Physiognomy and Structure: The dynamic disturbance regimes largely limit the vegetation to pioneering, salt-tolerant, succulent annuals and perennial vines, which are more prevalent in these tropical examples in contrast to more northerly and temperate ones. The stands of vegetation are generally low in stature (with some clumps of taller grasses) and sparse to patchy in their cover.

Floristics: This group consists of the beach strand line, transitional dune, and stabilized coastal dunes with grasses and herbs. In the Caribbean islands, it occurs also in hard-packed sand areas behind sand beaches. Dunes are uncommon on Caribbean islands; open beaches are common. The following list of species is diagnostic for this group: Ambrosia hispida, Argusia gnaphalodes (= Mallotonia gnaphalodes, = Tournefortia gnaphalodes), Borrichia arborescens, Cakile lanceolata, Calotropis procera, Canavalia rosea (= Canavalia maritima), Cassia lineata, Cenchrus echinatus, Chamaesyce blodgettii (= Euphorbia blodgettii), Chamaesyce dioica, Chamaesyce mesembrianthemifolia (= Euphorbia buxifolia), Chrysobalanus icaco, Coccoloba uvifera, Croton punctatus, Cyperus planifolius, Egletes prostrata, Heliotropium nanum, Heterostachys ritteriana, Hippomane mancinella, Ipomoea pes-caprae, Iva imbricata, Lycium tweedianum (= Lycium nodosum), Opuntia caracassana, Piscidia piscipula, Pithecellobium keyense, Portulaca pilosa, Scaevola plumieri, Sesuvium portulacastrum, Spartina patens, Sporobolus virginicus, Tournefortia volubilis, Tribulus zeyheri, and Turnera diffusa. Along the Caribbean coast of Mexico and Central America, plants include Acoelorraphe wrightii, Bromus sp., Clitoria falcata (= Clitoria rubiginosa), Crotalaria retusa, Dactyloctenium aegyptium, Dodonaea sp., Hibiscus tiliaceus, Hymenocallis littoralis, Manicaria sp., Mimosa pudica, Morinda citrifolia, Phyllanthus acidus, Sphagneticola trilobata (= Wedelia trilobata), Stachytarpheta jamaicensis, and Tridax procumbens. On isolated dunes there are short trees or shrubs of Conocarpus erectus, Prosopis juliflora, and Acacia tortuosa. Cocos nucifera is a common introduced palm, and the introduced tree Casuarina equisetifolia has been planted along the coast in Florida, the Bahamas, and the Caribbean. Other invasive exotic plants in coastal strand in south Florida include Colubrina asiatica, Cupaniopsis anacardioides, Neyraudia reynaudiana, Scaevola sericea var. taccada (= Scaevola taccada), and Schinus terebinthifolius (FNAI 2010a).

Dynamics:  The process of sand movement due to the forces of wind and water is part of the natural dynamics of beach ecosystems. This includes transport of sand along the coast, and movement of sand by wind or water between the dunes, beach and subtidal areas. If not restricted by infrastructure or engineered hard structures, beaches and dunes can migrate as coastlines change over time in response to the action of wind and water (Defeo et al. 2009). Coastal engineering such as seawalls and other hard structures are among the threats to the natural dynamics of the beach (Defeo et al. 2009). Dunes are best developed along the Atlantic Coast of Florida; many beaches in the Caribbean lack dunes. Plants on the foredune are regularly exposed to salt spray and sand burial from onshore winds. Plants on the upper beach are subject to these stresses plus occasional inundation by seasonal or storm tides and periodic destruction by waves. The plants of the beach dune community are adapted to either withstand these stresses or to rapidly re-colonize from seed or vegetative parts following destruction. Fertilization from piles of seaweed washed up by storms helps to speed plant growth and the re-colonization process. Once a new foredune ridge blocks salt spray and plant cover inhibits sand movement, inland herbaceous and eventually woody species can begin to replace the coastal pioneer species of the beach dune community in the backdune area. The coastal berm is deposited by storm waves along low-energy coasts. Their distance inland depends on the height of the storm surge. Tall berms may be the product of repeated storm deposition. Excavation of one berm in the Florida Keys revealed several layers of buried soils, evidence of burial by repeated storms at relatively long intervals (Kruer 1992, as cited in FNAI 2010a).