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.
Thie Coastal Backbarrier Dune Flats ecological site is characterized by a wide mix of moderately well-drained plant communities coinciding with the Northern Atlantic Coastal Plain Dune and Swale system (CES203.264). In this environmental setting, this includes plant communities of dune backbarriers and flats that are not wet, yet moderately influenced by the watertable. The plant communities are quite small, generally not exceeding 0.1 ha (0.25 ac.) hence may be considered “patch” communities (Smith et al. 2008). The prevailing ecological processes are not only due to the maritime environment, including frequent salt spray, wind exposure, overwash, and sand movement, but also local effects due to fluctuating depths to seasonal water table, blowouts, dune migration, distance from salt-spray, and floristic succession. Other disturbances considered as threats include: off-road vehicles, and invasive plants, such as Morrows honeysuckle (Lonicera morrowii).
State 1
Reference State (minimally-managed)
Reference State
The range in reference plant communities is highly mixed due to variations in local conditions such as fluctuating depths to seasonal water table, blowouts, dune migration, distance from salt-spray, and floristic succession. The prevailing plant communities are shrubby, and differ from the more xeric stable dunes by the presence of plants influenced by nearby groundwater – including small amounts of switchgrass (Panicum virgatum), highbush blueberry (Vaccinium corymbosum), smooth [northern] arrow-wood (Viburnum dentatum var. lucidum [= V. recocognitum]), and red maple (Acer rubrum).
• Northern Bayberry Dune Shrubland (Northern Bayberry - Beach Plum Shrubland, [Morella pensylvanica - Prunus maritima Shrubland] – CEGL006295).
Other associated plant communities include:
• North Atlantic Coast Backdune Grassland ((Northern Bayberry) / Shore Little Bluestem - Seaside Three-awn Shrub Grassland, [(Morella pensylvanica) / Schizachyrium littorale - Aristida tuberculosa Shrub Grassland] – CEGL006161)
• Northern Beach-heather Dune Dwarf-shrubland (Woolly Beach-heather - Bearberry Dwarf-shrubland [Hudsonia tomentosa - Arctostaphylos uva-ursi Dwarf-shrubland] – CEGL006143), and
• North Atlantic Coastal Plain Dune Vine/shrubland (Cat Greenbrier - Eastern Poison-ivy Vine-Shrubland [Smilax glauca - Toxicodendron radicans Vine-Shrubland] – CEGL003886).
Community 1.1
Northern Bayberry - Beach Plum Shrubland (CEGL006295)
Northern Bayberry Dune Shrubland (Northern Bayberry - Beach Plum Shrubland, [Morella pensylvanica - Prunus maritima Shrubland] – CEGL006295) typically occurs on more stabilized dunes. Northern bayberry (Morella pensylvanica [= Myrica pensylvanica] and beach plum (Prunus maritima) dominate. Another common and often codominant shrub is seaside rose (Rosa rugosa), while not native, where naturalized it’s restricted to duneland sites. Other common shrubs or stunted trees in less abundance can include: eastern baccharis (Baccharis halimifolia) and sporatic red cedar (Juniperus virginiana) and black cherry (Prunus serotina). The herbaceous layer tends to be sparse where shrub growth is dense, and can include dune grassland species: American beachgrass (Ammophila breviligulata), seaside goldenrod (Solidago sempervirens), wooly beachheather (Hudsonia tomentosa), beach pinweed (Lechea maritima), Greene’s rush (Juncus greenei), seabeach sedge (Carex silicea), coastal jointweed (Polygonella articulata), annual saltmarsh American-aster (Symphyotrichum subulatum [= Aster subulatus]) or occasionally adjacent upland species such as, common wrinkleleaved goldenrod Solidago rugosa ssp.aspera, small flowered evening primrose (Oenothera parviflora),little bluestem (Schizachyrium scoparium), and others. Typical vine associates are poison ivy (Toxicodendron radicans), Virginia creeper Parthenocissus quinquefolia, and various Greenbriars (Smilax spp). Open, bare patches to sparsely vegetated sand are present in some (Source: NatureServe 2018 [accessed 2019], USNVC 2017 [accessed 2019]). Small amounts of highbush blueberry (Vaccinium corymbosum), sweet pepperbush (Clethra alnifolia), red maple (Acer rubrum), and black chokeberry (Aronia melanocarpa) are found in moister low areas (Enser et al. 2011).
