Common (Translated Scientific) Name: Northern Bayberry / American Beachgrass - American Searocket Coastal Scrub & Herb Vegetation Division
Colloquial Name: Eastern North American Coastal Scrub & Herb Vegetation
Hierarchy Level: Division
Type Concept: This division is comprised of shrub and herbaceous upland vegetation growing on rapidly drained sandy and, occasionally, rocky substrates along the immediate coasts of the Great Lakes, the Gulf of Saint Lawrence, the Atlantic Ocean, the Gulf of Mexico, Lake Champlain, and possibly other large lakes in eastern North America. Stands occur on sites subjected to maritime processes of wave disturbance, constant wind, freezing spray, and/or salt spray. Settings include sandy to rocky upper beaches, foredunes, backdunes, rocky headlands, and sandplains. Species that are moderately to strongly diagnostic of this division include Ammophila breviligulata, Atriplex cristata, Atriplex glabriuscula var. acadiensis, Atriplex littoralis, Cakile edentula ssp. edentula, Cakile lanceolata, Carex silicea, Cenchrus tribuloides, Chamaesyce bombensis, Chamaesyce polygonifolia, Ceratiola ericoides, Chrysoma pauciflosculosa, Corema conradii, Croton punctatus, Helianthemum arenicola, Hudsonia ericoides, Hypericum kalmianum, Iva imbricata, Lathyrus japonicus, Lechea maritima, Ligusticum scoticum, Morella pensylvanica, Oenothera humifusa, Panicum amarum, Paronychia erecta, Paspalum monostachyum, Polygonum glaucum, Prunus maritima, Prunus pumila var. pumila, Schizachyrium littorale, Schizachyrium maritimum, Sesuvium maritimum, Solidago sempervirens, Triplasis purpurea, Uniola paniculata, and Yucca aloifolia. These species are largely strictly coastal species and are adapted to rapidly drained sandy substrates, maritime conditions imposed on local climate, and the impacts of maximum exposure to maritime storms and weather, which include frequent substrate disturbance and stress from wind, freezing spray, and/or salt spray.
Diagnostic Characteristics: Vegetation is comprised of shrub and herbaceous upland vegetation growing on rapidly drained sandy and, occasionally, rocky substrates along the temperate oceanic and Great Lakes coasts that is subjected to maritime processes of wave disturbance, constant wind, freezing spray, and/or salt spray. Species that are moderately to strongly diagnostic of this division include Ammophila breviligulata, Atriplex cristata, Atriplex glabriuscula, Atriplex littoralis, Cakile edentula ssp. edentula, Cakile lanceolata, Carex silicea, Cenchrus tribuloides, Chamaesyce bombensis, Chamaesyce polygonifolia, Ceratiola ericoides, Chrysoma pauciflosculosa, Corema conradii, Croton punctatus, Helianthemum arenicola, Hudsonia ericoides, Hypericum kalmianum, Iva imbricata, Lathyrus japonicus, Lechea maritima, Ligusticum scoticum, Morella pensylvanica, Oenothera humifusa, Panicum amarum, Paronychia erecta, Paspalum monostachyum, Polygonum glaucum, Prunus maritima, Prunus pumila var. pumila, Schizachyrium littorale, Schizachyrium maritimum, Sesuvium maritimum, Solidago sempervirens, Triplasis purpurea, Uniola paniculata, and Yucca aloifolia.
Rationale for Nominal Species or Physiognomic Features:
Classification Comments: This division is extremely heterogeneous along climatic (and associated biogeographical) gradients, reflecting the azonal nature of this type, though the coastal environment is consistent throughout. The macrogroup level accounts for the strong complex gradient of topography, soils and disturbances that distinguish beaches from dunes, whereas the climatic and biogeographical patterns within these categories are accounted for at the group level. There may be sufficient species turnover throughout the division, especially along a latitudinal gradient, to consider the splitting of this division into northern (cool-temperate) and southern (warm-temperate) units (i.e., elevating some group variation to division level). Analysis of representative floristic data across the entirety of these gradients would be useful in validating the current USNVC treatment or in elucidating a possible need for further adjustments.
In physiognomic and compositional aspects, shrublands of rocky headlands along the North Atlantic coast may be more related to inland shrublands of rocky northern areas (2.B.2.Nc Eastern North American Grassland & Shrubland Division (D024)) than to coastal (dune) shrublands included in this division.
Similar NVC Types:
D024 Eastern North American Grassland & Shrubland, note: interfaces inland along its entire range with this division. Vegetation of D024 lacks the species assemblages that are unique to the maritime setting, including its exposure to frequent storm disturbance. Some inland sites may be on sandy, rapidly drained sites that have broad floristic similarity to D026, but these stands can be distinguished by the usual absence of species that are strictly or primarily coastal in distribution [see Diagnostic Characteristics].
