Common (Translated Scientific) Name: Gray Alder / Prairie Cordgrass - Sedge species Laurentian-Acadian Riverscour Vegetation Group
Colloquial Name: Laurentian-Acadian Riverscour Vegetation
Hierarchy Level: Group
Type Concept: This rivershore group occurs in the northeastern United States, adjacent southeastern Canada, and the western Great Lakes along rivers where flooding and ice-scour affect the vegetation. Vegetation is often patchy and can be dominated by shrubs, graminoids, or forbs. A wide variety of species can be common, including Alnus incana, Alnus viridis, Cornus sericea, Dasiphora fruticosa ssp. floribunda, Argentina anserina, Apocynum cannabinum, Carex stricta, Deschampsia caespitosa, Desmodium canadense, Iris versicolor, Parnassia glauca, Rhynchospora capillacea, Rhynchospora capitellata, Spartina pectinata, and Thalictrum pubescens. Sites occur on sand, gravel, cobble, or bedrock and may be calcareous.
Diagnostic Characteristics: This group is found along rivers where a rivershore of sandy, gravelly, or rocky substrate supports clumps of shrubs, graminoids, or forbs. Sites are frequently affected by flooding or ice-scour but are not flooded for most of the growing season.
Rationale for Nominal Species or Physiognomic Features:
Classification Comments: No Data Available
Similar NVC Types:
Physiognomy and Structure: This group has a widely variable physiognomy with bare patches of exposed alluvium, patches of dense vegetation, and intermediate areas. Dominant species can be shrubs, forbs, or graminoids. Trees are absent or very sparse.
Floristics: Vegetation in this group can have variable cover of shrubs, forbs, and graminoids. Common shrubs include Alnus incana, Alnus viridis, Cornus sericea, Dasiphora fruticosa ssp. floribunda, Prunus pumila, and Salix eriocephala. Herbaceous species can include Argentina anserina, Apocynum cannabinum, Campanula rotundifolia, Carex aurea, Carex flava, Carex garberi, Carex hystericina, Carex stricta, Deschampsia caespitosa, Desmodium canadense, Doellingeria umbellata, Iris versicolor, Liparis loeselii, Lobelia kalmii, Marshallia grandiflora, Parnassia glauca, Rhynchospora capillacea, Rhynchospora capitellata, Spartina pectinata, Triantha glutinosa, and Thalictrum pubescens.
Dynamics: Flooding and ice-scour can remove vegetation and rearrange soil.
Environmental Description: This group occurs on the shores of rivers where flooding and ice-scour impact the vegetation. Soil is patchy and often poorly developed. The substrate is sand, gravel, cobble, or bedrock. Groundwater seepage occurs in some examples and maintains a more saturated soil condition. Some sites are calcareous due to seepage of calcareous groundwater or occurring on calcareous substrates.
Geographic Range: This group can be found in the northeastern United States and southeastern Canada as well as in scattered occurrences in the western Great Lakes area.
Nations: CA, US
States/Provinces: CT, MA, ME, MI, NB, NH, NJ, NS, NY, ON, PA?, QC, VT, WI, WV
|US Forest Service Ecoregions (2007)|
Northeastern Mixed Forest Province
Confident or certain
Lower New England Section
Confident or certain
Confidence Level: Moderate
Confidence Level Comments:
Synonomy: > Calcareous Riverside Seep (Thompson and Sorenson 2000)
> Laurentian River Beach (Gawler and Cutko 2010)
Concept Author(s): D. Faber-Langendoen and L. Sneddon, in Faber-Langendoen et al. (2014)
Author of Description: J. Drake
Version Date: 20May2015
- 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]
- Gawler, S. C., and A. Cutko. 2010. Natural landscapes of Maine: A classification of vegetated natural communities and ecosystems. Maine Natural Areas Program, Department of Conservation, Augusta.
- Sperduto, D. D., and W. F. Nichols. 2004. Natural communities of New Hampshire: A guide and classification. New Hampshire Natural Heritage Bureau, DRED Division of Forests and Lands, Concord. 242 pp.
- Thompson, E. H., and E. R. Sorenson. 2000. Wetland, woodland, wildland: A guide to the natural communities of Vermont. The Nature Conservancy and the Vermont Department of Fish and Wildlife. University Press of New England, Hanover, NH. 456 pp.