Coastal Communities

In each of the communities covered, a photograph of the community is accompanied by a description of the soil conditions favored, the distribution of the community, and other points of interest. This summary is followed by two lists; the list entitled 'typical indicator species' includes plant species which tend to be dominant and typify the community. The second list, entitled 'Species to watch for' includes some of the rarer species which - in our area at least - tend to favor this community. Becoming familiar with the commoner species and their association with each other can be a good step toward finding rarer or more interesting plants.

Sandy Beaches

Sandy Beaches Sandy Beaches Sandy Beaches
A beach with a natural community of
coastal plants.
Managed beach with dune cross-overs. Beaches that allow access to vehicles
are devoid of natural plant communities.

Beaches present extremely hostile environments for plants to colonize, so it is perhaps not surprising that few species manage to survive the conditions. The mechanical action of waves prevents colonization below the high water mark, but a number of species survive along the wrack line and beyond to the edge of the dunes. Such salt tolerant plants are known as halophytes. The dynamic behavior of the habitat means that only annual plants are able to survive and populations of plants vary widely from year to year according to survival rates over winter.

Such plant communities are clearly fragile and easily disrupted; despite this, free vehicular access to many beaches is widely permitted in the region and plant communities of sandy beaches are threatened as a result. As stated, few plants have been able to evolve to survive in these habitats, but the goosefoot family stands out as an exception. One of the rarest plants in New Jersey, Seabeach Amaranth, just survives in the state where protected in these habitats, but it seems to have been exterpated in Cape May County. In the most stable locations, American Beach-grass becomes established and this can be the beginning of a sand dune community.

Typical indicator species
  • Purple Sand-grass
  • Bitter Panic-grass (var. amarum)
  • Sand-dune Bur-grass
  • Seaside Sandmat
  • Seaside Evening-primrose
  • American Sea Rocket
  • Desert Goosefoot
  • Prickly Saltwort
  • Species to watch for
  • Crested Orache
  • Russian-thistle

  • Coastal Primary Dunes

    Coastal Primary Dunes Coastal Primary Dunes Coastal Primary Dunes
    Typical primary dune with stands of
    Bitter Panic-grass, backed by low
    Northern Bayberry.
    Stabilized dunes becoming colonized by
    Beach Goldenrod.
    Stabilized dunes colonized by woody
    perennials including Japanese Rose.

    Immediately behind - or at the upper edge of - a sandy beach, beyond the reach of normal spring tides, sands and other particles begin to settle down and become influenced more by wind than water action. Particles of different size settle out during wind movement and dunes begin to form. This provides a relatively stable environment for the first perennial plants to become established and these, in turn, further stabilize the sands.

    Primary dunes consist largely of a handful of grass species that are able to colonise the mobile sands and begin the process of stabilization. These consist largely of American Beach-grass, Bitter Panic-grass (of two subspecies) and Salt-meadow Cord-grass of the coastal dune form. After this initial colonization, the more stabilized sands offer suitable habitat for a range of other plant species and the transition to established coastal dunes will begin. Usually prominant among these early plant communities are Seaside Goldenrod, Trailing Fuzzy-bean and Rough Cocklebur, while the first woody plants also start to appear in the form of low individuals of Northern Bayberry, Eastern Poison-ivy and Eastern Baccharis.

    Some coastal dune communities are threatened by colonization by alien plant species, often originating from garden plants, deliberately planted at the edge of the dunes, but also by self-sown individuals. Some primary dunes are currently being colonized by Japanese Rose (often mistakenly believed to be native in New Jersey when sold under the alternate name of Rugosa Rose) and the highly invasive Asiatic Sand Sedge.
    Typical indicator species
  • Gray's Flat-sedge
  • American Beach-grass
  • Salt-meadow Cord-grass
  • Matting Panic-grass
  • Bitter Panic-grass (var. amarum)
  • Bitter Panic-grass (var. amarulum)
  • Sand-dune Bur-grass
  • Coast Beard-grass
  • Trailing Fuzzy-bean
  • Seaside Goldenrod
  • Rough Cocklebur
  • Species to watch for
  • Asiatic Sand Sedge
  • Common Rattlebox
  • Woolly Hudsonia
  • Coast Jointweed
  • Slender Sea-purslane

  • Established Coastal Dunes

    Established Coastal Dunes Established Coastal Dunes Established Coastal Dunes
    Windblown dune systems with well-
    established plant communities are now
    rare, but can still be found at Higbee
    Established dunes with mixed woody
    plant communities and open areas
    dominated by Coast Beard-grass and
    other low plants.
    Low dune scrub develops in open areas
    (such as around inlets) where exposure
    to weather effects prevents the develop-
    ment of dune forest.

    Over time, the stabilization of primary dunes leads to further colonization by a wider range of plant species, in particular woody trees and shrubs, resulting in the establishment of a suite of plant communities typical of coastal sandy soils. Primary woody plant species include Eastern Poison-ivy and Northern Bayberry, with Virginia Juniper and Black Cherry soon following. In lower lying spots that hold more water and thus provide damper soils, Eastern Baccharis also becomes common. Eventually, species such as Post Oak and Southern Red Oak become established and the habitats can transition into coastal dune forest or other dry woodland communities.

