal of Forest Research 25:261-269.
  • Tepley, A. J., J. G. Cohen, and L. Huberty. 2004. Natural community abstract for southern floodplain forest. Michigan Natural Features Inventory, Lansing, MI. 14 pp.


USNVC Credits: Detailed Description of the National Vegetation Classification Types

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To cite a description:
Author(s). publicationYear. Description Title [last revised revisionDate]. United States National Vegetation Classification. Federal Geographic Data Committee, Washington, D.C.

About spatial standards:
The United States Federal Geographic Data Committee (hereafter called the FGDC) is tasked to develop geospatial data standards that will enable sharing of spatial data among producers and users and support the growing National Spatial Data Infrastructure (NSDI), acting under the Office of Management Budget (OMB) Circular A-16 (OMB 1990, 2000) and Executive Order #12906 (Clinton 1994) as amended by Executive Order #13286 (Bush 2003). FGDC subcommittees and working groups, in consultation and cooperation with state, local, tribal, private, academic, and international communities, develop standards for the content, quality, and transferability of geospatial data. FGDC standards are developed through a structured process, integrated with one another to the extent possible, supportable by the current vendor community (but are independent of specific technologies), and publicly available.

About this document
This document contains type descriptions at the Macrogroup level of the U.S. National Vegetation Classification. These descriptions were primarily written by NatureServe ecologists in collaboration with Federal Geographic Data Committee Vegetation Subcommittee and a wide variety of state, federal and private partners as a part of the implementation of the National Vegetation Classification. Formation descriptions were written by the Hierarchy Revisions Working Group. The descriptions are based on consultation with natural resource professionals, published literature, and other vegetation classification systems. The Ecological Society of America's Panel on Vegetation Classification is responsible for managing the review and formal adoption of these types into the National Vegetation Classification. Partners involved in the implementation of the USNVC include:

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  • Department of Commerce (DOC)
  • Department of Defense (DOD)
  • Department of the Interior (USDI)
  • Forest Service (FS) - Chair
  • National Agriculture Statistical Service (NASS)
  • Natural Resources Conservation Service (NRCS)
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Non U.S. Government
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Disclaimer:
Given the dynamic nature of the standard, it is possible a type description is incomplete or in revision at the time of download; therefore, users of the data should track the date of access and read the revisions section of the USNVC.org website to understand the current status of the classification. While USNVC data have undergone substantial review prior to posting, it is possible that some errors or inaccuracies have remained undetected.

For information on the process used to develop these descriptions see:

Faber-Langendoen, D., T. Keeler-Wolf, D. Meidinger, D. Tart, B. Hoagland, C. Josse, G. Navarro, S. Ponomarenko, J.-P. Saucier, A. Weakley, P. Comer. 2014. EcoVeg: A new approach to vegetation description and classification. Ecological Monographs 84:533-561 (erratum 85:473).

Franklin, S., D. Faber-Langendoen, M. Jennings, T. Keeler-Wolf, O. Loucks, A. McKerrow, R.K. Peet, and D. Roberts. 2012. Building the United States National Vegetation Classification. Annali di Botanica 2: 1-9.

Jennings, M. D., D. Faber-Langendoen, O. L. Louckes, R. K. Peet, and D. Roberts. 2009. Standards for associations and alliances of the U.S. National Vegetation Classification. Ecological Monographs 79(2):173-199.

FGDC [Federal Geographic Data Committee]. 2008. Vegetation Classification Standard, FGDC-STD-005, Version 2. Washington, DC., USA. [http://www.fgdc.gov/standards/projects/FGDC-standards-projects/vegetation/NVCS_V2_FINAL_2008-02.pdf]

For additional information contact:

  • Implementation of the U.S. National Vegetation Classification Standard - Alexa McKerrow (amckerrow@usgs.gov)
  • NatureServe's Development of NVC Type Descriptions - Don Faber-Langendoen (don_faber- langendoen@natureserve.org)
  • Ecological Society of America's Review of the Type Descriptions Scott.Franklin@unco.edu
  • Federal Geographic Data Committee - Vegetation Subcommittee's Activities - Marianne Burke (mburke@fs.fed.us)
Sue Gawler authored two groups contributing to this description. Josh Cohen provided additional edits and the extended quoted text from Slaughter et al. (2007). Sean Basquill provided review comments.