D146 Arctic Coastal Scrub & Herb Vegetation, note: occurs to the north of D026, and the two units share a number of species found in the northern areas of the latter division. Diagnostic criteria for the eastern part of the former division are currently not clear; the boundary between these divisions is in Canada.
D034 North American Atlantic & Gulf Coastal Salt Marsh, note: Sparsely vegetated upper beach stands of D026 intergrade with sparser (incipient) stands of D034 in the middle to inland side of barrier islands and spits, and the two units share some salt-tolerant ruderal species. Stands that can be assigned to the salt marsh D034 can be distinguished by a greater prevalence of hydrophytic, rather than upland, species, including pioneer individuals of the eventually dominant graminoid species (e.g., Spartina alterniflora, Distichlis spicata).
D102 Southeastern North American Grassland & Shrubland, note: interfaces inland along its entire range with this division. Vegetation of D0102 lacks the species assemblages that are unique to the maritime setting, including its exposure to frequent storm disturbance. Some inland sites may be on sandy, rapidly drained sites that have broad floristic similarity to D026, but these stands can be distinguished by the usual absence of species that are strictly or primarily coastal in distribution [see Diagnostic Characteristics].
D254 Caribbean-Mesoamerican Dune & Coastal Grassland & Shrubland, note: abuts this division (D026) in southern Florida and, possibly, along the south Texas Gulf Coast. The two divisions share species such as Batis maritima, Cakile lanceolata, Sesuvium portulacastrum, Sporobolus virginicus, and Uniola paniculata. The former division is distinguished by a predominance of characteristically tropical species, including Alternanthera maritima, Blutaparon vermiculare, Canavalia rosea, Chamaesyce mesembrianthemifolia, Coccoloba uvifera, Ipomoea pes-caprae, Piscidia piscipula, Pithecellobium keyense, Remirea maritima, Scaevola plumieri, and Suriana maritima.
Physiognomy and Structure: The cover and structure of vegetation are highly variable across the range of this division, ranging from dense shrub thickets to dense or sparse grasslands to very sparse, often succulent, annual plants.
Floristics: There is considerable geographic variation across the latitudinal and inland to oceanic ranges of this division. The primary regions of the taxa listed are given as Great Lakes (GL), North Atlantic (NA) (i.e., approximately Virginia and north), South Atlantic (SA) (approximately North Carolina and south), and Gulf Coast (GC).
Characteristic species of upper beach habitats include Amaranthus retroflexus (NA), Ambrosia artemisiifolia (all), Ammophila breviligulata (GL, NA), Argentina anserina (= Potentilla anserina) (GL), Artemisia campestris ssp. caudata (GL, NA), Atriplex cristata (= Atriplex mucronata, = Atriplex arenaria, = Atriplex pentandra) (NA, SA, GC), Atriplex glabriuscula var. acadiensis (= Atriplex acadiensis) (NA), Atriplex littoralis (NA), Atriplex prostrata (NA, SA), Batis maritima (SA, GC), Bidens spp. (GL), Cakile constricta (SA, GC), Cakile geniculata (GC), Cakile edentula ssp. edentula (including var. lacustris) (all), Cakile lanceolata (SA, GC), Cenchrus tribuloides (NA, SA, GC), Chamaesyce bombensis (= Euphorbia bombensis) (SA, GC), Chamaesyce polygonifolia (= Euphorbia polygonifolia) (GL, NA, SA), Chenopodium album (all), Cyperus spp. (all), Erechtites hieraciifolius (NA), Glaux maritima (= Lysimachia maritima) (NA), Heliotropium curassavicum (SA, GC), Honckenya peploides ssp. diffusa (= Arenaria peploides) (NA), Ipomoea imperati (SA, GC), Ipomoea sagittata (SA, GC), Lathyrus japonicus (GL, NA), Lepidium virginicum (NA, SA, GC), Mertensia maritima (NA), Panicum amarum var. amarum (NA, SA, GC), Polygonum spp. Section Persicaria (GL), Raphanus raphanistrum (NA), Salsola kali ssp. kali (= Salsola caroliniana) (NA, SA, GC), Sesuvium maritimum (SA, GC), Sesuvium portulacastrum (SA, GC), Sisymbrium spp. (GL, NA), Spartina patens (SA, GC), Sporobolus virginicus (SA, GC), Suaeda linearis (NA, SA, GC), Triplasis purpurea (NA, SA, GC), Vigna luteola (SA, GC), and Xanthium strumarium (NA, SA, GC). Amaranthus pumilus (NA, SA) and Polygonum glaucum (NA, SA) are somewhat rare, but fairly widely distributed, species.
