Invalid Unit Specified
G189 Eriophorum virginicum - Impatiens spp. - Symplocarpus foetidus Seep Group

The U.S. National
Vegetation Classification
Type Concept Sentence: These are herbaceous-dominated seepage-fed wetlands found on gentle slopes in temperate northeastern North America from Maryland and Pennsylvania north to Maine, Vermont, Wisconsin, and into adjacent Canada. This vegetation is primarily dominated by tall and short forbs, as well as by graminoids and Sphagnum mosses in some component associations.
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Common (Translated Scientific) Name: Tawny Cottongrass - Jewelweed species - Skunk-cabbage Seep Group
Colloquial Name: North-Central & Northeastern Seep
Hierarchy Level: Group
Type Concept: This group contains primarily herbaceous-dominated seep vegetation of the north-central and northeastern United States from Maryland and Pennsylvania north to Maine, Vermont, Wisconsin, and into adjacent Canada. This vegetation is primarily dominated by tall and short forbs, as well as by graminoids and Sphagnum mosses in some associations. These seepage-fed wetlands are found on gentle slopes. Examples are linear, non-peaty, non-sphagnous, often rocky, groundwater slope wetlands that are embedded in an upland forest setting. Some smaller examples may be nearly or fully shaded by overhanging trees rooted in the adjacent forest, but others are open. Stands of this group are dominated by a wetland flora, but with a lack of species characteristic of floodplains and true bogs (some bog-related species may occasionally be present). Trees may be present on the edges of stands, or often overhanging, but are not characteristic. Shrub species are typically sparse and most typically mesophytic, rather than obligate wetland species. They may form dense zones around the edge but are not characteristic. The herb layer is generally well-developed, and is usually dominated either by characteristic forbs such as Chelone spp., Impatiens capensis, Impatiens pallida, Rudbeckia laciniata, and Symplocarpus foetidus, and/or with presence of Carex spp. and other graminoids, including Eriophorum virginicum and Glyceria striata. In addition, Sphagnum spp. may occur in a minority of examples, but it is more characteristic of vegetation in the other groups within this macrogroup.
Diagnostic Characteristics: These are forb- or graminoid-dominated seepage wetlands of the north-central and northeastern United States ranging into adjacent Canada.
Rationale for Nominal Species or Physiognomic Features:
Classification Comments: The memberships of the clearly related Central & Southern Appalachian Seep Group (G184) and this group (G189) have been revised along (more-or-less) clear biogeographic lines. G184 is now "Central and Southern Appalachian" in its affinity and membership, and the range of G189 is "North-Central and Northeastern." This hopefully resolves some of the issues with the former concepts for these groups. Clay Seeps Sparse Vegetation (CEGL005163) is an outlier both in geography and environmental setting, but does not appear to fit well in any other existing group. In Atlantic Canada, this type may well occur, especially along the coast, but further review is needed (S. Basquill pers. comm. 2015).
Similar NVC Types:
G183 Midwest Prairie Alkaline Fen, note:
G184 Central & Southern Appalachian Seep, note:
G805 North-Central Interior & Appalachian Alkaline Fen, note:
Physiognomy and Structure: Stands of this group are typically dominated by tall and short forbs, as well as by graminoids and Sphagnum mosses in some associations.
Floristics: Stands of this group are typically dominated by tall and short wetland forbs or by graminoids, and normally with a lack of species characteristic of floodplains and true bogs (but some bog-related species may be present). Trees may be present on the edges of stands, often overhanging, but are not characteristic. Shrub species are typically sparse and most typically mesophytic, rather than obligate wetland species. They may form dense zones around the edge but are not characteristic. The herb layer is generally well-developed, and is usually dominated either by characteristic forbs such as Chelone spp., Impatiens capensis, Impatiens pallida, Rudbeckia laciniata, and Symplocarpus foetidus, and/or with presence of Carex spp. and other graminoids, including Eriophorum virginicum and Glyceria striata.
Dynamics: The presence of seepage is the primary environmental characteristic of stands of this group. Long-term droughts that would affect seepage flow are presumed to have an effect on the vegetation, but this has not been documented. Soil wetness may limit recruitment of most tree and shrub seedlings to drier embedded microsites, making canopy gaps persist longer than in adjacent forests and creating and sustaining the openings where this vegetation occurs. Fires may penetrate from adjacent forests, but only in the driest conditions are they likely to be intense enough to have much effect. Seeps are fairly permanent features of the landscape, but may potentially be created, destroyed, or altered in extent because of changes in groundwater flow, stream entrenchment or headward erosion, mass movement on slopes, or long-term climatic cycles. Examples are often left undisturbed when surrounding forests are logged. Effects of logging on water infiltration or surface flow may have significant indirect effects.
Environmental Description: This vegetation occurs in small patches where seepage creates permanent or seasonally saturated soil conditions. Wetness may vary substantially over short distances in response to amounts of seepage, flow, and pooling by topography or the presence of an impermeable substrate. Stands of the group occur over a wide elevational range, from low and moderate elevations northward nearly to the highest peaks of the Southern Appalachians. Landforms are usually concave slopes but may be convex slopes or even (rarely) ridgetop gaps. This vegetation is almost never found on flat valley bottoms, though it may be found on their edges. Soils are usually saturated mineral soils, rather than peats or mucks, and may be residual or colluvial, and shallow to deep.

Climate: This vegetation is favored by a cool-temperate climate, in which cool temperatures and high rainfall make more water available, thereby making seepage flow more reliable. Soil/substrate/hydrology: This vegetation occurs in small patches where seepage creates permanent or seasonal saturated soil conditions. Soils are usually saturated mineral soils, rather than peats or mucks. Soil wetness may limit recruitment of most tree and shrub seedlings to drier microsites, making canopy gaps persist longer than in adjacent forests and creating and sustaining the openings where this vegetation is found. Wetness may vary substantially over short distances in response to amounts of seepage, flow, and pooling by topography or impermeable substrate.
Geographic Range: This vegetation ranges throughout the north-central and northeastern United States from Maryland and Pennsylvania north to Maine, Vermont, Wisconsin, and into adjacent Canada.
Nations: CA, US
States/Provinces: CT, DC, DE, IA, IL, MA, MD, ME, MI, MN, NB?, NH, NJ, NS?, NY, OH, PA, QC?, RI, VA, VT, WI, WV
US Forest Service Ecoregions (2007)
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Plot Analysis Summary:
Confidence Level: Low
Confidence Level Comments:
Grank: GNR
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Concept Author(s): M. Pyne, in Faber-Langendoen et al. (2011)
Author of Description: M. Pyne, S.C. Gawler, M. Pyne and D. Faber-Langendoen
Acknowledgements: Sean Basquill
Version Date: 19May2015
References:
  • 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]