Ecological dynamics
[Caveat: The vegetation information contained in this section and is only provisional, based on concepts, not yet validated with field work.*]
The vegetation groupings described in this section are based on the terrestrial ecological system classification and vegetation associations developed by NatureServe (Comer 2003). Terrestrial ecological systems are specifically defined as a group of plant community types (associations) that tend to co-occur within landscapes with similar ecological processes, substrates, and/or environmental gradients. They are intended to provide a classification unit that is readily mappable, often from terrain and remote imagery, and readily identifiable by conservation and resource managers in the field. A given system will typically manifest itself in a landscape at intermediate geographic scales of tens-to-thousands of hectares and will persist for 50 or more years. A vegetation association is a plant community that is much more specific to a given soil, geology, landform, climate, hydrology, and disturbance history. It is the basic unit for vegetation classification and recognized by the US National Vegetation Classification (US FDGC 2008; USNVC 2017). Each association will be named by the diagnostic and often dominant species that occupy the different height strata (tree, shrub, and herb). Within the NatureServe Explorer database, ecological systems are numbered by a community Ecological System Code (CES) and individual vegetation associations are assigned an identification number called a Community Element Global Code (CEGL).
[*Caveat] The information presented is representative of very complex vegetation communities. Key indicator plants and ecological processes are described to help inform land management decisions. Plant communities will differ across the MLRA because of the naturally occurring variability in weather, soils, and geography. The reference plant community is not necessarily the management goal. The drafts of species lists are merely representative and are not botanical descriptions of all species occurring, or potentially occurring, on this site. They are not intended to cover every situation or the full range of conditions, species, and responses for the site.
The Very Wet Outwash ecological site, set in wet basins with saturated hydrologic conditions, is characterized by wetland plant communities with coastal affinities from Long Island, New York, north to Cape Cod, Massachusetts. These plant communities are mostly within the Northern Atlantic Coastal Plain Basin Peat Swamp system (CES203.522). The prevailing ecological processes are related to wetness, but also coastal influences, such as a coastal climate and storms, and if within close proximity to the coast, maritime effects of wind exposure, salt spray, and sand movement. These wetlands are quite varied and may be wet thickets dominated by hignbush blueberry (Vaccinium coryumbosum), swamp azalea (Rhododendron viscosum), and sweet pepperbush (Cletha alnifolia) or buttonbush (Cephalanthus occidentalis) and swamp loosestrife (Decodon verticillatus) or marshes of cattails (Typha spp.). Other swamp dominants may be red maple (Acer rubrum) and/or Atlantic white cedar (Chamaecyparis thyoides). Threats include drainage and conversion to develped land, invasives such as common reed (Phragmites australis). (Source: NatureServe 2018 [accessed 2019], USNVC 2017 [accessed 2019]).
State 1
Reference State (Very Wet Outwash)
The predominant plant communities of the Very Wet Outwash ecological site’s Reference State (minimally-managed) include:
• Blueberry Wetland Thicket, (Highbush Blueberry - Swamp Azalea - Coastal Sweet-pepperbush Acidic Peatland), {Vaccinium corymbosum - Rhododendron viscosum - Clethra alnifolia Acidic Peatland], - CEGL006371
• Northeastern Buttonbush Shrub Swamp, (Common Buttonbush - Swamp-loosestrife Shrub Swamp), [Cephalanthus occidentalis - Decodon verticillatus Shrub Swamp], - CEGL006069
Other common plant communities in more enriched conditions may include:
• Eastern Cattail Marsh, Cattail (Narrowleaf Cattail, Broadleaf Cattail) - (Bulrush species) Eastern Marsh), [Typha (angustifolia, latifolia) - (Schoenoplectus spp.) Eastern Marsh], - CEGL006153
• Lower New England Red Maple Swamp Forest, (Red Maple / Swamp Azalea - Coastal Sweet-pepperbush Swamp Forest), [Acer rubrum / Rhododendron viscosum - Clethra alnifolia Swamp Forest], - CEGL006156
• Coastal Plain Atlantic White Cedar Swamp Forest, (Coastal Plain Atlantic White Cedar Swamp Forest), [Chamaecyparis thyoides / Ilex glabra - Rhododendron viscosum Swamp Forest], - CEGL006188
(Source: NatureServe 2018 [accessed 2019], USNVC 2017 [accessed 2019]).
Community 1.1
Highbush Blueberry - Swamp Azalea - Coastal Sweet-pepperbush Thicket
Blueberry Wetland Thicket, (Highbush Blueberry - Swamp Azalea - Coastal Sweet-pepperbush Thicket), [Vaccinium corymbosum - Rhododendron viscosum - Clethra alnifolia Thicket], - CEGL006371
Typically, these associations occurs in small open basins, closed sandplain basins, and seasonally flooded zones within larger wetlands. It may also form as a result of beaver activity. This vegetation can occur on the margins of Coastal Plain ponds. This community is influenced by a strongly fluctuating water table with flooded conditions in spring and early summer followed by a drop in the water table below soil surface usually by late summer. Dominant shrubs include highbush blueberry (Vaccinium corymbosum), winterberry (Ilex verticillata), and swamp azalea (Rhododendron viscosum). Scattered red maple (Acer rubrum) are occasional. Maleberry (Lyonia ligustrina) and buttonbush (Cephalanthus occidentalis) are characteristic. Associated shrub species may include sweet pepperbush (Clethra alnifolia), rosy meadowsweet (Spiraea tomentosa), leatherleaf (Chamaedaphne calyculata), inkberry (Ilex glabra), swamp doghobble (Leucothoe racemosa), swamp loostriffe (Decodon verticillatus), sheep laurel (Kalmia angustifolia), smooth alder (Alnus serrulata), sweetgale (Myrica gale), and chokeberry (Aronia spp.). Herbaceous composition is variable; some of the more typical species include cinnamon fern (Osmunda cinnamomea), royal fern (Osmunda regalis), marsh fern (Thelypteris palustris), sensitive fern (Onoclea sensibilis), water arum (Calla palustris), northern water horehound (Lycopus uniflorus), Virginia marsh St. John’swort (Triadenum virginicum), fowl mannagrass (Glyceria striata), rice cutgrass (Leersia oryzoides), threeway sedge (Dulichium arundinaceum), common softrush (Juncus effusus), and Virginia chainfern (Woodwardia virginica). A layer of peatmoss (Sphagnum spp. may occur, including: Sphagnum fimbriatum, Sphagnum rubellum, Sphagnum magellanicum, Sphagnum fallax, and Sphagnum viridum. (Source: NatureServe 2018 [accessed 2019], USNVC 2017 [accessed 2019]).
