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Macrogroup Detail Report: M029
Acer saccharinum - Platanus occidentalis - Celtis spp. Floodplain Forest Macrogroup

The U.S. National
Vegetation Classification
The macrogroup includes hardwood floodplain forests typically dominated by a combination of Acer negundo, Acer saccharinum, Celtis laevigata, Celtis occidentalis, Fraxinus pennsylvanica, Liquidambar styraciflua, Platanus occidentalis, Populus deltoides, and/or Ulmus americana. It occurs in the central, south-central, and north-central U.S. and extreme southern Ontario and Quebec in Canada.
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Translated Name:Silver Maple - American Sycamore - Hackberry species Floodplain Forest Macrogroup
Colloquial Name:Central Hardwood Floodplain Forest
This macrogroup encompasses north-temperate floodplain forests dominated by some combination of Acer negundo, Acer saccharinum, Celtis laevigata, Celtis occidentalis, Fraxinus pennsylvanica, Liquidambar styraciflua, Platanus occidentalis, Populus deltoides, and/or Ulmus americana. Associated trees include Acer rubrum, Betula nigra, and/or Liriodendron tulipifera. Common shrubs include Asimina triloba, Carpinus caroliniana, Cornus amomum, and Viburnum spp. Vines, including Parthenocissus spp., Toxicodendron radicans, and/or Vitis spp., are often abundant. The herb layer in the forested portions often features abundant spring ephemerals, giving way to a fern- or forb-dominated understory in many areas by mid-summer. This macrogroup occurs in eastern North America ranging from central Minnesota south to the Ozarks of Arkansas and Missouri east to New England and southern Canada. Some examples reach as far south as the plains of Alabama to Arkansas. Low-lying areas are underwater each spring; microtopography determines how long the various habitats are inundated. Reservoirs and conversion to agriculture have had a serious and negative effect on this macrogroup. Historically, drought, grazing, and fire influenced this macrogroup.
Deciduous forests with continuous or partial canopies in river floodplains. Acer negundo, Acer saccharinum, Celtis laevigata, Celtis occidentalis, Fraxinus pennsylvanica, Platanus occidentalis, Populus deltoides, and/or Ulmus americana are dominant. Betula nigra, Liriodendron tulipifera, and/or Liquidambar styraciflua are common associates in south-central examples.
Vegetation Hierarchy
Name:Database Code:Classification Code:
Class 1 Forest & Woodland C01 1
Subclass 1.B Temperate & Boreal Forest & Woodland S15 1.B
Formation 1.B.3 Temperate Flooded & Swamp Forest F026 1.B.3
Division 1.B.3.Na Eastern North American-Great Plains Flooded & Swamp Forest D011 1.B.3.Na
Macrogroup M029 Central Hardwood Floodplain Forest M029 1.B.3.Na.1
Group G652 Silver Maple - Green Ash - Sycamore Floodplain Forest G652 1.B.3.Na.1.a
Group G673 Silver Maple - Sugarberry - Sweetgum Floodplain Forest G673 1.B.3.Na.1.b
Silver Maple - Green Ash - Black Ash Floodplain Forest Group (G653) was moved to Laurentian-Acadian-North Atlantic Coastal Flooded & Swamp Forest Macrogroup (M504) per comments from Canadian ecologists. These are floodplain alliances with species that are more common in the central parts of the United States. Further review is needed to see if these northern expressions of Acer saccharinum flooded forests are outliers of this macrogroup or have enough northern associates to fit comfortably with other northern flooded and swamp forest types in M504. Eastern North American floodplain forests contain a diverse suite of dominant tree species with wide ranges, and they resist subdivision into neat groups and alliances. Some readjustment may be necessary. Further review is needed to ascertain if this is the correct way to separate these floodplain groups and alliances Into the appropriate macrogroups.

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Short Citation:
  • Faber-Langendoen et al. 2017a
States/Provinces:AL, AR, CT, DE, FL, GA, IA, IL, IN, KS, KY, LA, MA, MD, ME, MI, MN, MO, MS, NB, NC, ND, NE, NH, NJ, NY, OH, OK, ON, PA, QC, SC, TN, TX, VA, VT, WI, WV
Nations:CA, US
Range:This macrogroup is found across a large area of the northeastern, midwestern, and southeastern U.S. and southern Canada. It ranges from southern New England and Canada south and west through Minnesota and Iowa and south to the Interior Low Plateau of Ohio, Indiana, Illinois and Kentucky and the Ozarks of Arkansas and Missouri, and the Crosstimbers of Oklahoma. It extends south into the upper plains from Alabama to Arkansas.
US Forest Service Ecoregions
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These forests have continuous or partial canopies and are often characterized by multi-stemmed trees as stems resprout after catastrophic disturbance. Vines may be abundant. Shrub cover varies; in many of these forests, it is sparse, giving a parklike appearance. Herb cover also varies, and herbs are either perennials that are disturbance-tolerant or annuals.
The most common trees in these forests through most of the range are Acer negundo, Acer saccharinum, Celtis occidentalis, Fraxinus pennsylvanica, Platanus occidentalis, Populus deltoides, and/or Ulmus americana. Celtis laevigata and/or Liquidambar styraciflua are important constituents in the southern and midwestern portions of the range. Associated tree species include Acer rubrum, Betula nigra, Carya cordiformis, Carya illinoinensis, and/or Ulmus rubra. In portions of the floodplain that are flooded for shorter durations, associates include Acer saccharum, Carya ovata, Fraxinus americana, Juglans nigra, Prunus serotina, Quercus alba, Quercus macrocarpa, and Quercus rubra. Parthenocissus quinquefolia, Toxicodendron radicans, and Vitis spp. are common vines. Characteristic shrubs include Asimina triloba, Carpinus caroliniana, Cornus amomum, Cornus drummondii, Cornus foemina, Lindera benzoin, and Viburnum nudum. Typical herbs vary somewhat with geography. Some common species include Boehmeria cylindrica, Elymus virginicus, Impatiens capensis, Laportea canadensis, Matteuccia struthiopteris, and Verbesina alternifolia. Spring ephemerals such as Allium tricoccum, Claytonia spp., Erythronium americanum, Mertensia virginica, and Sanguinaria canadensis may be abundant.
This macrogroup is best expressed along medium to large rivers but may be found along low-gradient reaches of smaller rivers and streams where a flat floodplain develops. A variety of alluvial soil types may be found within the floodplain from very well-drained sandy substrates to very dense clays. It is this variety of substrates in combination with different flooding regimes that creates the mix of vegetation.
Flooding is the primary dynamic process, and many stands are flooded annually. Sediment accretion outpaces erosional processes in this macrogroup. Agriculture has converted much of this macrogroup to agricultural land, sometimes (particularly in the lower portions of the floodplain) involving adding drainage. Conversion to agriculture greatly reduced its abundance and continuity of occurrences (or fragmenting occurrences). Drought, grazing, and fire have all had historical influence. Reservoirs have had a serious and negative effect on vegetation that represents this macrogroup.
S. Menard      Version Date: 15Oct2014

  • 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]

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:
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About this document
This document contains type descriptions at the Macrogroup 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 (