Characteristic species of foredunes include Ammophila breviligulata (GL, NA), Ammophila champlainensis (Lake Champlain only), Andropogon virginicus (SA, GC), Artemisia campestris ssp. caudata (GL, NA), Artemisia stelleriana (NA), Calamovilfa longifolia (GL), Cenchrus tribuloides (NA, SA, GC), Chamaesyce polygonifolia (GL, NA, SA), Croton punctatus (SA, GC), Lathyrus japonicus (GL, NA), Leymus mollis (NA), Morella pensylvanica (NA), Oenothera humifusa (SA, GC), Panicum amarum var. amarum (NA, SA, GC), Physalis walteri (= Physalis maritima) (SA, GC), Prunus pumila var. pumila (GL), Rosa rugosa (NA), Solidago sempervirens (NA, SA, GC), Solidago simplex var. gillmanii (GL), Strophostyles helvola (NA, SA, GC), Triplasis purpurea (NA, SA, GC), and Uniola paniculata (SA, GC).
Characteristic taxa of more stabilized [back]dunes include Amelanchier canadensis (NA), Andropogon gerardii (all), Arctostaphylos uva-ursi (GL, NA), Aristida tuberculosa (NA), Carex pensylvanica (NA), Carex silicea (NA), Celastrus scandens (GL), Ceratiola ericoides (GC), Chrysoma pauciflosculosa (GC), Commelina erecta (SA, GC), Conyza canadensis (= Erigeron canadensis) (all), Cyperus grayi (NA), Danthonia spicata (GL, NA), Deschampsia flexuosa (GL, NA), Eustachys petraea (SA, GC), Gaillardia pulchella (SA, GC), Helianthemum spp. (= Crocanthemum spp.) (NA, SA, GC), Heterotheca subaxillaris (SA, GC), Hudsonia tomentosa (GL, NA), Hypericum kalmianum (GL), Iva imbricata (SA, GC), Juncus arcticus ssp. littoralis (= Juncus balticus) (GL), Juniperus communis (GL, NA), Juniperus horizontalis (GL, NA), Lechea maritima (NA), Maianthemum stellatum (= Smilacina stellata) (GL), Morella cerifera (= Myrica cerifera) (SA, GC), Morella pensylvanica (NA), Panicum amarum var. amarulum (SA, GC), Muhlenbergia capillaris (SA, GC), Opuntia humifusa (SA, GC), Opuntia pusilla (SA, GC), Panicum virgatum (all), Paronychia erecta (GC), Paspalum monostachyum (GC), Pityopsis falcata (= Chrysopsis falcata, = Heterotheca falcata) (NA), Polygonella articulata (= Polygonum articulatum) (GL, NA), Prunus maritima (NA), Prunus pumila var. pumila (GL), Rhus copallinum (= Rhus copallina) (NA), Rosa blanda (GL), Rosa rugosa (NA), Rosa virginiana (NA), Rubus flagellaris (NA, SA), Salix cordata (GL), Salix myricoides (= Salix glaucophylloides) (GL), Schizachyrium littorale (GL?, NA, SA, GC), Schizachyrium maritimum (GC), Schizachyrium scoparium (all), Shepherdia canadensis (GL), Smilax spp. (SA, GC), Solidago simplex var. gillmanii (GL), Sorghastrum nutans (NA, SA, GC), Spartina patens (SA, GC), Toxicodendron radicans (GL, NA), and Yucca spp. (SA, GC). Scattered trees, such as Juniperus virginiana var. silicicola (SA, GC), Pinus banksiana (GL), Pinus elliottii (GC), Pinus resinosa (GL), Pinus rigida (NA), Pinus strobus (GL), Pinus taeda (SE, GC), and/or Thuja occidentalis (GL) may occur.
Unusual expressions of the more stabilized dunes are sandplain grasslands and heathlands of the southern New England / New York coast (NA). Characteristic species include Amelanchier nantucketensis, Carex pensylvanica, Corema conradii, Deschampsia flexuosa, Gaylussacia baccata, Hudsonia ericoides, Hudsonia tomentosa, Ionactis linariifolius, Juncus greenei, Liatris scariosa var. novae-angliae (= Liatris novae-angliae), Morella pensylvanica, Schizachyrium scoparium, Sericocarpus linifolius, Symphyotrichum dumosum, and Vaccinium angustifolium.
