Great Lakes-Acadian Floodplain Forest

EVT 9117Laurentian-Acadian Floodplain Forest
CES201.587GNRTreeRiparian
Summary
This system encompasses north-temperate floodplains in the northeastern and north-central U.S. and adjacent Canada at the northern end of the range of silver maple. They occur along medium to large rivers where topography and process have resulted in the development of a complex of upland and wetland temperate alluvial vegetation on generally flat topography. This complex includes floodplain forests, with Acer saccharinum characteristic, as well as herbaceous sloughs and shrub wetlands. In areas subject to more scour, sparse non-wetland vegetation may develop on sandbars or exposed rock. Most areas are underwater each spring; microtopography determines how long the various habitats are inundated. Associated trees include Acer rubrum and Carpinus caroliniana, the latter frequent but never abundant. On terraces or in more calcareous areas, Acer saccharum or Quercus rubra may be locally prominent, with Betula alleghaniensis and Fraxinus spp. Salix nigra is characteristic of the levees adjacent to the channel. Common shrubs include Cornus amomum and Viburnum spp. The herb layer in the forested portions often features abundant spring ephemerals, giving way to a fern-dominated understory in many areas by mid-summer. Non-forested wetlands associated with these systems include shrub-dominated and graminoid-herbaceous vegetation.
Source: NatureServe Explorer
Distribution
Central and northern New England and adjacent Canada west to the Great Lakes.
Source: NatureServe Explorer
Ecologically Associated Plant Species

Plant species that characterize this ecosystem type, organized by vegetation stratum. These are species ecologically associated with the ecosystem, not confirmed present in any specific area.

Tree canopy

Acer rubrum, Acer saccharinum, Acer saccharum, Betula alleghaniensis, Quercus rubra, Ulmus americana

Shrub/sapling (tall & short)

Carpinus caroliniana, Cornus amomum, Salix nigra

Herb (field)

Allium tricoccum var. tricoccum, Boehmeria cylindrica, Clematis virginiana, Erythranthe michiganensis, Matteuccia struthiopteris, Onoclea sensibilis
Source: NatureServe Ecological System assessment
Ecologically Associated Animals (13)

Animal species ecologically associated with this ecosystem type based on NatureServe assessment. These are species whose habitat requirements overlap with this ecosystem, not confirmed present in any specific roadless area.

Mammals (3)

Common NameScientific NameG-Rank
American BeaverCastor canadensisG5
Indiana MyotisMyotis sodalisG2
American MinkNeogale visonG5

Birds (5)

Common NameScientific NameG-Rank
Whooping CraneGrus americanaG1
Hairy WoodpeckerLeuconotopicus villosusG5
Black-capped ChickadeePoecile atricapillusG5
White-breasted NuthatchSitta carolinensisG5
Barred OwlStrix variaG5

Reptiles (1)

Common NameScientific NameG-Rank
Kirtland's SnakeClonophis kirtlandiiG2

Amphibians (1)

Common NameScientific NameG-Rank
Northern Leopard FrogLithobates pipiensG5

Butterflies & Moths (1)

Common NameScientific NameG-Rank
Ostrich Fern Borer MothPapaipema sp. 2 nr. pterisiiG3G4

Insects (2)

Common NameScientific NameG-Rank
Sioux SnaketailOphiogomphus smithiG2G3
Hine's EmeraldSomatochlora hineanaG2G3
Source: NatureServe Ecological System assessment
At-Risk Species Associated with this Ecosystem (7)

Species with conservation concern that are ecologically associated with this ecosystem type. G-Rank indicates global conservation status: G1 (critically imperiled) through G5 (secure). ESA status indicates U.S. Endangered Species Act listing.