Cross-referenced plant community concepts (typically by political state):
Shrub Swamp (Swain 2016) [MA]
Shrub Swamp (Edinger et al. 2014) [NY]
Blueberry wetland thicket (Sneddon et al. 2010) [Cape Cod National Seashore]
Community 1.2
Common Buttonbush - Swamp-loosestrife Shrub Swamp
Northeastern Buttonbush Shrub Swamp, (Common Buttonbush - Swamp-loosestrife Shrub Swamp), [Cephalanthus occidentalis - Decodon verticillatus Shrub Swamp], - CEGL006069
These swamps can experience prolonged or semipermanent flooding for much of the growing season, with water tables receding below the soil surface only during drought or very late in the growing season. They occur in a variety of environmental settings. Buttonbush (Cephalanthus occidentalis) is dominant and often monotypic. Occasional associates depend on the environmental setting and most often occur in drier areas. They include highbush blueberry (Vaccinium corymbosum), swamp azalea (Rhododendron viscosum), and possibly red maple (Acer rubrum) and dogwoods (Cornus spp). closer to upland borders or swamp loostriffe (Decodon verticillatus), leatherleaf (Chamaedaphne calyculata), and white meadowsweet (Spiraea alba var. latifolia) in more stagnant basins. Herbaceous species tend to be sparse but can include Canada mannagrass (Glyceria canadensis), threeway sedge (Dulichium arundinaceum), tussock sedge (Carex stricta), common woolsedge (Scirpus cyperinus), marshfern (Thelypteris palustris), rice cutgrass (Leersia oryzoides), European sweetflag (Acorus calamus), European waterplantain (Alisma plantago-aquatica), smartweeds/knitweeds (Polygonum spp.), (bur-reeds (Sparganium spp)., and possibly floating or submerged aquatic species such as duckweed (Lemna minor), pondweed (Potamogeton spp,) and variagated yello pondlily (Nuphar variegata). Bryophytes, if present, cling to shrub bases and include warnstofia moss (Warnstorfia fluitans), dreplanoclatus moss (Drepanocladus aduncus), or peatmoss (Sphagnum fallax). In disturbed areas, these wetland may be invaded by purple loosestrife (Lythrum salicaria). (Source: NatureServe 2018 [accessed 2019], USNVC 2017 [accessed 2019]).
Cross-referenced plant community concepts (typically by political state):
Shrub Swamp (Swain 2016) [MA]
Shrub Swamp (Edinger et al. 2014) [NY]
Northeastern Buttonbush Shrub Swamp (Sneddon et al. 2010) [Cape Cod National Seashore]
Pathway CP1.1-1.2
Community 1.1 to 1.2
disturbance, greater fire frequency, coastal proximity
Pathway CP1.2-1.1
Community 1.2 to 1.1
succession, lessor fire frequency
State 2
Semi-natural State
Vegetation on lands somewhat conditioned by land use, e.g., managed native plant communities or invasive plant communities.
Community 2.1
Managed wet woodland/thicket
Community 2.2
Invasive Plant Community
purple loosestrife (Lythrum salicaria), common reed (Phragmites australis)
Pathway CP2.1-2.1
Community 2.1 to 2.2
Invasive Plant establishment
Pathway CP2.2-2.1
Community 2.2 to 2.1
Invasive Plant Management
| Invasive Plant Species Control |
|
State 3
Cultural State
Landscapes heavily conditioned by land use, e.g., Plantations/gardens/cultivation(?)
Community 3.1
Cultivated/Cranberry Bogs(?)
cranberry (Vaccinium macrocarpon)
Transition T1-2
State 1 to 2
disturbance, invasive plant establishment
Transition T1-3
State 1 to 3
cutting, land clearing, plant establishment
| Brush Management |
|
| Land Clearing |
|
Restoration pathway R2-1
State 2 to 1
herbaceous weed treatment, plant removal, plant establishment, successional management
| Brush Management |
|
| Restoration and Management of Natural Ecosystems |
|
| Native Plant Community Restoration and Management |
|
| Forest Land Management |
|
| Invasive Plant Species Control |
|
| Monitoring and Evaluation |
|
Transition T2-3
State 2 to 3
cutting, land clearing, plant establishment
| Land Clearing |
|
| Invasive Plant Species Control |
|
| Herbaceous Weed Control |
|
Restoration pathway R3-1
State 3 to 1
herbaceous weed treatment, plant removal, plant establishment, successional management
| Brush Management |
|
| Restoration and Management of Natural Ecosystems |
|
| Native Plant Community Restoration and Management |
|
| Invasive Plant Species Control |
|
| Monitoring and Evaluation |
|
| Herbaceous Weed Control |
|
Transition T3-2
State 3 to 2
disturbance, invasive plant establishment
