COASTAL DUNES & PONDS (128)
(formerly termed Coastal Dunes

Geographic Distribution. The coastal dunes of Oregon attain their greatest development between Florence and Coos Bay where they form a continuous surface that extends several miles inland. Dunes can form through a variety of processes that are influenced by local topography, prevailing wind direction, and source supply of sand. While dunes can be found throughout the length of the Oregon coast they mostly are small, discrete features that do not show up in the vegetation map.

Structure and Appearance. Coastal dunes, as they relate to this vegetation description, are sparsely vegetated. Dunes are regions of actively moving sand and only a few types of plants. Typically, grasses or grasslike plants do well in this environment., and typically are grasses or grass-like plants.

Composition. The most commonly encountered plants encountered on these dunes are European beach grass (Ammophila arenaria), seashore bluegrass (Poa macrantha), American dune grass (Elymus mollis) and large-headed sedge (Carex macrocephala). Other forbs are beach morning glory (Convolvulus soldanella), beach knotweed (Polygonum paronychia), yellow abronia (Abronia latifolia) and silver beach weed (Franseria chamissonis).

Landscape Setting. Coastal dunes can appear as a mosaic with coastal forest, estuarine and palustrine wetlands and coastal strand vegetation.

References. Weideman et al. 1974, Ripley 1984