Common (Translated Scientific) Name: Broadleaf Cattail - White Snakeroot - Rush species Marsh, Wet Meadow & Shrubland Macrogroup
Colloquial Name: Eastern North American Marsh, Wet Meadow & Shrubland
Hierarchy Level: Macrogroup
Type Concept: This largely freshwater wetland macrogroup encompasses shrub swamps, marshes, wet meadows and wet prairies of temperate and boreal eastern North America, north of the southern Atlantic and Gulf coastal plains and east of the Great Plains and Yukon Territory. It is dominated by graminoids (e.g., species of the genera Calamagrostis, Carex, Echinochloa, Glyceria, Juncus, Leersia, Schoenoplectus, Scirpus, Sparganium, Typha, Zizania), forbs (e.g., species of the genera Bidens, Eupatorium, Lobelia, Polygonum, Rumex, Sagittaria), and shrubs (e.g., species of Alnus, Cornus, Salix, Spiraea, Viburnum) in a widely variable composition and structure. This macrogroup also contains eastern inland saline meadows characterized by Atriplex patula, Juncus gerardii, and others. Freshwater marshes and shrub swamps occur in closed or open basins that are generally flat and shallow and are frequently to nearly always flooded. Water depths during high water periods range from a few centimeters to approximately 1 m. Stands assigned to this macrogroup are associated with lakes, ponds, slow-moving streams, non-forested seepages, and/or impoundments or ditches on mineral soils with or without a well-decomposed muck layer. This vegetation spans a wide range, from southeastern and south-central Canada southwest to the Great Lakes states and provinces, south to the Ozarks in Arkansas and east through the northern regions of the Gulf coast states to the southern Appalachian Mountains in Tennessee. It includes the Appalachian Mountain, Piedmont, and Interior Plateau regions, but not the Atlantic or Gulf coastal plains.
Diagnostic Characteristics: Saturated or seasonally flooded to semipermanently flooded freshwater emergent marshes, seepage wet meadows, or shrub swamps characterized by wetland herbs, e.g., species of the genera Calamagrostis, Carex, Echinochloa, Glyceria, Juncus, Leersia, Schoenoplectus, Scirpus, Sparganium, Typha, Zizania), forbs (e.g., species of the genera Bidens, Eupatorium, Lobelia, Polygonum, Rumex, Sagittaria), and wetland shrubs such as Alnus incana, Alnus serrulata, Cornus sericea, other Cornus spp., and Salix spp. The substrate is mineral soil or deep muck, but not peat.
Rationale for Nominal Species or Physiognomic Features: These are widespread dominants that span the range from deep marsh to wet meadow.
Classification Comments: This unit is geographically and hydrologically rather broad, and, ultimately, some subdivision may be warranted. Also Atlantic & Gulf Coastal Plain Wet Prairie & Marsh Macrogroup (M067) overlaps a great deal and is confusing because it is coastal, mostly, and this macrogroup (M069) is mostly non-coastal except for Northern & Mid-Atlantic Coastal Wetland Group (G752). The distinction between these two needs to be made very clear.
Similar NVC Types:
M303 Eastern-Southeastern North American Ruderal Marsh, Wet Meadow & Shrubland, note: monodominant stands of invasives, such as Phragmites australis or Typha angustifolia are present in some sites. Where they are mixed with natives they can be treated with M069.
M067 Atlantic & Gulf Coastal Plain Wet Prairie & Marsh, note: overlaps a great deal and is confusing because it is coastal, mostly, and M069 is mostly non-coastal except G752.
M071 Great Plains Marsh, Wet Meadow, Shrubland & Playa, note: has substantial overlap in species composition but vegetation of the Great Plains can be differentiated by marsh and wet meadow species that do not occur or are rare in the East, such as Beckmannia syzigachne, Calamagrostis stricta, Carex nebrascensis, Pascopyrum smithii, Scolochloa festucacea, Sporobolus airoides, and others.
M108 Eastern North American Freshwater Aquatic Vegetation, note:
M066 Atlantic & Gulf Coastal Fresh-Oligohaline Tidal Marsh, note:
Physiognomy and Structure: Physiognomy is widely variable among and often within sites, ranging from dense shrub swamp, to herbaceous wetland with varying but generally small amounts of shrub or tree sapling cover. Evergreens are generally absent or unimportant.
Floristics: These freshwater marshes and shrub swamps are characterized by a high diversity of species. Typha spp. and Schoenoplectus spp. are common and widespread, but a wide variety may be dominant in any single stand. Dominant shrubs include Alnus incana ssp. rugosa or Alnus serrulata, Cephalanthus occidentalis, Cornus spp., or Vaccinium corymbosum. Associates include Ilex verticillata, Myrica gale, Spiraea alba, Salix spp., and Viburnum nudum var. cassinoides. Many other graminoids or broad-leaved forbs can be found in these wetlands. Some of the common ones are Calamagrostis canadensis, Carex aquatilis, Carex lacustris, Carex pellita, Carex stricta, Dulichium arundinaceum, Eleocharis palustris, Juncus spp., Leersia oryzoides, Peltandra virginica, Pontederia cordata, Sagittaria latifolia, Schoenoplectus acutus, Schoenoplectus americanus, Schoenoplectus fluviatilis, Schoenoplectus tabernaemontani, Scirpus atrovirens, Scirpus cyperinus, Sparganium spp., Spartina pectinata, Zizania aquatica, and Zizania palustris. Along the drier margins of some sites where soils are more saturated than flooded, Calla palustris, Symplocarpus foetidus, and Thelypteris palustris can sometimes be found. The invasives Lythrum salicaria and Phragmites australis are present in some sites.
Dynamics: The dynamics of water levels are the most important factor in this vegetation, differentiating it from both the surrounding uplands and among the various alliances and associations comprising the macrogroup. Variation in rainfall patterns and in site drainage drives variation in duration of flooding. Wave and current action is typically minor, although especially strong storms may create large waves and/or currents that break up marsh vegetation. Prolonged drought or a lowering of the water table may lead to exposure of the soil and invasion by plants less tolerant of prolonged flooding. Fire is presumably naturally rare in this vegetation. Although they would naturally be exposed to fires in the surrounding uplands, standing water and lack of continuous fuel limit fires to the edges, except perhaps in early fall. Presumably important as a dynamic process is the migration of amphibians, which concentrate here for breeding. Ecosystem dynamics may be strongly affected by the suitability of surrounding uplands for amphibian adult habitat.
Geographic Range: This freshwater marsh macrogroup is found across temperate and boreal eastern North America, north of the southern Atlantic and Gulf coastal plains and east of the Great Plains and Yukon Territory. It stretches from eastern to central boreal Canada, from New England and New Brunswick, excluding the Atlantic Coastal Plain, west through the Great Lakes area to eastern North Dakota and northwestern Ontario, south to Missouri and east to the Southern Blue Ridge and Southern and Central Appalachians.
Nations: CA, US
States/Provinces: AB, AR, CT, DE, IA, IL, IN, KY, MA, MB, MD, ME, MI, MN, MO, NB, ND, NF, NH, NJ, NS, NY, OH, ON, PA, PE, QC, RI, SD, SK, TN, VA, VT, WI, WV
|US Forest Service Ecoregions (2007)|
Laurentian Mixed Forest Province
Confident or certain
Southwest Lake Superior Clay Plain Section
Confident or certain