Common NameScientific NameG-RankESA Status
Kirtland's SnakeClonophis kirtlandiiG2--
Michigan MonkeyflowerErythranthe michiganensisG1Endangered
Whooping CraneGrus americanaG1Endangered; Experimental population, non-essential
Indiana MyotisMyotis sodalisG2Endangered
Sioux SnaketailOphiogomphus smithiG2G3--
Ostrich Fern Borer MothPapaipema sp. 2 nr. pterisiiG3G4--
Hine's EmeraldSomatochlora hineanaG2G3Endangered
Source: NatureServe Ecological System assessment
Component Associations (17)

Plant community associations that occur within this ecological system. Associations are the finest level of the U.S. National Vegetation Classification (USNVC) and describe specific, repeating assemblages of plant species. Each association represents a distinct community type that may be found where this ecosystem occurs.

NameG-Rank
Acer rubrum - Abies balsamea / Viburnum nudum var. cassinoides Floodplain Forest NatureServe
Acer rubrum - Prunus serotina / Cornus amomum Floodplain Forest NatureServe
Acer (rubrum, saccharinum) - Fraxinus pennsylvanica / Ilex verticillata / Osmunda regalis Floodplain Forest NatureServe
Acer saccharinum / Onoclea sensibilis - Boehmeria cylindrica Floodplain Forest NatureServe
Acer saccharinum - (Populus deltoides) / Matteuccia struthiopteris - Laportea canadensis Floodplain Forest NatureServe
Acer saccharum - Fraxinus spp. - Tilia americana / Matteuccia struthiopteris - Ageratina altissima Floodplain Forest NatureServe
Acer saccharum / Ostrya virginiana / Brachyelytrum erectum Floodplain Forest NatureServe
Alnus incana - Cornus spp. / Clematis virginiana Alluvial Shrub Swamp NatureServe
Andropogon gerardii - Campanula rotundifolia - Solidago simplex Riverscour NatureServe
Calamagrostis canadensis - Scirpus spp. - Dulichium arundinaceum Wet Meadow NatureServe
Cephalanthus occidentalis - Decodon verticillatus Shrub Swamp NatureServe
Hudsonia tomentosa - Paronychia argyrocoma Riverscour Dwarf-shrubland NatureServe
Laurentian Bedrock-Boulder Rivershore Vegetation NatureServe
Laurentian Cobble-Gravel Rivershore Vegetation NatureServe
Prunus pumila var. depressa / Deschampsia cespitosa Riverscour Wet Meadow NatureServe
Spartina pectinata - Muhlenbergia richardsonis - Sporobolus heterolepis - Oligoneuron album - Euthamia graminifolia Riverscour Pavement NatureServe
Vaccinium spp. / Danthonia spicata - Solidago puberula Shoreline Outcrop NatureServe
State Conservation Ranks (7)

Subnational conservation status ranks (S-ranks) assigned by Natural Heritage Programs in each state where this ecosystem occurs. S1 indicates critically imperiled at the state level, S2 imperiled, S3 vulnerable, S4 apparently secure, and S5 secure. An ecosystem may be globally secure but imperiled in specific states at the edge of its range.

StateS-Rank
MESNR
MISNR
MNSNR
NHSNR
NYSNR
VTSNR
WISNR
Methodology and Data Sources

Ecosystem classification: Ecosystems are classified using the LANDFIRE 2024 Existing Vegetation Type (EVT) layer, mapped to NatureServe Terrestrial Ecological Systems via a curated crosswalk. Each EVT is linked to the USNVC (U.S. National Vegetation Classification) hierarchy through pixel-level co-occurrence analysis of LANDFIRE EVT and NatureServe IVC Group rasters across all roadless areas.

Vegetation coverage: Coverage percentages and hectares are derived from zonal statistics of the LANDFIRE 2024 EVT raster intersected with roadless area boundaries.

Ecosystem narratives and community species: Sourced from the NatureServe Explorer API, representing professional ecological assessments of vegetation composition, environmental setting, dynamics, threats, and characteristic species assemblages.

IVC hierarchy: The International Vegetation Classification hierarchy is sourced from the USNVC v3.0 Catalog, providing the full classification from Biome through Association levels.

Component associations: Plant community associations listed as components of each NatureServe Ecological System. Association data from the NatureServe Explorer API.

State ranks: Conservation status ranks assigned by NatureServe member programs in each state where the ecosystem occurs.