On rocky headlands of northern New England and Canadian Maritime Provinces (NA), characteristic species include Achillea millefolium, Alnus incana ssp. rugosa, Amelanchier canadensis, Elymus repens (= Elytrigia repens), Empetrum nigrum, Festuca rubra, Gaylussacia baccata, Ilex mucronata, Juniperus horizontalis, Juniperus communis, Ligusticum scoticum, Maianthemum canadense, Morella pensylvanica, Parthenocissus quinquefolia, Aronia x prunifolia, Aronia melanocarpa, Plantago maritima, Prunus pensylvanica, Pteridium aquilinum var. latiusculum, Rosa virginiana, Rubus allegheniensis, Rubus idaeus ssp. strigosus (= Rubus strigosus), Symphyotrichum novi-belgii, Toxicodendron radicans, Trientalis borealis, Vaccinium angustifolium, Vaccinium vitis-idaea, and Viburnum nudum var. cassinoides.
Dynamics: The surface geology of the Atlantic coast south of southern Maine and that of the southern Great Lakes are dominated by sand deposits of Quaternary age that are subjected to continuous littoral processes, including deposition from longshore currents, which results in sandy spits and barrier islands. These features are periodically eroded by storm surges. The resultant cycle keeps the spits and islands relatively in place, but promotes relatively rapid changes in local (stand-scale) substrate. There is a gradient of decreasing disturbance frequency in an inland direction from the shoreline, with upper beaches experiencing relatively frequent disturbance, often at least annually, from water from storm surges. Smaller surges from abnormally high regular tides are more frequent along the North Atlantic coasts, where tidal amplitude is generally greater, but large surges may be more frequent along the South Atlantic and Gulf coasts due to more frequent exposure to hurricanes. The inundation tends to level the terrain, and the frequent disturbance favors relatively sparse or patchy communities of mostly annual plants.
Just inland from this zone, disturbance is less frequent, and incipient dunes begin to grow as wind-transported sand accumulates, beginning mostly around individual pioneer plants. Several rhizomatous perennial grass species that may become established on the upper beach, particularly Ammophila breviligulata in the north and Uniola paniculata in the south, grow rapidly as sand accumulates. In the absence of storm surge disturbance, dunes grow large enough to obstruct the incursion of all but the largest storm surges, and a foredune community dominated by these species is maintained under conditions of sand substrate being disturbed and deposited by wind. Inland from the foredunes or, as foredunes acquire more plant cover, the increased stabilization from wind disturbance allows less disturbance-tolerant species to colonize and contribute to a denser and more diverse backdune community, often with a more prominent shrub component.
In the glaciated Northeast, where glacial moraine deposits have provided extensive sources of sand, stands may occur well inland as extensive dune fields or "sandplains" (e.g., along the Great Lakes, Long Island and coastal southern New England, Ossipee region of New Hampshire and Maine) and may persist beyond the most active period of shoreline processes. Occasional fire or human use may maintain some of these (Motzkin and Foster 2002). On some barrier islands, grazing of dune grasses by wild horses may affect and even retard the progression of foredune development (De Stoppelaire et al. 2001). North of southern Maine and along the northernmost Great Lakes at the southern edge of the Canadian Shield (the northern shore of Lake Huron and much of Lake Superior), resistant bedrock begins to predominate along the more elevated parts of shorelines, and species that are well-adapted to substrate disturbance become less important.
In all communities and settings in this division, exposure to wind, freezing spray (in the northern latitudes), and salt deposition (along the Atlantic and Gulf coasts) strongly limit the vertical growth of woody vegetation and largely prevent succession to forests. Development of barrier islands and spits, along with the accompanying shoreline stabilizing construction (seawalls, high dunes, jetties) throughout the 20th century has not only usurped much of the habitat of this vegetation, but has also interrupted some of the longshore processes that renew the substrate and cycles of deposition that follow episodic erosion.
Geographic Range: This vegetation ranges from the Canadian Maritime Provinces south along the Atlantic and Gulf coasts to at least Texas. It also occurs along the shorelines of the Great Lakes and along a few other large lakes in the glaciated region (e.g., Lake Champlain, Lake Ossipee area). It almost always occurs within several kilometers of these shorelines.
States/Provinces: AL, CT, DE, FL, GA, IL, IN, LB?, MA, MD, ME, MI, MN, MS, NB?, NC, NF?, NH, NJ, NY, OH, ON, PA, PE?, QC?, RI, SC, TX, VA, VT, WI
|US Forest Service Ecoregions (2007)|
Southwest Plateau and Plains Dry Steppe and Shrub Province
Confident or certain
Confident or certain
Omernik Ecoregions: 34:C, 50:C, 51:C, 53:C, 54:C, 56:C, 57:C, 58:C, 59:C, 61:C, 63:C, 73:C, 75:C, 82:C, 83:C, 84:C, 5.2.3:C, 8.1.2:C, 8.1.9:C