Cross-referenced plant community concepts (typically by political state):
Maritime Shrubland (Swain 2016) [MA]
Maritime Shrubland (Edinger et al. 2014) [NY]
Maritime Herbaceous Dune (Enser et al. 2011 [RI]
Northern Bayberry Dune Shrubland (Sneddon et al 2010) [Cape Cod National Seashore]
Community 1.2
American Beachgrass - Beach Pea Grassland (CEGL006274)
Northern Beachgrass Dune, (American Beachgrass - Beach Pea Grassland, [Ammophila breviligulata - Lathyrus japonicus Grassland] - CEGL006274) is the typical community type. This association is characterized and dominated by American beechgrass (Ammophila breviligulata), which is often the only plant present, especially on foredunes or other areas of active and rapid sand deposition. Beach pea (Lathyrus japonicus) is the most common associate and sometimes codominant. Other associated species include seaside goldenrod (Solidago sempervirens), beach pinweed (Lechea maritima), seaside threeawn (Aristida tuberculosa), little bluestem (Schizachyrium scoparium), beach sedge (Carex silicea), coastal jointweed (Polygonella articulata), and dusty miller (Artemisia stelleriana). Dwarf-shrubs, such as wooly beachheather (Hudsonia tomentosa), beach rose (Rosa rugosa), northern bayberry (Morella pensylvanica [= Myrica pensylvanica]), or stunted beach plum (Prunus maritima), can occur sporadically and form patches within the grassland (Source: NatureServe 2018 [accessed 2019], USNVC 2017 [accessed 2019]).
Cross-referenced plant community concepts (typically by political state):
Maritime Dunes (Swain 2016) [MA]
Maritime Dunes (Edinger et al. 2014) [NY]
Maritime Herbaceous Dune (Enser et al. 2011 [RI]
Northern Beachgrass Dune (Sneddon et al 2010) [Cape Cod National Seashore]
Pathway CP 1.1-1.2
Community 1.1 to 1.2
disturbance
Pathway CP 1.2-1.1
Community 1.2 to 1.1
sucession
State 2
Semi-natural State
Invasives e.g. Japanese black pine (Pinus thunbergii), beach rose (Rosa rugosa), and Morrows honeysuckle (Lonicera morrowii).
State 3
Cultural State
Planting of Japanese Pine (Pinus thunbergii).
Community 3.1
Plantation
Planting of Japanese Pine (Pinus thunbergii).
Transition T1-2
State 1 to 2
disturbance, invasive plant establishment
Transition T1-3
State 1 to 3
cutting, land clearing, plant establishment, wind erosion control
Land Clearing |
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Herbaceous Weed Control |
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Restoration pathway R2-1
State 2 to 1
herbaceous weed treatment, plant removal, plant establishment, successional management
Land Clearing |
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Restoration and Management of Rare and Declining Habitats |
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Upland Wildlife Habitat Management |
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Restoration and Management of Natural Ecosystems |
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Invasive Plant Species Control |
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Herbaceous Weed Control |
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Transition T2-3
State 2 to 3
cutting, land clearing, invasive plant removal, plant establishment, wind erosion control
Land Clearing |
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Invasive Plant Species Control |
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Herbaceous Weed Control |
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Restoration pathway R3-1
State 3 to 1
herbaceous weed treatment, plant removal, plant establishment, successional management
Land Clearing |
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Restoration and Management of Rare and Declining Habitats |
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Restoration and Management of Natural Ecosystems |
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Herbaceous Weed Control |
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Transition T3-2
State 3 to 2
abandonment, disturbance, invasive plant establishment