    Well-established primary dunes in the Cap May area have been extensively converted to housing throughout the coastal barrier island region and good examples of these plant communities are now rare. In addition, restricted access to coastal dune ecosystems makes it difficult to visit such communities. However, at least some protection in the Avalon and Stone Harbor areas offers opportunites to understand the complex of communities that make up these interesting areas. Higher dune systems will tend to have relatively species-poor communities, consiting mostly of woody plants that can produce root systems extensive enough to reach down to available water. Also, such sand dune systems often consist of mobile, wind-blown sands that pile up and can bury vegetation. Thus, the only plants remaining are often the tops of submerged trees.

    In lower-lying areas between the dunes, wetter habitats often develop, holding water from winter rains, before drying out during the summer months. These communities generally consist of the same plant species as are found in vernal ponds, often with a high number of rushes and flat-sedges, or developing as cat-tail marsh if wet enough.

    Typical indicator species
  • Virginia Juniper
  • Glaucous Greenbrier
  • Japanese Rose
  • Beach Plum
  • Dwarf Hackberry
  • Northern Bayberry
  • Slender Snakecotton
  • Spotted Beebalm
  • Seaside Goldenrod
  • Species to watch for
  • Starry False Solomon’s-seal
  • Drummond’s Rockcress

  • Low Saltmarsh

    Low Saltmarsh Sandy Beaches Sandy Beaches
    Dense stand of Virginia Glasswort on
    low saltmarsh.
    Stands of Virginia Glasswort on muddy
    'pans' are most obvious when they turn
    red in the fall.
    Eroding mid saltmarsh community
    showing a steep muddy profile with no
    low saltmarsh community.

    Saltmarsh communities make up a large proportion of the plant communities in Cape May County. These communities develop in areas where saltwater has an influence on the soil, with different communities developing according to the regularity of saltwater inundation. The communities with the most saltwater tolerance are those that develop below the low water mark and consist largely of seaweeds and beds of eel-grass. Above the low water mark, areas of bare mud are colonized by stands of succulent plants, capable of surviving the extreme conditions. The presence of these plants is significant, as their root systems begin the process of stabilizing the muddy sediments and provide conditions for permanent saltmarsh communities to develop.

    These low saltmarsh communities tolerate the highest number of saltwater inundations per year and most of the plants are annuals, regenerating from seed each spring. These communities develop most successfully in areas where sediment is settling out, such as on the inside corner of bends in creeks; they also tend to occur on open, mud 'pans' within stands of mid saltmarsh communities. In areas where the saltmarsh is eroding due to tidal action, mid saltmarsh communities occur to the water's edge and there is usually a steep bank rather than a gentle slope down to the water.

    Typical indicator species
  • Virginia Glasswort
  • Dwarf Glasswort

  • Mid Saltmarsh

    Mid Saltmarsh Sandy Beaches Sandy Beaches
    Stands of short and tall ecotypes of
    Smooth Cord-grass dominate vast
    areas of saltmarsh.
    Saltmarsh plant communities can form
    a complex mosaic, with a mix of taller
    herbaceous perennials on drier ground
    and dense stands of Common Reed
    covering dredging impoundments.
    Mid saltmarsh communities have to
    withstand complete inundation by
    saltwater during the highest spring
    tides and such inundations appear to
    be increasing in frequency.

    Above the level of low saltmarsh lie areas that receive fewer saltwater inundations, though still enough that survival here is very difficult for plants and only a very few species have evolved to survive the conditions. Vast, open areas of mid saltmarsh plant communities cover much of the land between the barrier islands and the higher ground to the west of the Garden State Parkway. These areas are mostly dominated by a single species, Smooth Cord-grass, which occurs in two main ecotypes. The tall ecotype forms single-species stands in wetter, looser sediment and often grows along the edges of narrow creeks within the saltmarsh. The shorter ecotype forms extensive swards on firmer substrates and is often mixed with a range of other saltmarsh plant species. At the upper edge of the marsh, these communities form a mosaic with areas of high saltmarsh.

    Within the open expanses of saltmarsh, subtle differences in sediment type and perhaps levels of saltwater inundation, produce variety in the plant communities. Stands of Marsh Spike-grass can be quite extensive in some areas, while colonies of Carolina Sea-lavender color the marsh with their pale purple flowers in late summer. Areas of bare mud are colonised by glassworts and Tall Sea-blite, with American Perennial Glasswort being particularly successful at colonizing harder substrates around the edges of boat ramps, wet parking lots and similar places.

