Beach Dune

The beach dune community is a predominantly herbaceous community ofwide-ranging coastal specialists. It occurs on the upper beach and foredune, or first dune above the beach, which is built by perennial rhizomatous grasses growing upward from year to year as they are buried by sand blown inland off the beach. Sea oats is the most commonly encountered dune-former, a tall coarse grass capable of rapid lateral spread, forming a relatively sparse stand of tillers with internodes up to one foot apart (Wagner 1964). Two less common dune-forming grasses are beach cordgrass (Spartina patens) and bitter panicum (Panicum amarum var. amarulum). Several shrubs (Helianthus debilis, Croton punctatus, Scaevola plumieri, and Iva imbricata) can often be found growing between the widely spaced leaves in a patch of sea oats, along with two less frequent coastal shrubs, Argusia gnaphalodes and Suriana maritima. The upper beach in front of the sea oats foredune is a less stable habitat, being disturbed by seasonal or storm high tides annually or at least every few years, and is colonized by trailing vines: Ipomoea pes-capraeI. imperati, Canavalia rosea, and on the Atlantic coast: Alternanthera maritima and Okenia hypogaea, by low, spreading, halophytic grasses: Paspalum distichum, Sporobolus virginicus, and by driftline annuals: Cakile lanceolata, Salsola kali and Atriplex pentandra (Johnson and Muller 1993).

The discontinuous beaches of the Keys, the islands west of Key West, and the Ten Thousand Islands, which tend to be formed largely of shell fragments rather than quartz sands, have the same set of species as the mainland beaches, with a higher representation of the more tropical component, i.e., Suriana maritima, Argusia gnaphalodes, Ambrosia hispida, Hymenocallis latifolia, and Sesuvium portulacastrum (Kruer 1992, Davis 1942).

Taken from: U.S. Fish and Wildlife Service. 1999. South Florida Multi-Species Recovery Plan. Atlanta, Georgia. Pp. 3:72-73.

Listed Species Occurring in Beach Dune Habitat

  • Southeastern Beach Mouse
  • Roseate Tern
  • Piping Plover
  • Loggerhead Sea Turtle
  • Green Sea Turtle
  • Hawksbill Sea Turtle
  • Leatherback Sea Turtle
  • Kemp's Ridley Sea Trutle
  • Beach Jacquemontia