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A3714 Acer saccharum - Tilia americana Mesic Floodplain Forest Alliance

Type Concept Sentence: Varying canopy dominants typically include some combination of Acer saccharum, Tilia americana, Fraxinus spp., Fraxinus pennsylvanica, Prunus serotina, Quercus rubra, and Ulmus americana. This alliance ranges across the northeastern United States and the St. Lawrence and Atlantic regions of Canada along slightly elevated alluvial terraces and active floodplains, streams with small watersheds, high-gradient or submontane portions of major rivers.

Common (Translated Scientific) Name: Sugar Maple - American Basswood Mesic Floodplain Forest Alliance

Colloquial Name: Sugar Maple - American Basswood Mesic Floodplain Forest

Hierarchy Level:  Alliance

Type Concept: The canopy dominants can vary from site to site but are usually some combination of Acer saccharum, Tilia americana, Quercus rubra, Ulmus americana, Fraxinus americana, Fraxinus pennsylvanica, and Prunus serotina. Shrubs are typically minor. The herbaceous layer is typically diverse and often features Matteuccia struthiopteris along with a variety of graminoids, ferns and forbs. This alliance ranges across the northeastern United States and the St. Lawrence and Atlantic regions of southern Canada. It occurs along slightly elevated alluvial terraces and active floodplains, streams with small watersheds (<2 square miles), high-gradient or submontane portions of major rivers. Soils range from alluvial sands to sand and silt loams.

Diagnostic Characteristics: Mesic floodplain forests dominated by a combination Acer saccharum, Tilia americana, Quercus rubra, Ulmus americana, and Fraxinus spp. Diagnostics that distinguish this type from central floodplains in the northeast and north-central United States are needed.

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: This alliance is more mesic than the other alliance in this group (G653). It can be difficult to distinguish from upland maple forests or lower terrace floodplain forests. This alliance may need to move to a more mesic group. A similar alliance occurs within ~Silver Maple - Green Ash - Sycamore Floodplain Forest Group (G652)$$. More review of this separation is needed. As defined, this type is primarily found in the Acadian and St. Lawrence regions of eastern Canada, and southward into Lower New England, the Allegheny Plateau and lower Great Lakes. But it may be that the southward part is a better fit with ~Silver Maple - Sugarberry - Sweetgum Floodplain Forest Group (G673)$$, because of the presence of Platanus occidentalis, Salix nigra, and other central hardwood floodplain species. And it could be expected in the western Great Lakes states of Michigan, Wisconsin, and northwest Minnesota [but see also ~Acer saccharinum Upper Great Lakes Low Floodplain Forest (CEGL005489)$$].

Similar NVC Types: No Data Available
note: No Data Available
Physiognomy and Structure: Deciduous floodplain forests with closed to somewhat open canopy and a rich, well-developed herb layer.

Floristics: Canopy dominants can vary from site to site, but are usually some combination of Acer saccharum, Fraxinus americana, Fraxinus pennsylvanica, Prunus serotina, Quercus rubra, Tilia americana, and Ulmus americana. Other canopy associates can include Acer rubrum, Acer saccharinum, Betula alleghaniensis, Carpinus caroliniana, Carya ovata, Fraxinus nigra, and Juglans cinerea. Shrubs are occasional, but typically do not form high cover and may include Corylus americana, Prunus virginiana, and Viburnum lentago. Vines such as Parthenocissus spp., Toxicodendron radicans, or Vitis spp. may be locally common. The herb layer is typically rich and well-developed and seasonally variable, with spring ephemerals giving way to taller ferns, graminoids, and forbs. The herb layer often features Matteuccia struthiopteris and a mixture of other ferns, forbs, and graminoids. Characteristic species include Ageratina altissima (= Eupatorium rugosum), Allium spp., Asarum canadense, Athyrium filix-femina, Caulophyllum thalictroides, Carex spp., Danthonia spicata, Elymus spp., Laportea canadensis, Onoclea sensibilis, Sanguinaria canadensis, and Solidago spp. in addition to abundant spring ephemerals in the early growing season. Non-native and invasive species are often present and may include Lonicera morrowii and Rhamnus cathartica.

Dynamics:  Forests are flooded during spring runoff periods and perhaps during other peak floods and less regularly inundated than the soils supporting silver maple floodplain forests.
Environmental Description:  It occurs along slightly elevated alluvial terraces and active floodplains, streams with small (<2 square mile) watersheds, high-gradient or submontane portions of major rivers. Soils range from alluvial sands to sand and silt loams and range from well-drained to poorly drained with very shallow or no organic horizons. These soils are typically less regularly inundated than the soils supporting silver maple floodplain forests. Even with the floodplain setting, some examples may be considered uplands rather than wetlands.
Geographic Range: This alliance is found across northeastern U.S. and the St. Lawrence and Atlantic regions of Canada.

Nations: CA,US

States/Provinces:  CT, MA, MD, ME, NB, NH, NJ, NY, PA, QC, VT


Confidence Level: Moderate

Confidence Level Comments: No Data Available
Grank: GNR

Greasons: No Data Available
Type Name Database Code Classification Code
Class 1 Forest & Woodland Class C01 1
Subclass 1.B Temperate & Boreal Forest & Woodland Subclass S15 1.B
Formation 1.B.3 Temperate Flooded & Swamp Forest Formation F026 1.B.3
Division 1.B.3.Na Eastern North American-Great Plains Flooded & Swamp Forest Division D011 1.B.3.Na
Macrogroup 1.B.3.Na.3 <i>Tsuga canadensis - Fraxinus nigra - Larix laricina</i> Flooded & Swamp Forest Macrogroup M504 1.B.3.Na.3
Group 1.B.3.Na.3.a Silver Maple - Green Ash - Black Ash Floodplain Forest Group G653 1.B.3.Na.3.a
Alliance A3714 Sugar Maple - American Basswood Mesic Floodplain Forest Alliance A3714 1.B.3.Na.3.a
Association CEGL006114 Sugar Maple - Ash species - American Basswood / Ostrich Fern - White Snakeroot Floodplain Forest CEGL006114 1.B.3.Na.3.a
Association CEGL006405 American Basswood - Sugar Maple - Black Maple / Canadian Woodnettle Floodplain Forest CEGL006405 1.B.3.Na.3.a
Association CEGL006504 Sugar Maple / Hophornbeam / Bearded Shorthusk Floodplain Forest CEGL006504 1.B.3.Na.3.a
Concept Lineage: This alliance includes associations from the northernmost distribution of A.302.

Predecessors: No Data Available

Obsolete Names: No Data Available

Obsolete Parents: No Data Available
Synonomy: >< Sugar Maple: 27 (Eyre 1980)
Concept Author(s): S. Menard, in Faber-Langendoen et al. (2013)

Author of Description: S. Menard

Acknowledgements: No Data Available

Version Date: 12-18-14
  • Eyre, F. H., editor. 1980. Forest cover types of the United States and Canada. Society of American Foresters, Washington, DC. 148 pp.
  • Faber-Langendoen, D., J. Drake, M. Hall, G. Kittel, S. Menard, C. Nordman, M. Pyne, M. Reid, M. Russo, K. Schulz, L. Sneddon, K. Snow, and J. Teague. 2013-2019b. Screening alliances for induction into the U.S. National Vegetation Classification: Part 1 - Alliance concept review. NatureServe, Arlington, VA.
  • Faber-Langendoen, D., and Midwest State Natural Heritage Program Ecologists. 1996. Terrestrial vegetation of the midwest United States. International classification of ecological communities: Terrestrial vegetation of the United States. The Nature Conservancy, Arlington, VA.