    Typical indicator species
  • Marsh Spike-grass
  • Smooth Cord-grass
  • Carolina Sea-lavender
  • American Perennial Glasswort
  • Virginia Glasswort
  • Dwarf Glasswort
  • Tall Sea-blite
  • Species to watch for
  • Large Cord-grass
  • Sea Plantain

  • High Saltmarsh

    High Saltmarsh Sandy Beaches
    At the higher edge of saltmarsh stands,
    Common Cord-grass gives way to Salt-
    meadow Cordgrass and Saltmarsh Rush.
    Brackish ponds or lagoons are fringed
    with stands of various bulrushes and
    related plants, which gradually give
    way to cattail marsh.

    Rising ground eventually comes out of the influence of saltwater inundation and freshwater takes over as the water source for plants. The interface between mid saltmarsh and high saltmarsh is complex and involves a number of influences. Undulations in the ground allow saltwater incursion in some areas, while freshwater springs rising from the ground can produce isolated areas of freshwater plant communities within the saltmarsh. Much of the interface between salt-influenced and freshwater-influenced plant communities was lost when the Garden State Parkway was built and any surviving areas were subsequently swamped by invasive stands of alien Common Reed.

    In open saltmarsh areas, high saltmarsh is often marked by a relatively narrow band of shrubby plants, mostly Common Marsh-elder and Eastern Baccharis, with many of the herbaceous plants of high saltmarsh being found in mixed communities on rising ground around the base of these shrubs. These stands are intermingled with areas of Saltmarsh Rush. In wetter areas, brackish lagoons are bordered by stands of high saltmarsh vegetation that are often dominated by Saltmarsh Bulrush and Olney's Bulrush, interspersed with carpets of Saltmarsh Fleabane.

    On the barrier islands, the vast majority of high saltmarsh has been completely lost, with holiday homes built right out from the higher ground of the dunes to the mid saltmarsh such that, at high tide, saltwater inundates the marsh right up to the level of streets and houses. Here, an impoverished highmarsh plant community survives patchily on areas of bare ground along roadsides, where there is enough saltwater inundation to preclude the growth of other plant species.

    High saltmarsh communities were once much more common than they are today and, where Salt-meadow Cord-grass and Marsh Spike-grass once dominated, salt hay farms proliferated. An increasing number of higher spring tides, increasing saltwater inundations and other factors have caused changes to the ecology of saltmarsh habitats and these high saltmarsh communities and their attendant wildlife seem now to be lost.

    Typical indicator species
  • Saltmarsh Rush
  • Saltmarsh Bulrush
  • Fern Flat-sedge
  • Marsh Spike-grass
  • Salt-meadow Cord-grass
  • Saltmarsh Cockspur-grass
  • Perennial Bristle-grass
  • Prolific Knotgrass
  • Saltmarsh Sea-spurrey
  • American Germander
  • Saltmarsh Fleabane
  • Eastern Baccharis
  • Perennial Saltmarsh Aster
  • Annual Saltmarsh Aster
  • Common Marsh-elder
  • Species to watch for
  • Olney’s Bulrush
  • Marsh Fimbry
  • Narrow-leaved Loosestrife
  • Saltmarsh Amaranth
  • Saltmarsh False-foxglove

  • Dry Salt Habitats

    Dry Salt Habitats Dry Salt Habitats
    Open expanses of salt-laden mud
    provide a tough habitat for plants with
    few species able to tolerate the harsh
    Extensive stands of Summer-cypress
    form a plant community on the edges
    of dredging impoundments.

    In addition to natural coastal habitats, soils with a high salt content also occur in certain man made habitats. Around Cape May, chief among these are dredging impoundments. These consist of alluvial deposits dredged from saltmarsh channels and the Cape May canal and these deposits will have a high salt content. Few plant species are able to grow in these soils, but one or two saltmarsh species, as well as species more typically found in salt lake habitats, take advantage of these conditions.

    Impoundments generally consist of large, open areas of drying mud, which become baked in the sun and cracked. Saltworts, glassworts and related species grow sparsely in these areas. Around the edges of the impoundments, where there is mixing with other soils and consequently less salt content, a few other species can take hold, most notably Summer-cypress and Mexican-tea. Eventually, Common Reed will often become dominant, often to the exclusion of all other species.

    Smaller areas of bare ground with high salt content can also be found along the edges of roads, either where they cross saltmarsh habitat, or where salt is applied to the road during the winter. These areas often hold an interesting array of saltmarsh species, creating new plant communities that are human influenced. Low, spreading communities of Saltmarsh Sea-spurrey, Winged Pigweed, Hairy Smotherweed, Tall Sea-blite, Prolific Knotweed, Virginia Glasswort and Annual Saltmarsh Aster are typically found in such places.

    Typical indicator species
  • Prolific Knotgrass
  • Saltmarsh Sea-spurrey
  • Winged Pigweed
  • Mexican-tea
  • Hairy Smotherweed
  • Summer-cypress
  • Spear-leaved Orache
  • Virginia Glasswort
  • Tall Sea-blite
  • Annual Saltmarsh Aster
  • Species to watch for
  • Annual Sea-blite
  • Slender Sea-purslane