Invalid Unit Specified
Group Detail Report: G752
Northern & Mid-Atlantic Coastal Wetland Group

The U.S. National
Vegetation Classification
This group comprises wetlands of maritime and coastal regions of the northeast and mid-Atlantic states; it includes small-patch wetlands generally referred to as "interdunal swales" and other non-forested wetlands of this region.
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Translated Name:Northern & Mid-Atlantic Coastal Wetland Group
Colloquial Name:Northern & Mid-Atlantic Coastal Wetland
This group comprises small-patch non-forested wetlands exclusive of those that are tidally flooded in maritime and coastal areas of the northeast and mid-Atlantic states. It includes small-patch wetlands generally known as "interdunal swales" as well as other non-forested coastal wetlands that are not tidally flooded. Characteristic species include Fimbristylis castanea, Morella cerifera, Morella pensylvanica, Panicum virgatum, Schoenoplectus pungens, Vaccinium corymbosum, Vaccinium macrocarpon, and species of Juncus.
Small-patch non-forested wetlands that are not tidally flooded, restricted to maritime or coastal settings in the northeast and mid-Atlantic regions. They are common in maritime dune systems across the range, or on morainal deposits in coastal New England.
No Data Available
Synonomy: < Panicum virgatum wetland association (Heckscher et al. 1995)
< Vaccinietum macrocarponi (Conard 1935)
< Brackish Interdunal Swales (NYNHP 2013v)
>< Coastal interdunal swale (FNAI 1992b)
< Interdune swales and ponds (Fleming et al. 2013)
< Mesic shrub zone (Higgins et al. 1971)

Related Type Name:

Short Citation:
  • Conard 1935
  • Faber-Langendoen et al. 2017a
  • Fleming et al. 2013
  • FNAI 1992b
  • Heckscher et al. 1995
  • Higgins et al. 1971
  • NYNHP 2013v
  • Swain and Kearsley 2011
States/Provinces:CT, DE, MA, MD, ME, NC, NH, RI, SC, VA
Nations:CA?, US
Range:This group ranges from Maine south along the immediate coast to South Carolina discontinuously to Florida. This group may also occur in southern Canada.
US Forest Service Ecoregions
Domain Name:
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This group ranges from herbaceous-dominated to shrub-dominated. Generally the vegetation is well-developed with high cover, especially later in the growing season. Vegetation of this group is best developed in late summer.
Interdunal swales of the glaciated region are commonly dominated by Vaccinium macrocarpon, with associates including Cladium mariscoides and species of Rhynchospora. They generally lack Chamaedaphne calyculata, but support other species often found in bogs, including species of Drosera, Sphagnum, and Pogonia ophioglossoides. In the Mid-Atlantic, interdunal swales are generally more floristically diverse, often characterized by Fimbristylis castanea, Hibiscus moscheutos, Juncus canadensis, Juncus dichotomus, Pluchea odorata, Schoenoplectus pungens, and Thelypteris palustris. Other wetlands support shrub thickets dominated by Cephalanthus occidentalis, Morella cerifera (in the mid-Atlantic), Morella pensylvanica (characteristic of ponds on moraine landscapes in New England), and Vaccinium corymbosum.
These small-patch wetlands occur in shallow, seasonally flooded basins occurring in hollows of major dune systems. They also occur on the shores of larger, sometimes deeper ponds that occur on morainal deposits in the glaciated part of the region.
Groundwater and rainwater are the only sources of inundation, and water levels decrease or standing water may absent later in the growing season. Some interdunal swales are slightly saline as a result of occasional overwash.
59:C, 63:C, 82:C, 84:C
L.A. Sneddon      Version Date: 13May2015

  • Conard, H. S. 1935. The plant associations of central Long Island. The American Midland Naturalist 16:433-516.
  • 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]
  • Fleming, G. P., K. D. Patterson, K. Taverna, and P. P. Coulling. 2013. The natural communities of Virginia: Classification of ecological community groups. Second approximation. Version 2.6. Virginia Department of Conservation and Recreation, Division Richmond, VA. []
  • FNAI [Florida Natural Areas Inventory]. 1992b. Natural community classification. Unpublished document. The Nature Conservancy, Florida Natural Areas Inventory, Tallahassee. 16 pp.
  • Heckscher, C. M., W. A. McAvoy, and K. Clancy. 1995. Biological assessment of the Milford Neck Preserve. Division of Fish and Wildlife, Department of Natural Resources and Environmental Control, Delaware Natural Heritage Program, Smyrna, DE. 29 pp.
  • Higgins, E. A. T., R. D. Rappleye, and R. G. Brown. 1971. The flora and ecology of Assateague Island. University of Maryland Experiment Station Bulletin A-172. 70 pp.
  • NYNHP [New York Natural Heritage Program]. 2013v. Online conservation guide for Brackish Interdunal Swales. New York Natural Heritage Program, Albany, NY. []
  • Swain, P. C., and J. B. Kearsley. 2011. Classification of the natural communities of Massachusetts. Version 1.4. Natural Heritage & Endangered Species Program, Massachusetts Division of Fisheries and Wildlife, Westborough, MA. []

USNVC Credits: Detailed Description of the National Vegetation Classification Types

Date Accessed:

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 Group 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:

U.S. Government
  • Department of Agriculture (USDA)
  • 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)
  • National Oceanic and Atmospheric Administration (NOAA)
  • National Marine Fisheries Service (NMFS)
  • U.S. Army Corps of Engineers (USACE)
  • U.S. Navy (NAVY)
  • Bureau of Land Management (BLM)
  • Fish and Wildlife Service (FWS)
  • National Park Service (NPS)
  • U.S. Geological Survey (USGS)
  • Environmental Protection Agency (EPA)
  • National Aeronautics and Space Administration (NASA)
Non U.S. Government
  • NatureServe (NS)
  • Ecological Society of America (ESA)

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 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. []

For additional information contact:

  • Implementation of the U.S. National Vegetation Classification Standard - Alexa McKerrow (
  • NatureServe's Development of NVC Type Descriptions - Don Faber-Langendoen (don_faber-
  • Ecological Society of America's Review of the Type Descriptions
  • Federal Geographic Data Committee - Vegetation Subcommittee's Activities - Marianne Burke (